Author: "M. Flasiński" - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"M. Flasiński"' showing total 57 results

Start Over Author "M. Flasiński"

57 results on '"M. Flasiński"'

1. EXTRACTION OF THE GLUON DENSITY OF THE PROTON AT X

Author: M. Derrick, D. Krakauer, S. Magill, B. Musgrave, J. Repond, J. Schlereth, R. Stanek, R.L. Talaga, J. Thron, F. Arzarello, R. Ayad, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, P. Bruni, G. Cara Romeo, G. Castellini, M. Chiarini, L. Cifarelli, F. Cindolo, F. Ciralli, A. Contin, S. D'Auria, F. Frasconi, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi, A. Margotti, T. Massam, R. Nania, C. Nemoz, F. Palmonari, A. Polini, G. Sartorelli, R. Timellini, Y. Zamora Garcia, A. Zichichi, A. Bargende, J. Crittenden, K. Desch, B. Diekmann, T. Doeker, M. Eckert, L. Feld, A. Frey, M. Geerts, G. Geitz, M. Grothe, H. Hartmann, D. Haun, K. Heinloth, E. Hilger, H.-P. Jakob, U.F. Katz, S.M. Mari, A. Mass, S. Mengel, J. Mollen, E. Paul, Ch. Rembser, R. Schattevoy, D. Schramm, J. Stamm, R. Wedemeyer, S. Campbell-Robson, A. Cassidy, N. Dyce, B. Foster, S. George, R. Gilmore, G.P. Heath, H.F. Heath, T.J. Llewellyn, C.J.S. Morgado, D.J.P. Norman, J.A. O'Mara, R.J. Tapper, S.S. Wilson, R. Yoshida, R.R. Rau, M. Arneodo, L. Iannotti, M. Schioppa, G. Susinno, A. Bernstein, A. Caldwell, J.A. Parsons, S. Ritz, F. Sciulli, P.B. Straub, L. Wai, S. Yang, P. Borzemski, J. Chwastowski, A. Eskreys, K. Piotrzkowski, M. Zachara, L. Zawiejski, L. Adamczyk, B. Bednarek, K. Eskreys, K. Jelén, D. Kisielewska, T. Kowalski, E. Rulikowska-Zarȩbska, L. Suszycki, J. Zaja̧c, T. Kȩdzierski, A. Kotański, M. Przybycień, L.A.T. Bauerdick, U. Behrens, J.K. Bienlein, S. Böttcher, C. Coldewey, G. Drews, M. Flasiński, D.J. Gilkinson, P. Göttlicher, B. Gutjahr, T. Haas, W. Hain, D. Hasell, H. Heβling, H. Hultschig, Y. Iga, P. Joos, M. Kasemann, R. Klanner, W. Koch, L. Köpke, U. Kötz, H. Kowalski, W. Kröger, J. Krüger, J. Labs, A. Ladage, B. Löhr, M. Löwe, D. Lüke, O. Mańczak, J.S.T. Ng, S. Nickel, D. Notz, K. Ohrenberg, M. Roco, M. Rohde, J. Roldán, U. Schneekloth, W. Schulz, F. Selonke, E. Stiliaris, T. Voβ, D. Westphal, G. Wolf, C. Youngman, H.J. Grabosch, A. Leich, A. Meyer, C. Rethfeldt, S. Schlenstedt, G. Barbagli, P. Pelfer, G. Anzivino, G. Maccarrone, S. De Pasquale, S. Qian, L. Votano, A. Bamberger, A. Freidhof, T. Poser, S. Söldner-Rembold, J. Schroeder, G. Theisen, T. Trefzger, N.H. Brook, P.J. Bussey, A.T. Doyle, I. Fleck, V.A. Jamieson, D.H. Saxon, M.L. Utley, A.S. Wilson, A. Dannemann, U. Holm, D. Horstmann, H. Kammerlocher, B. Krebs, T. Neumann, R. Sinkus, K. Wick, E. Badura, B.D. Burow, A. Fürtjes, L. Hagge, E. Lohrmann, J. Mainusch, J. Milewski, M. Nakahata, N. Pavel, G. Poelz, W. Schott, J. Terron, F. Zetsche, T.C. Bacon, R. Beuselinck, I. Butterworth, E. Gallo, V.L. Harris, B.H. Hung, K.R. Long, D.B. Miller, P.P.O. Morawitz, A. Prinias, J.K. Sedgbeer, A.F. Whitfield, U. Mallik, E. McCliment, M.Z. Wang, S.M. Wang, J.T. Wu, Y. Zhang, P. Cloth, D. Filges, S.H. An, S.M. Hong, S.W. Nam, S.K. Park, M.H. Suh, S.H. Yon, R. Imlay, S. Kartik, H.-J. Kim, R.R. McNeil, W. Metcalf, V.K. Nadendla, F. Barreiro, G. Cases, R. Graciani, J.M. Hernández, L. Hervás, L. Labarga, J. del Peso, J. Puga, J.F. de Trocóniz, F. Ikraiam, J.K. Mayer, G.R. Smith, F. Corriveau, D.S. Hanna, J. Hartmann, L.W. Hung, J.N. Lim, C.G. Matthews, P.M. Patel, L.E. Sinclair, D.G. Stairs, M. St.Laurent, R. Ullmann, G. Zacek, V. Bashkirov, B.A. Dolgoshein, A. Stifutkin, G.L. Bashindzhagyan, P.F. Ermolov, L.K. Gladilin, Y.A. Golubkov, V.D. Kobrin, V.A. Kuzmin, A.S. Proskuryakov, A.A. Savin, L.M. Shcheglova, A.N. Solomin, N.P. Zotov, S. Bentvelsen, M. Botje, F. Chlebana, A. Dake, J. Engelen, P. de Jong, M. de Kamps, P. Kooijman, A. Kruse, V. O'Dell, A. Tenner, H. Tiecke, W. Verkerke, M. Vreeswijk, L. Wiggers, E. de Wolf, R. van Woudenberg, D. Acosta, B. Bylsma, L.S. Durkin, K. Honscheid, C. Li, T.Y. Ling, K.W. McLean, W.N. Murray, I.H. Park, T.A. Romanowski, R. Seidlein, D.S. Bailey, G.A. Blair, A. Byrne, R.J. Cashmore, A.M. Cooper-Sarkar, D. Daniels, R.C.E. Devenish, N. Harnew, M. Lancaster, P.E. Luffman, L. Lindemann, J. McFall, C. Nath, A. Quadt, H. Uijterwaal, R. Walczak, F.F. Wilson, T. Yip, G. Abbiendi, A. Bertolin, R. Brugnera, R. Carlin, F. Dal Corso, M. De Giorgi, U. Dosselli, S. Limentani, M. Morandin, M. Posocco, L. Stanco, R. Stroili, C. Voci, J. Bulmahn, J.M. Butterworth, R.G. Feild, B.Y. Oh, J.J. Whitmore, G. D'Agostini, M. Iori, G. Marini, M. Mattioli, A. Nigro, E. Tassi, J.C. Hart, N.A. McCubbin, K. Prytz, T.P. Shah, T.L. Short, E. Barberis, N. Cartiglia, T. Dubbs, C. Heusch, M. Van Hook, B. Hubbard, W. Lockman, J.T. Rahn, H.F.-W. Sadrozinski, A. Seiden, J. Biltzinger, R.J. Seifert, A.H. Walenta, G. Zech, H. Abramowicz, G. Briskin, S. Dagan, A. Levy, T. Hasegawa, M. Hazumi, T. Ishii, M. Kuze, S. Mine, Y. Nagasawa, T. Nagira, M. Nakao, I. Suzuki, K. Tokushuku, S. Yamada, Y. Yamazaki, M. Chiba, R. Hamatsu, T. Hirose, K. Homma, S. Kitamura, S. Nagayama, Y. Nakamitsu, R. Cirio, M. Costa, M.I. Ferrero, L. Lamberti, S. Maselli, C. Peroni, R. Sacchi, A. Solano, A. Staiano, M. Dardo, D.C. Bailey, D. Bandyopadhyay, F. Benard, M. Brkic, M.B. Crombie, D.M. Gingrich, G.F. Hartner, K.K. Joo, G.M. Levman, J.F. Martin, R.S. Orr, C.R. Sampson, R.J. Teuscher, C.D. Catterall, T.W. Jones, P.B. Kaziewicz, J.B. Lane, R.L. Saunders, J. Shulman, K. Blankenship, J. Kochocki, B. Lu, L.W. Mo, W. Bogusz, K. Charchuł, a, J. Ciborowski, J. Gajewski, G. Grzelak, M. Kasprzak, M. Krzyżanowski, K. Muchorowski, R.J. Nowak, J.M. Pawlak, T. Tymieniecka, A.K. Wróblewski, J.A. Zakrzewski, A.F. Zarnecki, M. Adamus, Y. Eisenberg, C. Glasman, U. Karshon, D. Revel, A. Shapira, I. Ali, B. Behrens, S. Dasu, C. Fordham, C. Foudas, A. Goussiou, R.J. Loveless, D.D. Reeder, S. Silverstein, W.H. Smith, T. Tsurugai, S. Bhadra, W.R. Frisken, and K.M. Furutani
Subjects: Nuclear and High Energy Physics, Particle physics, Proton, Nuclear physics, INELASTIC MUON SCATTERING, DEUTERON STRUCTURE FUNCTIONS, ZEUS, NUCLEON STRUCTURE FUNCTIONS, HIGH STATISTICS MEASUREMENT, PARTON DISTRIBUTIONS, LEADING ORDER, HIGH Q2, PERTURBATION-THEORY, SCALING VIOLATIONS, PP COLLISIONS, Quantum chromodynamics, Physics, ZEUS (particle detector), Neutral current, Scattering, High Energy Physics::Phenomenology, HERA, Gluon, High Energy Physics::Experiment, Perturbation theory (quantum mechanics)
Abstract: The gluon momentum density xg ( x , Q 2 ) of the proton was extracted at Q 2 = 20 GeV 2 for small values of x between 4 × 10 −4 and 10 −2 from the scaling violations of the proton structure function F 2 measured recently by ZEUS in deep inelastic neutral current ep scattering at HERA. The extraction was performed in two ways. Firstly, using a global NLO fit to the ZEUS data on F 2 at low x constrained by measurementsfrom NMC at larger x ; and secondly using published approximate methods for the solution of the GLAP QCD evolution equations. Consistent results are obtained. A substantial increase of the gluon density is found at small x in comparison with the NMC result obtained at larger values of x .
Published: 2016
Full Text: View/download PDF

2. Study of charged—currentep interactions atQ 2>200 GeV2 with the ZEUS detector at HERA

Author: WN Cottingham, D.D. Reeder, M. Wodarczyk, H. Park, P. B. Kaziewicz, H. Uijterwaal, U. Wollmer, Roberto Sacchi, Ulf Behrens, H.G.J.M. Tiecke, B. Surrow, F. Benard, M.A.J. Botje, Fernando Barreiro, S. Mengel, J. Mainusch, J.B. Lane, Gy. Wolf, Yasunori Yamazaki, D. Simmons, Avto Kharchilava, W. Schott, Cd Catterall, Federico Cindolo, R. R. McNeil, W. Bogusz, Cristiana Peroni, Aharon Levy, Thomas Trefzger, K.F. Johnson, J. N. Lim, Mauro Morandin, Z. Jakubowski, Ricardo Graciani, Samuel Silverstein, H.-P. Jakob, John Hart, P. Nylander, K. K. Joo, A. Bruni, L. W. Hung, F. Palmonari, R. Sinkus, O. Mańczak, G. F. Hartner, R. J. Cashmore, Miriam Lucio Martinez, S. B. Lee, Andrea Contin, A. Kruse, S. Wölfle, Laurel E. Sinclair, M. Löwe, Katsuo Tokushuku, L. Hagge, Antonino Zichichi, Aleksander Filip Żarnecki, Silvia Maselli, R. Cross, M. Derrick, T. Tymieniecka, U. Kötz, R. L. Saunders, M. de Kamps, H. J. Kim, Giovanni Maccarrone, D. Hochman, C. Rembser, T. Ishii, F. J. Sciulli, T. Monteiro, S. Polenz, S. Schlenstedt, Amedeo Staiano, U. F. Katz, M. Pfeiffer, D. Filges, R. J. Tapper, D. Revel, Z. Duliński, J. Gilmore, Lucia Votano, Enrico Tassi, J. J. Whitmore, Giancarlo Susinno, Masami Chiba, R. Brugnera, S.H. An, P. J. Bussey, N. A. McCubbin, Marcella Capua, A. Meyer, K. Umemori, Mariusz Przybycien, D. Horstmann, N. H. Brook, V. L. Harris, V. K. Nadendla, M. Corradi, C. Nath, S. Yang, H. Heßling, J. F. Martin, I. Gialas, R. J. Nowak, F. Selonke, E. Hilger, Matthias Kasemann, V. A. Kuzmin, S. Campbell-Robson, H.J. Grabosch, J. P. Fernandez, Umberto Dosselli, Rosario Nania, Sung Keun Park, Cg Matthews, M. Roco, M. Rohde, Danuta Kisielewska, Marcel Vreeswijk, D Piccioni, N. Cartiglia, T. Tsurugai, O. Deppe, W. N. Murray, D. C. Bailey, J. Del Peso, M. De Giorgi, C. Youngman, A. M. Cooper-Sarkar, S. Dagan, D. Notz, G. Cases, A. Nigro, T. Massam, A.S. Proskuryakov, T. Yip, M. Inuzuka, R. van Woudenberg, A. Seiden, R. Stanek, W. Liu, K. Desler, R. J. Seifert, Leszek Adamczyk, I. A. Korzhavina, M. Khakzad, Janusz Chwastowski, M. L. Cardy, K. Homma, James Crittenden, Yu. A. Golubkov, M. Krzyżanowski, J. Ciborowski, M.I. Ferrero, M. St-Laurent, C. Coldewey, D.C. Williams, B. D. Burow, R. Loveless, ME Hayes, Luca Stanco, J.H. Vossebeld, E. Barberis, C.-P. Fagerstroem, A. Eskreys, A. T. Doyle, Y. Zamora Garcia, T. Voß, R. Ullmann, M. Nakao, P. Borzemski, R. G. Feild, M. Geerts, M. Posocco, T. W. Jones, A. N. Solomin, A. H. Walenta, DG Roff, L. Labarga, E. A. De Wolf, J. K. Sedgbeer, M. Eckert, L. Bellagamba, A.S. Wilson, L. Lamberti, Wouter Verkerke, C.R. Sampson, U. Mallik, Greg P Heath, J. R. Okrasinski, Jeffrey T. Rahn, L. M. Shcheglova, M. Grothe, P. Giusti, Gm Levman, B.Y. Oh, G. Zacek, G. L. Bashindzhagyan, A. Pesci, W.B. Schmidke, G. Drews, R. J. Teuscher, P. M. Patel, L. Heinz, J. A. Parsons, P. Joos, J. Stamm, A.F. Whitfield, S. W. Nam, B. A. Dolgoshein, Stefano Maria Mari, A. Quadt, D. S. Bailey, O. Schwarzer, Helen F Heath, J. Große-Knetter, V.A. Noyes, J.J. Engelen, Giuseppe Iacobucci, N. Pavel, J. R. Tickner, B. Foster, D. S. Waters, D. Krakauer, Jens Hartmann, G. Bruni, W. Hain, Z. Jing, M. Dardo, P.M. Kooijman, A. Dannemann, B. Lu, M. Brkic, J. Shulman, S. Ritz, D. S. Hanna, Vladimir Bashkirov, C. Amelung, M. L. Utley, N. Wulff, M. Riveline, M. Lancaster, J.T. Wu, Juan Terron, M. Kasprzak, K. Yamauchi, Y. Iga, J. Zając, H. Kowalski, A. Frey, M. Flasiński, N. Dyce, C. Voci, B. H. Y. Hung, J. K. Bienlein, Anselmo Margotti, L.W. Wiggers, E. Rulikowska-Zarebska, C. Li, P. Antonioli, A.I. van Sighem, K. Wick, G. Abbiendi, J.D. McFall, Marco Schioppa, G. Grzelak, T. C. Bacon, D. Hasell, G. D'Agostini, S. Mattingly, D. Schramm, C. A. Heusch, Luisa Cifarelli, L. K. Gladilin, Neville Harnew, D. Mikunas, G. Howell, J. Bulmahn, J. I. Fleck, D. Lüke, A. Polini, P.F. Ermolov, P. Bruni, P. G. Pelfer, T.P. Shah, Mark Sutton, T. Doeker, G. Briskin, Q. Zhu, S. M. Wang, D. H. Saxon, Costas Foudas, L.W. Mo, J. A. Zakrzewski, D. Westphal, F. Zuin, T. Y. Ling, S. Kartik, L. Lindemann, S. De Pasquale, M.C.K. Mattingly, U. Karshon, L. S. Durkin, E. Lohrmann, D. Zer-Zion, C. Glasman, P. Göttlicher, R. Hamatsu, Luis Hervas, I. Suzuki, S. Mine, D. Boscherini, R. Yoshida, J. Puga, Robert Klanner, A. Vaiciulis, R. S. Orr, A. Caldwell, G. Castellini, William S. Lockman, Michele Arneodo, H. F.W. Sadrozinski, J.S.T. Ng, Y. Eisenberg, D.J. Gilkinson, R. Walczak, J. M. Pawlak, P. B. Straub, Kenneth Long, R. Deffner, M. Adamus, A. Bornheim, K. Heinloth, A. Garfagnini, G. Bari, Giuseppe Barbagli, A. Ladage, J. Roldán, Hao Zhang, S. Magill, W. Schulz, G. Marini, Francois Corriveau, M. Van Hook, A. Kotański, K. Muchorowski, B. Bednarek, Np Zotov, I. H. Park, Wolfram Dietrich Zeuner, A.K. Wróblewski, A. Bamberger, Ben Bylsma, J. Milewski, O. Yu. Lukina, G. Sartorelli, R. Wedemeyer, M. Przybycien, B. J. Ko, H. Hartmann, L.A.T. Bauerdick, Giuseppe Levi, F. Zetsche, A. A. Savin, L. Suszycki, K. Jelen, S. Eisenhardt, Roberto Carlin, W.R. Frisken, Sridhara Dasu, D. Chapin, Halina Abramowicz, A. Bertolin, U. Schneekloth, J. F. de Trocóniz, I. Butterworth, F. Dal Corso, L. Zawiejski, Roberto Cirio, A. Cassidy, W.F. Badgett, Ta Romanowski, B. Musgrave, E. Paul, A. Stifutkin, F. F. Wilson, Jonathan Butterworth, B. Löhr, R. L. Talaga, S. Kitamura, Ada Solano, S. Limentani, M. Z. Wang, S. Bhadra, M. Zachara, Shoichi Yamada, R.C.E. Devenish, G. Laurenti, L. Iannotti, A. Prinias, Elisabetta Gallo, W. Koch, H. Beier, Tadeusz Kowalski, G. Poelz, Lutz Feld, J.T. Bromley, W. Metcalf, U. Holm, D. Acosta, Dg Stairs, Krzysztof Piotrzkowski, D. Sideris, D. B. Miller, Jose Repond, K. Ohrenberg, J. Gajewski, W. H. Smith, Mário Costa, G. H. Cho, J. Labs, F.S. Chlebana, M. Basile, T. Haas, V. D. Kobrin, T. Dubbs, J. Biltzinger, P. Cloth, R. Ayad, J. Breitweg, J. M. Hernandez, G. Cara Romeo, N. Brümmer, Simon George, Tachishige Hirose, M. Kuze, T. Matsushita, L. Wai, and R. Stroili
Subjects: Nuclear physics, Physics, Particle physics, Physics and Astronomy (miscellaneous), Rapidity, Center of mass, HERA, Zeus (malware), Energy (signal processing), Boson, Bar (unit)
Abstract: Deep inelastic charged-current reactions have been studied ine+p ande−p collisions at a center of mass energy of about 300GeV in the kinematic regionQ2>200GeV2 andx>0.006 using the ZEUS detector at HERA. The integrated cross sections forQ2>200GeV2 are found to be $\sigma _{e^ + p \to \bar \nu X} = 30.3_{ - 4.2 - 2.6}^{ + 5.5 + 1.6} pb$ and $\sigma _{e^ - p \to \nu X} = 54.7_{ - 9.8 - 3.4}^{ + 15.9 + 2.8} pb$. Differential cross sections have been measured as functions of the variablesx, y andQ2. From the measured differential cross sectionsdσ/dQ2, theW boson mass is determined to be $M_W = 79_{ - 7 - 4}^{ + 8 + 4} GeV$. Measured jet rates and transverse energy profiles agree with model predictions. A search for charged-current interactions with a large rapidity gap yielded one candidate event, corresponding to a cross section of $\sigma _{e^ + p \to \bar \nu X} (Q^2 > 200 GeV^2 ; \eta _{\max }< 2.5) = 0.8_{ - 0.7}^{ + 1.8} \pm 0.1 pb$
Published: 1996
Full Text: View/download PDF

3. Measurement of elasticρ 0 photoproduction at HERA

Author: D.D. Reeder, A. Bertolin, B. Diekmann, M. Wodarczyk, M. Lancaster, J.T. Wu, J. Zając, J. F. de Trocóniz, L. Zawiejski, Roberto Cirio, S.H. An, D. Mikunas, H.-P. Jakob, P. Morawitz, Rosario Nania, Sung Keun Park, R. L. Saunders, B. Musgrave, M. St.Laurent, G. Briskin, P. B. Kaziewicz, D. Krakauer, L. Lamberti, Simon George, Detlef Filges, Q. Zhu, R. Brugnera, P.M. Kooijman, Miguel Molina Martínez, H. Uijterwaal, E. Gallo, M. Roco, E. McCliment, V. A. Kuzmin, D. C. Bailey, Tachishige Hirose, M.C.K. Mattingly, L. S. Durkin, A. Dannemann, A. Stifutkin, M. De Giorgi, M. L. Utley, J. Shulman, T. Tsurugai, Aleksander Filip Żarnecki, Silvia Maselli, R. Hamatsu, A. Seiden, J. Puga, B. Surrow, Gm Levman, Giuseppe Barbagli, J. Bulmahn, D. S. Waters, Juan Terron, M. Kasprzak, M. Kuze, E. Rulikowska-Zarebska, J. I. Fleck, Y. Nagasawa, R. S. Orr, G. Zech, M. Flasiński, Vladimir Bashkirov, S.S. Wilson, A. Nigro, P. B. Straub, Kenneth Long, K. Yamauchi, S. Mengel, J. Mainusch, A. Eskreys, A. T. Doyle, A. Byrne, J. A. Zakrzewski, B. Bargende, L. Wai, B. Behrens, D. Horstmann, A. Dake, N. H. Brook, K. Wick, A. Prinias, L. Labarga, Wouter Verkerke, G. Bari, C.J.S. Morgado, M. Adamus, G. Marini, V. L. Harris, Michele Arneodo, D. C. Williams, R. Stroili, L. M. Shcheglova, T.L. Short, B. A. Dolgoshein, N. Bruemmer, Cg Matthews, M. de Kamps, H. J. Kim, Giovanni Maccarrone, S. Schlenstedt, P. J. Bussey, Giovanna Bruni, M. Van Hook, B. Bednarek, R. Yoshida, Np Zotov, Wolfram Dietrich Zeuner, A.K. Wróblewski, A. Bamberger, Avto Kharchilava, W. Schott, Cd Catterall, W. Koch, M. Eckert, L. Bellagamba, A.F. Whitfield, S. W. Nam, L. Köpke, C. Fordham, R. Loveless, Giuseppe Iacobucci, M. Rohde, A. M. Cooper-Sarkar, S. Dagan, M. Khakzad, M. L. Cardy, Roberto Sacchi, J.J. Engelen, J. M. Pawlak, A. Garfagnini, N. Pavel, I. Suzuki, William S. Lockman, J. F. Martin, Jose Repond, K. Ohrenberg, F. Zetsche, H. Beier, D. J. P. Norman, K. Honscheid, Aharon Levy, Y. Nakamitsu, Katsuo Tokushuku, T. Yip, F. J. Sciulli, I. H. Park, G. Grzelak, H.G.J.M. Tiecke, F. Benard, Roberto Carlin, Yu. A. Golubkov, E. Paul, M. Geerts, K. Blankenship, C.R. Sampson, P. Giusti, G. Zacek, G. Drews, J. A. Parsons, J. N. Lim, Cristiana Peroni, R. Sinkus, A. Freidhof, R. J. Tapper, G. F. Susinno, R. J. Cashmore, A. A. Savin, M. Derrick, M. Posocco, Geoffrey Smith, S. Ritz, D. S. Hanna, Anselmo Margotti, L.W. Wiggers, T. Tymieniecka, L. Suszycki, Jeffrey T. Rahn, Umberto Dosselli, P. M. Patel, Janusz Chwastowski, J. A. O'Mara, A. Bernstein, Y. Zamora Garcia, T. Voß, C. Youngman, V.A. Noyes, Tadeusz Kowalski, D. Acosta, S. Nickel, D. B. Miller, B. D. Burow, Ben Bylsma, J. Milewski, W.N. Murray, G. Anzivino, W. H. Smith, Mário Costa, H. Hartmann, Dg Stairs, U. Kötz, T. C. Bacon, J.B. Lane, J. Mollen, G. Poelz, Masashi Hazumi, E. A. De Wolf, J. Gajewski, A. Frey, M. Nakao, P. Borzemski, Giuseppe Levi, Gy. Wolf, Rr Rau, K. Jelen, J. R. Tickner, J. Ciborowski, S. Polenz, C. Rembser, Marcel Vreeswijk, R. Ullmann, P. Nylander, F.S. Chlebana, N. A. McCubbin, K. K. Joo, V. K. Nadendla, Masami Chiba, Klaus Kurt Desch, James Crittenden, O. Mańczak, T.P. Shah, S. M. Wang, D. H. Saxon, R. J. Nowak, M. Grothe, F. Selonke, E. Hilger, W.R. Frisken, J. Labs, G. F. Hartner, Ulf Behrens, Federico Cindolo, W. Bogusz, H. Kowalski, J. P. Fernandez, M. Dardo, C. Coldewey, Lutz Feld, M. Basile, A. B. Meyer, T. Haas, V. D. Kobrin, T. Dubbs, Samuel Silverstein, A.S. Wilson, Antonino Zichichi, P. Göttlicher, E. Stiliaris, D. Lüke, J. Del Peso, J. Biltzinger, A. Polini, K. Prytz, U. Schneekloth, W. Metcalf, M. Krzyżanowski, I. A. Korzhavina, S. De Pasquale, R. Ayad, I. Butterworth, M. H. Suh, U. Holm, B. Lu, L.E. Sinclair, D. Westphal, L. Hagge, Marco Schioppa, R. J. Seifert, P. G. Pelfer, Sridhara Dasu, B.Y. Oh, U. Karshon, A.S. Proskuryakov, R. Seidlein, Stefano Maria Mari, G. Cara Romeo, T. Ishii, K. Homma, Luis Hervas, D. Boscherini, R. van Woudenberg, A. Quadt, J. M. Hernandez, M. Zachara, Krzysztof Piotrzkowski, Ta Romanowski, G. Castellini, Shoichi Yamada, Fernando Barreiro, C. Li, J.S.T. Ng, R.C.E. Devenish, B. Y. H. Hung, F. Dal Corso, Halina Abramowicz, T. Hasegawa, H. F.W. Sadrozinski, A. Leich, W.F. Badgett, F. F. Wilson, M. Chiarini, G. Cases, Mauro Morandin, Danuta Kisielewska, G. Laurenti, Debades Bandyopadhyay, T. Massam, L. W. Hung, Jonathan Butterworth, T. J. Llewellyn, I. Ali, D. S. Bailey, D. Schramm, O. Schwarzer, S. M. Hong, Helen F Heath, R. L. Talaga, E. Tassi, Matthias Kasemann, I. Gialas, Jens Hartmann, L. Iannotti, K. M. Furutani, E. Lohrmann, D. Revel, Mariusz Przybycien, D. Notz, M. Corradi, S. Yang, J. Schroeder, A. H. Walenta, S. Campbell-Robson, R.S. Gilmore, W. Schulz, H.J. Grabosch, E. Barberis, J. K. Bienlein, O. Deppe, A. N. Solomin, S. H. Yon, U. Mallik, T. W. Jones, Anna Goussiou, Leszek Adamczyk, Yasunori Yamazaki, G. L. Bashindzhagyan, B. Gutjahr, Greg P Heath, John Hart, W.B. Schmidke, R. J. Teuscher, M.I. Ferrero, J. Große-Knetter, Douglas Gingrich, R. G. Feild, R. R. McNeil, K. Charchuła, A. Bruni, M. Löwe, S. Kartik, J.D. McFall, K. Muchorowski, R. Wedemeyer, J. J. Whitmore, Francois Corriveau, C. A. Heusch, J.F. Zhou, P.F. Ermolov, W. Hain, A. Kotański, P. Bruni, Costas Foudas, L.W. Mo, A. Caldwell, Christian Nemoz, L.A.T. Bauerdick, M.A.J. Botje, D. Zer-Zion, K.W. McLean, Ricardo Graciani, Y. Iga, A. Ladage, S. Söldner-Rembold, C. P. Fagerstroem, N. Dyce, Amedeo Staiano, O. Yu. Lukina, U. F. Katz, M. Pfeiffer, P. Cloth, R. Imlay, Ada Solano, C. Voci, S. Limentani, S. Magill, T. Doeker, M. Z. Wang, S. Bhadra, J. Gilmore, T. Timellini, A. Cassidy, R. Stanek, E. Badura, M. Nakahata, Luca Stanco, J. K. Sedgbeer, T. Neumann, B. Löhr, K. Desler, S. Kitamura, Thomas Trefzger, K.F. Johnson, Hao Zhang, Andrea Contin, A. Kruse, T. Monteiro, S. Eisenhardt, Marcella Capua, N. Cartiglia, C. Glasman, S. Mine, A. Bornheim, F. Palmonari, P. Joos, J. Stamm, B. Foster, Luisa Cifarelli, L. K. Gladilin, Neville Harnew, Y. Eisenberg, D.J. Gilkinson, R. Walczak, K. Heinloth, J. Roldán, G. Sartorelli, M. Brkic, N. Wulff, D. Hasell, G. D'Agostini, T. Y. Ling, L. Lindemann, Giovanni Abbiendi, Robert Klanner, A. Vaiciulis, Lucia Votano, C. Nath, and H. Heßling
Subjects: Nuclear physics, Physics, Cross section (physics), ZEUS (particle detector), Pion, Physics and Astronomy (miscellaneous), Proton, Vertex (curve), High Energy Physics::Experiment, Invariant mass, HERA, Nuclear Experiment, Helicity
Abstract: Elasticρ0 photoproduction has been measured using the ZEUS detector at HERA. Untagged photoproduction events fromep interactions were used to measure the reactionγp→ρ0p(ρ0)→π+π−) at photon-proton centre-of-mass energies between 60 and 80 GeV and |t
Published: 1995
Full Text: View/download PDF

4. Measurement of the proton structure functionF 2 at lowx and lowQ 2 at HERA

Author: D. Krakauer, M. L. Utley, J. Mollen, J. I. Fleck, Y. Nagasawa, P. Nylander, K. K. Joo, O. Mańczak, G. F. Hartner, R. Yoshida, J. A. Zakrzewski, Thomas Trefzger, F. J. Sciulli, K.F. Johnson, P. Bruni, Costas Foudas, A. M. Cooper-Sarkar, S. Dagan, M. Khakzad, M. L. Cardy, K. Honscheid, Yu. A. Golubkov, Vladimir Bashkirov, H. Tiecke, M. Posocco, Geoffrey Smith, L.W. Mo, Andrea Contin, C. Händel-Pikielny, J. F. Martin, N. Bruemmer, Christian Nemoz, A. Caldwell, A. Frey, F. Selonke, L. Köpke, Ulf Behrens, Federico Cindolo, W. Bogusz, A. Cassidy, Y. Iga, N. Dyce, J. Ciborowski, A. Kruse, D. Schramm, C. A. Heusch, E. Hilger, G. Grzelak, R. Ullmann, C. Voci, T. Monteiro, J. M. Pawlak, T. C. Bacon, T. Yip, Mariusz Przybycien, M. Corradi, A. Bernstein, Y. Zamora Garcia, T. Voß, M. Nakahata, Cg Matthews, M.A.J. Botje, Marcella Capua, W. Metcalf, U. Holm, A. Garfagnini, Fernando Barreiro, Mauro Morandin, Hao Zhang, M. Dardo, C. Coldewey, S. Yang, Jens Hartmann, P. Cloth, N. Pavel, I. Suzuki, William S. Lockman, K.W. McLean, S. Nickel, D. B. Miller, J. Gajewski, A. Ladage, Ricardo Graciani, S. Söldner-Rembold, K. Prytz, N. Cartiglia, K. Muchorowski, P. Kooijman, L. W. Hung, T. Neumann, Lucia Votano, T.P. Shah, E. Lohrmann, B. Löhr, C. Nath, C. P. Fagerstroem, H. Heßling, F. Palmonari, M. Krzyżanowski, W. N. Murray, S. M. Wang, S. De Pasquale, D. H. Saxon, I. H. Park, O. Yu. Lukina, Ben Bylsma, D. Lüke, A. Polini, S. Campbell-Robson, S. Kitamura, Amedeo Staiano, U. F. Katz, R. Wedemeyer, M. Basile, Rosario Nania, Sung Keun Park, J. K. Bienlein, T. Doeker, J. Milewski, S. Eisenhardt, Y. Eisenberg, H.J. Grabosch, S. Kartik, P. Göttlicher, J. Gilmore, M. Pfeiffer, T. Haas, V. D. Kobrin, T. Dubbs, Antonino Zichichi, ME Hayes, E. Tassi, A. Nigro, D.J. Gilkinson, B. Lu, S. W. Nam, R. Ayad, R. Walczak, J. Biltzinger, B.Y. Oh, M. H. Suh, M. Zachara, Krzysztof Piotrzkowski, K. Heinloth, Giuseppe Barbagli, D. Filges, J. Roldán, M. Eckert, L. Bellagamba, Shoichi Yamada, R.C.E. Devenish, Francois Corriveau, H. Hartmann, E. McCliment, D. Revel, G. Cara Romeo, A. Dannemann, H.-P. Jakob, P. Joos, R. L. Saunders, O. Deppe, J. Stamm, A.F. Whitfield, A. Kotański, A. Meyer, A. Seiden, G. Laurenti, L.A.T. Bauerdick, B. Foster, M. Lancaster, J. M. Hernandez, R. Brugnera, C. Li, G. Sartorelli, J.T. Wu, J.R. Okrasiński, J. Bulmahn, J. Zając, Yasunori Yamazaki, G. Cases, D. C. Bailey, B. Gutjahr, V. A. Kuzmin, R. Stanek, M. De Giorgi, C. Youngman, A. Eskreys, A. T. Doyle, L. Labarga, Wouter Verkerke, R. R. McNeil, E. Badura, D. Mikunas, W. N. Cottingham, C. Fordham, Luisa Cifarelli, L. K. Gladilin, Neville Harnew, P. Morawitz, B. Y. H. Hung, Sridhara Dasu, Marcel Vreeswijk, T.L. Short, D Piccioni, B. A. Dolgoshein, John Hart, W. Schulz, Luca Stanco, K. Desler, L. Iannotti, Ada Solano, Gm Levman, S. Ritz, D. S. Hanna, Halina Abramowicz, D. C. Williams, D. S. Waters, S. Limentani, J. Del Peso, Aleksander Filip Żarnecki, Silvia Maselli, G. Briskin, E. Rulikowska-Zarcebska, Roberto Carlin, M. de Kamps, K. Charchuła, K. Yamauchi, Q. Zhu, M. Brkic, L.E. Sinclair, K. Homma, H. J. Kim, C. Glasman, N. Wulff, Cristiana Peroni, R. J. Cashmore, Roberto Sacchi, H. Kowalski, M. Z. Wang, D. Hasell, G. D'Agostini, Giovanni Maccarrone, J. K. Sedgbeer, Anselmo Margotti, Simon George, S. Mine, S. Schlenstedt, S. Bhadra, A. Bruni, T. Y. Ling, L. Lindemann, L.W. Wiggers, P. J. Bussey, M. Löwe, Tachishige Hirose, J.D. McFall, D. Horstmann, R. Timellini, A. Dake, N. H. Brook, V. L. Harris, B. D. Burow, Giovanni Abbiendi, Robert Klanner, A. Vaiciulis, G. Bruni, M. Derrick, A. Prinias, Elisabetta Gallo, T. Tymieniecka, A. Bornheim, E. Barberis, J. A. O'Mara, P.F. Ermolov, Jose Repond, G. Anzivino, K. Ohrenberg, Giuseppe Levi, W. Koch, M. Rohde, Danuta Kisielewska, A. N. Solomin, U. Kötz, U. Mallik, Aharon Levy, D. Westphal, P. Giusti, J. T. Rahn, M. Nakao, P. Borzemski, M. Kuze, T. Massam, J. N. Lim, A. Bertolin, Greg P Heath, K. Jelen, J. Engelen, G. Zacek, G. Drews, J. A. Parsons, U. Karshon, H. Beier, A.S. Wilson, J. J. Whitmore, W. Hain, R. Sinkus, Luis Hervas, D. Zer-Zion, J. F. de Trocóniz, L. Zawiejski, W.R. Frisken, I. Ali, D. Boscherini, Tadeusz Kowalski, V. K. Nadendla, R. J. Nowak, W. H. Smith, J. Große-Knetter, Roberto Cirio, D. S. Bailey, O. Schwarzer, Helen F Heath, G. Poelz, J.F. Zhou, G. Castellini, L. Wai, Mário Costa, A. H. Walenta, DG Roff, Lutz Feld, M.C.K. Mattingly, L. S. Durkin, Douglas Gingrich, Giancarlo Susinno, B. Musgrave, M. St.Laurent, J.S.T. Ng, R. Stroili, R. Hamatsu, R. Imlay, K. Wick, E. Paul, J. Puga, F.S. Chlebana, U. Schneekloth, A. Stifutkin, I. Gialas, I. Butterworth, S. Magill, M. Adamus, J. Schroeder, S. Polenz, Ta Romanowski, G. Marini, Np Zotov, Wolfram Dietrich Zeuner, A.K. Wróblewski, A. Bamberger, Masami Chiba, Klaus Kurt Desch, Matthias Kasemann, K. M. Furutani, F. F. Wilson, M. Chiarini, Leszek Adamczyk, Jonathan Butterworth, J. P. Fernandez, D. Notz, I. A. Korzhavina, M.I. Ferrero, S. H. Yon, D. Acosta, T. W. Jones, Anna Goussiou, Dg Stairs, G. L. Bashindzhagyan, W.B. Schmidke, R. J. Teuscher, R. G. Feild, J. Labs, A. Freidhof, James Crittenden, M. Grothe, L. Heinz, R. S. Orr, P. B. Straub, Kenneth Long, F. Dal Corso, Marco Schioppa, P. G. Pelfer, B. Behrens, G. Bari, R. Seidlein, T. Hasegawa, M. Van Hook, B. Bednarek, A. Leich, W.F. Badgett, H. F.W. Sadrozinski, F. Zetsche, Y. Nakamitsu, Katsuo Tokushuku, R. J. Tapper, J. Shulman, Umberto Dosselli, Debades Bandyopadhyay, Janusz Chwastowski, E. A. De Wolf, J. R. Tickner, D.D. Reeder, Juan Terron, M. Kasprzak, B. Diekmann, G. Zech, M. Flasiński, M. Wodarczyk, S. M. Hong, Masashi Hazumi, R. L. Talaga, C. Rembser, N. A. McCubbin, Samuel Silverstein, E. Stiliaris, L. Hagge, P. B. Kaziewicz, T. Ishii, R. J. Seifert, L. Lamberti, Stefano Maria Mari, A. Quadt, H. Uijterwaal, L. M. Shcheglova, A.S. Proskuryakov, C.J.S. Morgado, Michele Arneodo, R. van Woudenberg, F. Benard, M. Martinez, A. A. Savin, L. Suszycki, Giuseppe Iacobucci, R. Loveless, M. Geerts, K. Blankenship, C.R. Sampson, J.B. Lane, P. M. Patel, Gy. Wolf, Rr Rau, B. Surrow, S.H. An, V.A. Noyes, M. Roco, T. Tsurugai, S. Mengel, J. Mainusch, A. Byrne, Avto Kharchilava, W. Schott, and Cd Catterall
Subjects: Nuclear physics, Physics, Range (particle radiation), Physics and Astronomy (miscellaneous), Proton, law, Structure (category theory), Perturbative QCD, HERA, Collider, Deep inelastic scattering, law.invention, Positron energy
Abstract: We report on a measurement of the proton structure function F 2 in the range 3.5×10-5≤x≤4×10-3 and 1.5 GeV2≤Q 2≤15GeV2 at the ep collider HERA operating at a centre-of-mass energy of √s=300GeV. The rise of F 2 with decreasing x observed in the previous HERA measurements persists in this lower x and Q 2 range. The Q 2 evolution of F 2, even at the lowest Q 2 and x measured, is consistent with perturbative QCD. © 1996 Springer-Verlag.
Published: 1995
Full Text: View/download PDF

5. Measurement of Charged and Neutral Currente−pDeep Inelastic Scattering Cross Sections at HighQ2

Author: M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. Repond, R. Stanek, R. L. Talaga, H. Zhang, R. Ayad, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, P. Bruni, G. Cara Romeo, G. Castellini, M. Chiarini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi, A. Margotti, T. Massam, R. Nania, C. Nemoz, F. Palmonari, A. Polini, G. Sartorelli, R. Timellini, Y. Zamora Garcia, A. Zichichi, A. Bargende, J. Crittenden, K. Desch, B. Diekmann, T. Doeker, M. Eckert, L. Feld, A. Frey, M. Geerts, G. Geitz, M. Grothe, T. Haas, H. Hartmann, D. Haun, K. Heinloth, E. Hilger, H.-P. Jakob, U. F. Katz, S. M. Mari, A. Mass, S. Mengel, J. Mollen, E. Paul, Ch. Rembser, R. Schattevoy, D. Schramm, J. Stamm, R. Wedemeyer, S. Campbell-Robson, A. Cassidy, N. Dyce, B. Foster, S. George, R. Gilmore, G. P. Heath, H. F. Heath, T. J. Llewellyn, C. J. S. Morgado, D. J. P. Norman, J. A. O'Mara, R. J. Tapper, S. S. Wilson, R. Yoshida, R. R. Rau, M. Arneodo, L. Iannotti, M. Schioppa, G. Susinno, A. Bernstein, A. Caldwell, N. Cartiglia, J. A. Parsons, S. Ritz, F. Sciulli, P. B. Straub, L. Wai, S. Yang, Q. Zhu, P. Borzemski, J. Chwastowski, A. Eskreys, K. Piotrzkowski, M. Zachara, L. Zawiejski, L. Adamczyk, B. Bednarek, K. Jeleń, D. Kisielewska, T. Kowalski, E. Rulikowska-Zarȩbska, L. Suszycki, J. Zaja̧c, A. Kotański, M. Przybycień, L. A. T. Bauerdick, U. Behrens, H. Beier, J. K. Bienlein, C. Coldewey, O. Deppe, K. Desler, G. Drews, M. Flasiński, D. J. Gilkinson, C. Glasman, P. Göttlicher, J. Grosse-Knetter, B. Gutjahr, W. Hain, D. Hasell, H. Hessling, H. Hultschig, Y. Iga, P. Joos, M. Kasemann, R. Klanner, W. Koch, L. Köpke, U. Kötz, H. Kowalski, J. Labs, A. Ladage, B. Löhr, M. Löwe, D. Lüke, O. Mańczak, J. S. T. Ng, S. Nickel, D. Notz, K. Ohrenberg, M. Roco, M. Rohde, J. Roldán, U. Schneekloth, W. Schulz, F. Selonke, E. Stiliaris, B. Surrow, T. Voss, D. Westphal, G. Wolf, C. Youngman, J. F. Zhou, H. J. Grabosch, A. Kharchilava, A. Leich, M. Mattingly, A. Meyer, S. Schlenstedt, N. Wulff, G. Barbagli, P. Pelfer, G. Anzivino, G. Maccarrone, S. De Pasquale, L. Votano, A. Bamberger, S. Eisenhardt, A. Freidhof, S. Söldner-Rembold, J. Schroeder, T. Trefzger, N. H. Brook, P. J. Bussey, A. T. Doyle, J. I. Fleck, D. H. Saxon, M. L. Utley, A. S. Wilson, A. Dannemann, U. Holm, D. Horstmann, T. Neumann, R. Sinkus, K. Wick, E. Badura, B. D. Burow, L. Hagge, E. Lohrmann, J. Mainusch, J. Milewski, M. Nakahata, N. Pavel, G. Poelz, W. Schott, F. Zetsche, T. C. Bacon, I. Butterworth, E. Gallo, V. L. Harris, B. Y. H. Hung, K. R. Long, D. B. Miller, P. P. O. Morawitz, A. Prinias, J. K. Sedgbeer, A. F. Whitfield, U. Mallik, E. McCliment, M. Z. Wang, S. M. Wang, J. T. Wu, Y. Zhang, P. Cloth, D. Filges, S. H. An, S. M. Hong, S. W. Nam, S. K. Park, M. H. Suh, S. H. Yon, R. Imlay, S. Kartik, H.-J. Kim, R. R. McNeil, W. Metcalf, V. K. Nadendla, F. Barreiro, G. Cases, R. Graciani, J. M. Hernández, L. Hervás, L. Labarga, J. del Peso, J. Puga, J. Terron, J. F. de Trocóniz, G. R. Smith, F. Corriveau, D. S. Hanna, J. Hartmann, L. W. Hung, J. N. Lim, C. G. Matthews, P. M. Patel, L. E. Sinclair, D. G. Stairs, M. St. Laurent, R. Ullmann, G. Zacek, V. Bashkirov, B. A. Dolgoshein, A. Stifutkin, G. L. Bashindzhagyan, P. F. Ermolov, L. K. Gladilin, Y. A. Golubkov, V. D. Kobrin, V. A. Kuzmin, A. S. Proskuryakov, A. A. Savin, L. M. Shcheglova, A. N. Solomin, N. P. Zotov, M. Botje, F. Chlebana, A. Dake, J. Engelen, M. de Kamps, P. Kooijman, A. Kruse, H. Tiecke, W. Verkerke, M. Vreeswijk, L. Wiggers, E. de Wolf, R. van Woudenberg, D. Acosta, B. Bylsma, L. S. Durkin, K. Honscheid, C. Li, T. Y. Ling, K. W. McLean, W. N. Murray, I. H. Park, T. A. Romanowski, R. Seidlein, D. S. Bailey, G. A. Blair, A. Byrne, R. J. Cashmore, A. M. Cooper-Sarkar, D. Daniels, R. C. E. Devenish, N. Harnew, M. Lancaster, P. E. Luffman, L. Lindemann, J. D. McFall, C. Nath, V. A. Noyes, A. Quadt, H. Uijterwaal, R. Walczak, F. F. Wilson, T. Yip, G. Abbiendi, A. Bertolin, R. Brugnera, R. Carlin, F. Dal Corso, M. De Giorgi, U. Dosselli, S. Limentani, M. Morandin, M. Posocco, L. Stanco, R. Stroili, C. Voci, J. Bulmahn, J. M. Butterworth, R. G. Feild, B. Y. Oh, J. J. Whitmore, G. D'Agostini, G. Marini, A. Nigro, E. Tassi, J. C. Hart, N. A. McCubbin, K. Prytz, T. P. Shah, T. L. Short, E. Barberis, T. Dubbs, C. Heusch, M. Van Hook, B. Hubbard, W. Lockman, J. T. Rahn, H. F.-W. Sadrozinski, A. Seiden, J. Biltzinger, O. Schwarzer, R. J. Seifert, A. H. Walenta, G. Zech, H. Abramowicz, G. Briskin, S. Dagan, A. Levy, T. Hasegawa, M. Hazumi, T. Ishii, M. Kuze, S. Mine, Y. Nagasawa, M. Nakao, I. Suzuki, K. Tokushuku, S. Yamada, Y. Yamazaki, M. Chiba, R. Hamatsu, T. Hirose, K. Homma, S. Kitamura, Y. Nakamitsu, K. Yamauchi, R. Cirio, M. Costa, M. I. Ferrero, L. Lamberti, S. Maselli, C. Peroni, R. Sacchi, A. Solano, A. Staiano, M. Dardo, D. C. Bailey, D. Bandyopadhyay, F. Benard, M. Brkic, M. B. Crombie, D. M. Gingrich, G. F. Hartner, K. K. Joo, G. M. Levman, J. F. Martin, R. S. Orr, C. R. Sampson, R. J. Teuscher, C. D. Catterall, T. W. Jones, P. B. Kaziewicz, J. B. Lane, R. L. Saunders, J. Shulman, K. Blankenship, J. Kochocki, B. Lu, L. W. Mo, W. Bogusz, K. Charchuła, J. Ciborowski, J. Gajewski, G. Grzelak, M. Kasprzak, M. Krzyżanowski, K. Muchorowski, R. J. Nowak, J. M. Pawlak, T. Tymieniecka, A. K. Wróblewski, J. A. Zakrzewski, A. F. Żarnecki, M. Adamus, Y. Eisenberg, U. Karshon, D. Revel, D. Zer-Zion, I. Ali, W. F. Badgett, B. Behrens, S. Dasu, C. Fordham, C. Foudas, A. Goussiou, R. J. Loveless, D. D. Reeder, S. Silverstein, W. H. Smith, A. Vaiciulis, M. Wodarczyk, T. Tsurugai, S. Bhadra, M. L. Cardy, C.-P. Fagerstroem, W. R. Frisken, K. M. Furutani, M. Khakzad, and W.B. Schmidke
Subjects: Quantum chromodynamics, Physics, Particle physics, Neutral current, 010308 nuclear & particles physics, Scattering, Momentum transfer, General Physics and Astronomy, HERA, Deep inelastic scattering, 01 natural sciences, 7. Clean energy, Nuclear physics, Cross section (physics), 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Boson
Abstract: Deep inelastic $e~-p$ scattering has been studied in both the charged-current (CC) and neutral-current (NC) reactions at momentum transfers squared, $Q~2$, between 400 GeV$~2$ and the kinematic limit of 87500 GeV$~2$ using the ZEUS detector at the HERA $ep$ collider. The CC and NC total cross sections, the NC to CC cross section ratio, and the differential cross sections, $ d\sigma/dQ~2 $, are presented. For $Q~2 \simeq M_W~2$, where $M_W$ is the mass of the $W$ boson, the CC and NC cross sections have comparable magnitudes, demonstrating the equal strengths of the weak and electromagnetic interactions at high $Q~2$. The $Q~2$ dependence of the CC cross section determines the mass term in the CC propagator to be $M_{W} = 76 \pm 16 \pm 13$GeV.
Published: 1995
Full Text: View/download PDF

6. Observation of hard scattering in photoproduction events with a large rapidity gap at HERA

Author: M. Derrick, D. Krakauer, S. Magill, B. Musgrave, J. Repond, J. Schlereth, R. Stanek, R.L. Talaga, J. Thron, F. Arzarello, R. Ayad, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, P. Bruni, G. Cara Romeo, G. Castellini, M. Chiarini, L. Cifarelli, F. Cindolo, F. Ciralli, A. Contin, S. D'Auria, F. Frasconi, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi, A. Margotti, T. Massam, R. Nania, C. Nemoz, F. Palmonari, A. Polini, G. Sartorelli, R. Timellini, Y. Zamora Garcia, A. Zichichi, A. Bargende, J. Crittenden, K. Desch, B. Diekmann, T. Doeker, M. Eckert, L. Feld, A. Frey, M. Geerts, G. Geitz, M. Grothe, H. Hartmann, D. Haun, K. Heinloth, E. Hilger, H.-P. Jakob, U.F. Katz, S.M. Mari, A. Mass, S. Mengel, J. Mollen, E. Paul, Ch. Rembser, R. Schattevoy, D. Schramm, J. Stamm, R. Wedemeyer, S. Campbell-Robson, A. Cassidy, N. Dyce, B. Foster, S. George, R. Gilmore, G.P. Heath, H.F. Heath, T.J. Llewellyn, C.J.S. Morgado, D.J.P. Norman, J.A. O'Mara, R.J. Tapper, S.S. Wilson, R. Yoshida, R.R. Rau, M. Arneodo, L. Iannotti, M. Schioppa, G. Susinno, A. Bernstein, A. Caldwell, J.A. Parsons, S. Ritz, F. Sciulli, P.B. Straub, L. Wai, S. Yang, Q. Zhu, P. Borzemski, J. Chwastowski, A. Eskreys, K. Piotrzkowski, M. Zachara, L. Zawiejski, L. Adamczyk, B. Bednarek, K. Eskreys, K. Jeleń, D. Kisielewska, T. Kowalski, E. Rulikowska-Zarȩbska, L. Suszycki, J. Zaja̧c, A. Kotański, M. Przybycień, L.A.T. Bauerdick, U. Behrens, J.K. Bienlein, S. Böttcher, C. Coldewey, G. Drews, M. Flasiński, D.J. Gilkinson, P. Göttlicher, B. Gutjahr, T. Haas, W. Hain, D. Hasell, H. Heßling, H. Hultschig, Y. Iga, P. Joos, M. Kasemann, R. Klanner, W. Koch, L. Köpke, U. Kötz, H. Kowalski, W. Kröger, J. Krüger, J. Labs, A. Ladage, B. Löhr, M. Löwe, D. Lüke, O. Mańczak, J.S.T. Ng, S. Nickel, D. Notz, K. Ohrenberg, M. Roco, M. Rohde, J. Roldán, U. Schneekloth, W. Schulz, F. Selonke, E. Stiliaris, T. Voß, D. Westphal, G. Wolf, C. Youngman, H.J. Grabosch, A. Leich, A. Meyer, C. Rethfeldt, S. Schlenstedt, G. Barbagli, P. Pelfer, G. Anzivino, G. Maccarrone, S. De Pasquale, S. Qian, L. Votano, A. Bamberger, A. Freidhof, T. Poser, S. Söldner-Rembold, J. Schroeder, G. Theisen, T. Trefzger, N.H. Brook, P.J. Bussey, A.T. Doyle, I. Fleck, V.A. Jamieson, D.H. Saxon, M.L. Utley, A.S. Wilson, A. Dannemann, U. Holm, D. Horstmann, H. Kammerlocher, B. Krebs, T. Neumann, R. Sinkus, K. Wick, E. Badura, B.D. Burow, A. Fürtjes, L. Hagge, E. Lohrmann, J. Mainusch, J. Milewski, M. Nakahata, N. Pavel, G. Poelz, W. Schott, J. Terron, F. Zetsche, T.C. Bacon, R. Beuselinck, I. Butterworth, E. Gallo, V.L. Harris, B.H. Hung, K.R. Long, D.B. Miller, P.P.O. Morawitz, A. Prinias, J.K. Sedgbeer, A.F. Whitfield, U. Mallik, E. McCliment, M.Z. Wang, S.M. Wang, J.T. Wu, Y. Zhang, P. Cloth, D. Filges, S.H. An, S.M. Hong, S.W. Nam, S.K. Park, M.H. Suh, S.H. Yon, R. Imlay, S. Kartik, H.-J. Kim, R.R. McNeil, W. Metcalf, V.K. Nadendla, F. Barreiro, G. Cases, R. Graciani, J.M. Hernández, L. Hervás, L. Labarga, J. del Peso, J. Puga, J.F. de Trocóniz, G.R. Smith, F. Corriveau, D.S. Hanna, J. Hartmann, L.W. Hung, J.N. Lim, C.G. Matthews, P.M. Patel, L.E. Sinclair, D.G. Stairs, M.St. Laurent, R. Ullmann, G. Zacek, V. Bashkirov, B.A. Dolgoshein, A. Stifutkin, G.L. Bashindzhagyan, P.F. Ermolov, L.K. Gladilin, Y.A. Golubkov, V.D. Kobrin, V.A. Kuzmin, A.S. Proskuryakov, A.A. Savin, L.M. Shcheglova, A.N. Solomin, N.P. Zotov, S. Bentvelsen, M. Botje, F. Chlebana, A. Dake, J. Engelen, P. de Jong, M. de Kamps, P. Kooijman, A. Kruse, V. O'Dell, A. Tenner, H. Tiecke, W. Verkerke, M. Vreeswijk, L. Wiggers, E. de Wolf, R. van Woudenberg, D. Acosta, B. Bylsma, L.S. Durkin, K. Honscheid, C. Li, T.Y. Ling, K.W. McLean, W.N. Murray, I.H. Park, T.A. Romanowski, R. Seidlein, D.S. Bailey, G.A. Blair, A. Byrne, R.J. Cashmore, A.M. Cooper-Sarkar, D. Daniels, R.C.E. Devenish, N. Harnew, M. Lancaster, P.E. Luffman, L. Lindemann, J. McFall, C. Nath, A. Quadt, H. Uijterwaal, R. Walczak, F.F. Wilson, T. Yip, G. Abbiendi, A. Bertolin, R. Brugnera, R. Carlin, F. Dal Corso, M. De Giorgi, U. Dosselli, S. Limentani, M. Morandin, M. Posocco, L. Stanco, R. Stroili, C. Voci, J. Bulmahn, J.M. Butterworth, R.G. Feild, B.Y. Oh, J.J. Whitmore, G. D'Agostini, M. Iori, G. Marini, M. Mattioli, A. Nigro, E. Tassi, J.C. Hart, N.A. McCubbin, K. Prytz, T.P. Shah, T.L. Short, E. Barberis, N. Cartiglia, T. Dubbs, C. Heusch, M. Van Hook, B. Hubbard, W. Lockman, J.T. Rahn, H.F.-W. Sadrozinski, A. Seiden, J. Biltzinger, R.J. Seifert, A.H. Walenta, G. Zech, H. Abramowicz, G. Briskin, S. Dagan, A. Levy, T. Hasegawa, M. Hazumi, T. Ishii, M. Kuze, S. Mine, Y. Nagasawa, T. Nagira, M. Nakao, I. Suzuki, K. Tokushuku, S. Yamada, Y. Yamazaki, M. Chiba, R. Hamatsu, T. Hirose, K. Homma, S. Kitamura, S. Nagayama, Y. Nakamitsu, R. Cirio, M. Costa, M.I. Ferrero, L. Lamberti, S. Maselli, C. Peroni, R. Sacchi, A. Solano, A. Staiano, M. Dardo, D.C. Bailey, D. Bandyopadhyay, F. Benard, M. Brkic, M.B. Crombie, D.M. Gingrich, G.F. Hartner, K.K. Joo, G.M. Levman, J.F. Martin, R.S. Orr, C.R. Sampson, R.J. Teuscher, C.D. Catterall, T.W. Jones, P.B. Kaziewicz, J.B. Lane, R.L. Saunders, J. Shulman, K. Blankenship, J. Kochocki, B. Lu, L.W. Mo, W. Bogusz, K. Charchuła, J. Ciborowski, J. Gajewski, G. Grzelak, M. Kasprzak, M. Krzyżanowski, K. Muchorowski, R.J. Nowak, J.M. Pawlak, T. Tymieniecka, A.K. Wróblewski, J.A. Zakrzewski, A.F. Żarnecki, M. Adamus, Y. Eisenberg, C. Glasman, U. Karshon, D. Revel, A. Shapira, I. Ali, B. Behrens, S. Dasu, C. Fordham, C. Foudas, A. Goussiou, R.J. Loveless, D.D. Reeder, S. Silverstein, W.H. Smith, T. Tsurugai, S. Bhadra, W.R. Frisken, K.M. Furutani, and Zeus (IHEF, IoP, FNWI)
Subjects: Nuclear and High Energy Physics, Particle physics, Photon, Proton, Astrophysics::High Energy Astrophysical Phenomena, Hadron, FOS: Physical sciences, Astronomy & Astrophysics, DIFFRACTION, 01 natural sciences, High Energy Physics - Experiment, Physics, Particles & Fields, law.invention, COLLIDER, Nuclear physics, High Energy Physics - Experiment (hep-ex), 0202 Atomic, Molecular, Nuclear, Particle And Plasma Physics, DESIGN, law, 0103 physical sciences, Rapidity, CALORIMETER, Nuclear Experiment, 010306 general physics, Collider, DETECTOR, Physics, Research Groups and Centres\Physics\Low Temperature Physics, Science & Technology, ZEUS (particle detector), Faculty of Science\Physics, hep-ex, 010308 nuclear & particles physics, Scattering, ZEUS, diffractive scattering, HERA, photoproduction, Nuclear & Particles Physics, POMERON STRUCTURE, Physics, Nuclear, PHOTON, Physical Sciences, JETS, High Energy Physics::Experiment
Abstract: Events with a large rapidity gap and total transverse energy greater than 5 GeV have been observed in quasi-real photoproduction at HERA with the ZEUS detector. The distribution of these events as a function of the $\gamma p$ centre of mass energy is consistent with diffractive scattering. For total transverse energies above 12 GeV, the hadronic final states show predominantly a two-jet structure with each jet having a transverse energy greater than 4 GeV. For the two-jet events, little energy flow is found outside the jets. This observation is consistent with the hard scattering of a quasi-real photon with a colourless object in the proton., Comment: 19 pages, latex, 4 figures appended as uuencoded file
Published: 1995
Full Text: View/download PDF

7. Measurement of elastic $\phi$ photoproduction at HERA

Author: M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J.R. Okrasinski, J. Repond, R. Stanek, R.L. Talaga, H. Zhang, M.C.K. Mattingly, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, P. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi, A. Margotti, T. Massam, R. Nania, F. Palmonari, A. Polini, G. Sartorelli, Y. Zamora Garcia, A. Zichichi, A. Bornheim, J. Crittenden, T. Doeker, M. Eckert, L. Feld, A. Frey, M. Geerts, M. Grothe, H. Hartmann, K. Heinloth, L. Heinz, E. Hilger, H.-P. Jakob, U.F. Katz, S. Mengel, J. Mollen, E. Paul, M. Pfeiffer, Ch. Rembser, D. Schramm, J. Stamm, R. Wedemeyer, S. Campbell-Robson, A. Cassidy, W.N. Cottingham, N. Dyce, B. Foster, S. George, M.E. Hayes, G.P. Heath, H.F. Heath, D. Piccioni, D.G. Roff, R.J. Tapper, R. Yoshida, M. Arneodo, R. Ayad, M. Capua, A. Garfagnini, L. Iannotti, M. Schioppa, G. Susinno, A. Caldwell, N. Cartiglia, Z. Jing, W. Liu, J.A. Parsons, S. Ritz, F. Sciulli, P.B. Straub, L. Wai, S. Yang, Q. Zhu, P. Borzemski, J. Chwastowski, A. Eskreys, M. Zachara, L. Zawiejski, L. Adamczyk, B. Bednarek, K. Jeleń, D. Kisielewska, T. Kowalski, M. Przybycień, E. Rulikowska-Zarȩbska, L. Suszycki, J. Zaja̧c, A. Kotański, L.A.T. Bauerdick, U. Behrens, H. Beier, J.K. Bienlein, O. Deppe, K. Desler, G. Drews, M. Flasiński, D.J. Gilkinson, C. Glasman, P. Göttlicher, J. Große-Knetter, T. Haas, W. Hain, D. Hasell, H. Heßling, Y. Iga, K.F. Johnson, P. Joos, M. Kasemann, R. Klanner, W. Koch, U. Kötz, H. Kowalski, J. Labs, A. Ladage, B. Löhr, M. Löwe, D. Lüke, J. Mainusch, O. Mańczak, T. Monteiro, J.S.T. Ng, D. Notz, K. Ohrenberg, K. Piotrzkowski, M. Roco, M. Rohde, J. Roldán, U. Schneekloth, W. Schulz, F. Selonke, B. Surrow, T. Voß, D. Westphal, G. Wolf, C. Youngman, W. Zeuner, H.J. Grabosch, A. Kharchilava, S.M. Mari, A. Meyer, S. Schlenstedt, N. Wulff, G. Barbagli, E. Gallo, P. Pelfer, G. Maccarrone, S. De Pasquale, L. Votano, A. Bamberger, S. Eisenhardt, T. Trefzger, S. Wölfle, J.T. Bromley, N.H. Brook, P.J. Bussey, A.T. Doyle, D.H. Saxon, L.E. Sinclair, M.L. Utley, A.S. Wilson, A. Dannemann, U. Holm, D. Horstmann, R. Sinkus, K. Wick, B.D. Burow, L. Hagge, E. Lohrmann, J. Milewski, N. Pavel, G. Poelz, W. Schott, F. Zetsche, T.C. Bacon, N. Brümmer, I. Butterworth, V.L. Harris, G. Howell, B.H.Y. Hung, L. Lamberti, K.R. Long, D.B. Miller, A. Prinias, J.K. Sedgbeer, D. Sideris, A.F. Whitfield, U. Mallik, M.Z. Wang, S.M. Wang, J.T. Wu, P. Cloth, D. Filges, S.H. An, G.H. Cho, B.J. Ko, S.B. Lee, S.W. Nam, H.S. Park, S.K. Park, S. Kartik, H.-J. Kim, R.R. McNeil, W. Metcalf, V.K. Nadendla, F. Barreiro, G. Cases, J.P. Fernandez, R. Graciani, J.M. Hernández, L. Hervás, L. Labarga, M. Martinez, J. del Peso, J. Puga, J. Terron, J.F. de Trocóniz, F. Corriveau, D.S. Hanna, J. Hartmann, L.W. Hung, J.N. Lim, C.G. Matthews, P.M. Patel, M. Riveline, D.G. Stairs, M. St-Laurent, R. Ullmann, G. Zacek, T. Tsurugai, V. Bashkirov, B.A. Dolgoshein, A. Stifutkin, G.L. Bashindzhagyan, P.F. Ermolov, L.K. Gladilin, Yu.A. Golubkov, V.D. Kobrin, I.A. Korzhavina, V.A. Kuzmin, O.Yu. Lukina, A.S. Proskuryakov, A.A. Savin, L.M. Shcheglova, A.N. Solomin, N.P. Zotov, M. Botje, F. Chlebana, J. Engelen, M. de Kamps, P. Kooijman, A. Kruse, A. van Sighem, H. Tiecke, W. Verkerke, J. Vossebeld, M. Vreeswijk, L. Wiggers, E. de Wolf, R. van Woudenberg, D. Acosta, B. Bylsma, L.S. Durkin, J. Gilmore, C. Li, T.Y. Ling, P. Nylander, I.H. Park, T.A. Romanowski, D.S. Bailey, R.J. Cashmore, A.M. Cooper-Sarkar, R.C.E. Devenish, N. Harnew, M. Lancaster, L. Lindemann, J.D. McFall, C. Nath, V.A. Noyes, A. Quadt, J.R. Tickner, H. Uijterwaal, R. Walczak, D.S. Waters, F.F. Wilson, T. Yip, G. Abbiendi, A. Bertolin, R. Brugnera, R. Carlin, F. Dal Corso, M. De Giorgi, U. Dosselli, S. Limentani, M. Morandin, M. Posocco, L. Stanco, R. Stroili, C. Voci, F. Zuin, J. Bulmahn, R.G. Feild, B.Y. Oh, J.J. Whitmore, G. D'Agostini, G. Marini, A. Nigro, E. Tassi, J.C. Hart, N.A. McCubbin, T.P. Shah, E. Barberis, T. Dubbs, C. Heusch, M. Van Hook, W. Lockman, J.T. Rahn, H.F.-W. Sadrozinski, A. Seiden, D.C. Williams, J. Biltzinger, R.J. Seifert, O. Schwarzer, A.H. Walenta, G. Zech, H. Abramowicz, G. Briskin, S. Dagan, A. Levy, J.I. Fleck, M. Inuzuka, T. Ishii, M. Kuze, S. Mine, M. Nakao, I. Suzuki, K. Tokushuku, K. Umemori, S. Yamada, Y. Yamazaki, M. Chiba, R. Hamatsu, T. Hirose, K. Homma, S. Kitamura, T. Matsushita, K. Yamauchi, R. Cirio, M. Costa, M.I. Ferrero, S. Maselli, C. Peroni, R. Sacchi, A. Solano, A. Staiano, M. Dardo, D.C. Bailey, F. Benard, M. Brkic, G.F. Hartner, K.K. Joo, G.M. Levman, J.F. Martin, R.S. Orr, S. Polenz, C.R. Sampson, D. Simmons, R.J. Teuscher, J.M. Butterworth, C.D. Catterall, T.W. Jones, P.B. Kaziewicz, J.B. Lane, R.L. Saunders, J. Shulman, M.R. Sutton, B. Lu, L.W. Mo, W. Bogusz, J. Ciborowski, J. Gajewski, G. Grzelak, M. Kasprzak, M. Krzyżanowski, K. Muchorowski, R.J. Nowak, J.M. Pawlak, T. Tymieniecka, A.K. Wróblewski, J.A. Zakrzewski, A.F. Żarnecki, M. Adamus, C. Coldewey, Y. Eisenberg, U. Karshon, D. Revel, D. Zer-Zion, W.F. Badgett, J. Breitweg, D. Chapin, R. Cross, S. Dasu, C. Foudas, R.J. Loveless, S. Mattingly, D.D. Reeder, S. Silverstein, W.H. Smith, A. Vaiciulis, M. Wodarczyk, S. Bhadra, M.L. Cardy, C.-P. Fagerstroem, W.R. Frisken, M. Khakzad, W.N. Murray, W.B. Schmidke, and ZEUS at HERA (IHEF, IoP, FNWI)
Subjects: Diffraction, Nuclear and High Energy Physics, Particle physics, Meson, 7. Clean energy, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, PHYSICS, Cross section (physics), DESIGN, 0103 physical sciences, 010306 general physics, DETECTOR, ZEUS, ZEUS BARREL CALORIMETER, CONSTRUCTION, Physics, Range (particle radiation), ZEUS (particle detector), 010308 nuclear & particles physics, HERA, Helicity, Exponential function, High Energy Physics::Experiment
Abstract: The production of $\phi$ mesons in the reaction $e^{+}p \rightarrow e^{+} \phi p$ ($\phi \rightarrow K^{+}K^{-}$) at a median $Q^{2}$ of $10^{-4} \ \rm{GeV^2}$ has been studied with the ZEUS detector at HERA. The differential $\phi$ photoproduction cross section $d\sigma/dt$ has an exponential shape and has been determined in the kinematic range $0.1, Comment: 23 pages, including 6 post script figures
Published: 1996

8. Rapidity gaps between jets in photoproduction at HERA

Author: M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. Repond, R. Stanek, R.L. Talaga, H. Zhang, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, P. Bruni, G. Cara Romeo, G. Castellini, M. Chiarini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi, A. Margotti, T. Massam, R. Nania, C. Nemoz, F. Palmonari, A. Polini, G. Sartorelli, R. Timellini, Y. Zamora Garcia, A. Zichichi, A. Bornheim, J. Crittenden, K. Desch, B. Diekmann, T. Doeker, M. Eckert, L. Feld, A. Frey, M. Geerts, M. Grothe, H. Hartmann, K. Heinloth, L. Heinz, E. Hilger, H.-P. Jakob, U.F. Katz, S. Mengel, J. Mollen, E. Paul, M. Pfeiffer, Ch. Rembser, D. Schramm, J. Stamm, R. Wedemeyer, S. Campbell-Robson, A. Cassidy, W.N. Cottingham, N. Dyce, B. Foster, S. George, M.E. Hayes, G.P. Heath, H.F. Heath, C.J.S. Morgado, J.A. O'Mara, D. Piccioni, D.G. Roff, R.J. Tapper, R. Yoshida, R.R. Rau, M. Arneodo, R. Ayad, M. Capua, A. Garfagnini, L. Iannotti, M. Schioppa, G. Susinno, A. Bernstein, A. Caldwell, N. Cartiglia, J.A. Parsons, S. Ritz, F. Sciulli, P.B. Straub, L. Wai, S. Yang, Q. Zhu, P. Borzemski, J. Chwastowski, A. Eskreys, K. Piotrzkowski, M. Zachara, L. Zawiejski, L. Adamczyk, B. Bednarek, K. Jeleń, D. Kisielewska, T. Kowalski, M. Przybycień, E. Rulikowska-Zarȩbska, L. Suszycki, J. Zaja̧c, A. Kotański, L.A.T. Bauerdick, U. Behrens, H. Beier, J.K. Bienlein, C. Coldewey, O. Deppe, K. Desler, G. Drews, M. Flasiński, D.J. Gilkinson, C. Glasman, P. Göttlicher, J. Groß-Knetter, B. Gutjahr, T. Haas, W. Hain, D. Hasell, H. Heßling, Y. Iga, K.F. Johnson, P. Joos, M. Kasemann, R. Klanner, W. Koch, L. Köpke, U. Kötz, H. Kowalski, J. Labs, A. Ladage, B. Löhr, M. Löwe, D. Lüke, J. Mainusch, O. Mańczak, T. Monteiro, J.S.T. Ng, S. Nickel, D. Notz, K. Ohrenberg, M. Roco, M. Rohde, J. Roldán, U. Schneekloth, W. Schulz, F. Selonke, E. Stiliaris, B. Surrow, T. Voß, D. Westphal, G. Wolf, C. Youngman, W. Zeuner, J.F. Zhou, H.J. Grabosch, A. Kharchilava, A. Leich, S.M. Mari, M.C.K. Mattingly, A. Meyer, S. Schlenstedt, N. Wulff, G. Barbagli, E. Gallo, P. Pelfer, G. Anzivino, G. Maccarrone, S. De Pasquale, L. Votano, A. Bamberger, S. Eisenhardt, A. Freidhof, S. Söldner-Rembold, J. Schroeder, T. Trefzger, N.H. Brook, P.J. Bussey, A.T. Doyle, D.H. Saxon, M.L. Utley, A.S. Wilson, A. Dannemann, U. Holm, D. Horstmann, T. Neumann, R. Sinkus, K. Wick, E. Badura, B.D. Burow, L. Hagge, E. Lohrmann, J. Milewski, M. Nakahata, N. Pavel, G. Poelz, W. Schott, F. Zetsche, T.C. Bacon, N. Bruemmer, I. Butterworth, V.L. Harris, B.Y.H. Hung, K.R. Long, D.B. Miller, P.P.O. Morawitz, A. Prinias, J.K. Sedgbeer, A.F. Whitfield, U. Mallik, E. McCliment, M.Z. Wang, S.M. Wang, J.T. Wu, P. Cloth, D. Filges, S.H. An, S.M. Hong, S.V. Nam, S.K. Park, M.H. Suh, S.H. Yon, R. Imlay, S. Kartik, H.-J. Kim, R.R. McNeil, W. Metcalf, V.K. Nadendla, F. Barreiro, G. Cases, J.P. Fernandez, R. Graciani, J.M. Hernández, L. Hervás, L. Labarga, M. Martinez, J. del Peso, J. Puga, J. Terron, J.F. de Trocóniz, G.R. Smith, F. Corriveau, D.S. Hanna, J. Hartmann, L.W. Hung, J.N. Lim, C.G. Matthews, P.M. Patel, L.E. Sinclair, D.G. Stairs, M. St.Laurent, R. Ullmann, G. Zacek, V. Bashkirov, B.A. Dolgoshein, A. Stifutkin, G.L. Bashindzhagyan, P.F. Ermolov, L.K. Gladilin, Yu.A. Golubkov, V.D. Kobrin, I.A. Korzhavina, V.A. Kuzmin, O.Yu. Lukina, A.S. Proskuryakov, A.A. Savin, L.M. Shcheglova, A.N. Solomin, N.P. Zotov, M. Botje, F. Chlebana, A. Dake, J. Engelen, M. de Kamps, P. Kooijman, A. Kruse, H. Tiecke, W. Verkerke, M. Vreeswijk, L. Wiggers, E. de Wolf, R. van Woudenberg, D. Acosta, B. Bylsma, L.S. Durkin, J. Gilmore, K. Honscheid, C. Li, T.Y. Ling, K.W. McLean, P. Nylander, I.H. Park, T.A. Romanowski, R. Seidlein, D.S. Bailey, A. Byrne, R.J. Cashmore, A.M. Cooper-Sarkar, R.C.E. Devenish, N. Harnew, M. Lancaster, L. Lindemann, J.D. McFall, C. Nath, V.A. Noyes, A. Quadt, J.R. Tickner, H. Uijterwaal, R. Walczak, D.S. Waters, F.F. Wilson, T. Yip, G. Abbiendi, A. Bertolin, R. Brugnera, R. Carlin, F. Dal Corso, M. De Giorgi, U. Dosselli, S. Limentani, M. Morandin, M. Posocco, L. Stanco, R. Stroili, C. Voci, J. Bulmahn, J.M. Butterworth, R.G. Feild, B.Y. Oh, J.R. Okrasinski, J.J. Whitmore, G. D'Agostini, G. Marini, A. Nigro, E. Tassi, J.C. Hart, N.A. McCubbin, K. Prytz, T.P. Shah, T.L. Short, E. Barberis, T. Dubbs, C. Heusch, M. Van Hook, W. Lockman, J.T. Rahn, H.F.-W. Sadrozinski, A. Seiden, D.C. Williams, J. Biltzinger, R.J. Seifert, O. Schwarzer, A.H. Walenta, G. Zech, H. Abramowicz, G. Briskin, S. Dagan, C. Händel-Pikielny, A. Levy, J.I. Fleck, T. Hasegawa, M. Hazumi, T. Ishii, M. Kuze, S. Mine, Y. Nagasawa, M. Nakao, I. Suzuki, K. Tokushuku, S. Yamada, Y. Yamazaki, M. Chiba, R. Hamatsu, T. Hirose, K. Homma, S. Kitamura, Y. Nakamitsu, K. Yamauchi, R. Cirio, M. Costa, M.I. Ferrero, L. Lamberti, S. Maselli, C. Peroni, R. Sacchi, A. Solano, A. Staiano, M. Dardo, D.C. Bailey, D. Bandyopadhyay, F. Benard, M. Brkic, D.M. Gingrich, G.F. Hartner, K.K. Joo, G.M. Levman, J.F. Martin, R.S. Orr, S. Polenz, C.R. Sampson, R.J. Teuscher, C.D. Catterall, T.W. Jones, P.B. Kaziewicz, J.B. Lane, R.L. Saunders, J. Shulman, K. Blankenship, B. Lu, L.W. Mo, W. Bogusz, K. Charchuła, J. Ciborowski, J. Gajewski, G. Grzelak, M. Kasprzak, M. Krzyżanowski, K. Muchorowski, R.J. Nowak, J.M. Pawlak, T. Tymieniecka, A.K. Wróblewski, J.A. Zakrzewski, A.F. Żarnecki, M. Adamus, Y. Eisenberg, U. Karshon, D. Revel, D. Zer-Zion, I. Ali, W.F. Badgett, B. Behrens, S. Dasu, C. Fordham, C. Foudas, A. Goussiou, R.J. Loveless, D.D. Reeder, S. Silverstein, W.H. Smith, A. Vaiciulis, M. Wodarczyk, T. Tsurugai, S. Bhadra, M.L. Cardy, C.-P. Fagerstroem, W.R. Frisken, K.M. Furutani, M. Khakzad, W.N. Murray, W.B. Schmidke, and ZEUS at HERA (IHEF, IoP, FNWI)
Subjects: Nuclear and High Energy Physics, Particle physics, COLLISIONS, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, EVENTS, High Energy Physics - Experiment (hep-ex), MONTE-CARLO, DESIGN, 0103 physical sciences, Rapidity, 010306 general physics, Nuclear Experiment, Physics, Research Groups and Centres\Physics\Low Temperature Physics, ZEUS (particle detector), CONSTRUCTION, 010308 nuclear & particles physics, Faculty of Science\Physics, ZEUS, PARTON ELASTIC-SCATTERING, ZEUS BARREL CALORIMETER, HERA, diffractive scattering, photoproduction, High Energy Physics::Experiment
Abstract: Photoproduction events which have two or more jets have been studied in the $W_{\gamma p}$ range 135~GeV $< W_{\gamma p}, Comment: 19 pages, latex, 3 figures appended as uuencoded file. Author list corrected
Published: 1996

9. Measurement of Alpha(s) From Jet Rates In Deep-inelastic Scattering At Hera

Author: M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. Repond, R. Stanek, R.L. Talaga, H. Zhang, R. Ayad, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, P. Bruni, G. Cara Romeo, G. Castellini, M. Chiarini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi, A. Margotti, T. Massam, R. Nania, C. Nemoz, F. Palmonari, A. Polini, G. Sartorelli, R. Timellini, Y. Zamora Garcia, A. Zichichi, A. Bargende, A. Bornheim, J. Crittenden, K. Desch, B. Diekmann, T. Doeker, M. Eckert, L. Feld, A. Frey, M. Geerts, M. Grothe, H. Hartmann, K. Heinloth, E. Hilger, H.-P. Jakob, U.F. Katz, S. Mengel, J. Mollen, E. Paul, M. Pfeiffer, Ch. Rembser, D. Schramm, J. Stamm, R. Wedemeyer, S. Campbell-Robson, A. Cassidy, W.N. Cottingham, N. Dyce, B. Foster, S. George, M.E. Hayes, G.P. Heath, H.F. Heath, C.J.S. Morgado, J.A. O'Mara, D. Piccioni, D.G. Roff, R.J. Tapper, R. Yoshida, R.R. Rau, M. Arneodo, M. Capua, A. Garfagnini, L. Iannotti, M. Schioppa, G. Susinno, A. Bernstein, A. Caldwell, N. Cartiglia, J.A. Parsons, S. Ritz, F. Sciulli, P.B. Straub, L. Wai, S. Yang, Q. Zhu, P. Borzemski, J. Chwastowski, A. Eskreys, K. Piotrzkowski, M. Zachara, L. Zawiejski, L. Adamczyk, B. Bednarek, K. Jeleń, D. Kisielewska, T. Kowalski, E. Rulikowska-Zarȩbska, L. Suszycki, J. Zaja̧c, A. Kotański, M. Przybycień, L.A.T. Bauerdick, U. Behrens, H. Beier, J.K. Bienlein, C. Coldewey, O. Deppe, K. Desler, G. Drews, M. Flasiński, D.J. Gilkinson, C. Glasman, P. Göttlicher, J. Große-Knetter, B. Gutjahr, T. Haas, W. Hain, D. Hasell, H. Heßling, Y. Iga, K.F. Johnson, P. Joos, M. Kasemann, R. Klanner, W. Koch, L. Köpke, U. Kötz, H. Kowalski, J. Labs, A. Ladage, B. Löhr, M. Löwe, D. Lüke, J. Mainusch, O. Mańczak, T. Monteiro, J.S.T. Ng, S. Nickel, D. Notz, K. Ohrenberg, M. Roco, M. Rohde, J. Roldán, U. Schneekloth, W. Schulz, F. Selonke, E. Stiliaris, B. Surrow, T. Voß, D. Westphal, G. Wolf, C. Youngman, W. Zeuner, J.F. Zhou, H.J. Grabosch, A. Kharchilava, A. Leich, M.C.K. Mattingly, S.M. Mari, A. Meyer, S. Schlenstedt, N. Wulff, G. Barbagli, P. Pelfer, G. Anzivino, G. Maccarrone, S. De Pasquale, L. Votano, A. Bamberger, S. Eisenhardt, A. Freidhof, S. Söldner-Rembold, J. Schroeder, T. Trefzger, N.H. Brook, P.J. Bussey, A.T. Doyle, D.H. Saxon, M.L. Utley, A.S. Wilson, A. Dannemann, U. Holm, D. Horstmann, T. Neumann, R. Sinkus, K. Wick, E. Badura, B.D. Burow, L. Hagge, E. Lohrmann, J. Milewski, M. Nakahata, N. Pavel, G. Poelz, W. Schott, F. Zetsche, T.C. Bacon, N. Bruemmer, I. Butterworth, E. Gallo, V.L. Harris, B.Y.H. Hung, K.R. Long, D.B. Miller, P.P.O. Morawitz, A. Prinias, J.K. Sedgbeer, A.F. Whitfield, U. Mallik, E. McCliment, M.Z. Wang, S.M. Wang, J.T. Wu, P. Cloth, D. Filges, S.H. An, S.M. Hong, S.W. Nam, S.K. Park, M.H. Suh, S.H. Yon, R. Imlay, S. Kartik, H.-J. Kim, R.R. McNeil, W. Metcalf, V.K. Nadendla, F. Barreiro, G. Cases, J.P. Fernandez, R. Graciani, J.M. Hernández, L. Hervás, L. Labarga, M. Martinez, J. del Peso, J. Puga, J. Terron, J.F. de Trocóniz, G.R. Smith, F. Corriveau, D.S. Hanna, J. Hartmann, L.W. Hung, J.N. Lim, C.G. Matthews, P.M. Patel, L.E. Sinclair, D.G. Stairs, M. St.Laurent, R. Ullmann, G. Zacek, V. Bashkirov, B.A. Dolgoshein, A. Stifutkin, G.L. Bashindzhagyan, P.F. Ermolov, L.K. Gladilin, Yu.A. Golubkov, V.D. Kobrin, I.A. Korzhavina, V.A. Kuzmin, O.Yu. Lukina, A.S. Proskuryakov, A.A. Savin, L.M. Shcheglova, A.N. Solomin, N.P. Zotov, M. Botje, F. Chlebana, A. Dake, J. Engelen, M. de Kamps, P. Kooijman, A. Kruse, H. Tiecke, W. Verkerke, M. Vreeswijk, L. Wiggers, E. de Wolf, R. van Woudenberg, D. Acosta, B. Bylsma, L.S. Durkin, J. Gilmore, K. Honscheid, C. Li, T.Y. Ling, K.W. McLean, W.N. Murray, P. Nylander, I.H. Park, T.A. Romanowski, R. Seidlein, D.S. Bailey, A. Byrne, R.J. Cashmore, A.M. Cooper-Sarkar, R.C.E. Devenish, N. Harnew, M. Lancaster, L. Lindemann, J.D. McFall, C. Nath, V.A. Noyes, A. Quadt, J.R. Tickner, H. Uijterwaal, R. Walczak, D.S. Waters, F.F. Wilson, T. Yip, G. Abbiendi, A. Bertolin, R. Brugnera, R. Carlin, F. Dal Corso, M. De Giorgi, U. Dosselli, S. Limentani, M. Morandin, M. Posocco, L. Stanco, R. Stroili, C. Voci, J. Bulmahn, J.M. Butterworth, R.G. Feild, B.Y. Oh, J.R. Okrasinski, J.J. Whitmore, G. D'Agostini, G. Marini, A. Nigro, E. Tassi, J.C. Hart, N.A. McCubbin, K. Prytz, T.P. Shah, T.L. Short, E. Barberis, T. Dubbs, C. Heusch, M. Van Hook, W. Lockman, J.T. Rahn, H.F.-W. Sadrozinski, A. Seiden, D.C. Williams, J. Biltzinger, R.J. Seifert, O. Schwarzer, A.H. Walenta, G. Zech, H. Abramowicz, G. Briskin, S. Dagan, C. Händel-Pikielny, A. Levy, J.I. Fleck, T. Hasegawa, M. Hazumi, T. Ishii, M. Kuze, S. Mine, Y. Nagasawa, M. Nakao, I. Suzuki, K. Tokushuku, S. Yamada, Y. Yamazaki, M. Chiba, R. Hamatsu, T. Hirose, K. Homma, S. Kitamura, Y. Nakamitsu, K. Yamauchi, R. Cirio, M. Costa, M.I. Ferrero, L. Lamberti, S. Maselli, C. Peroni, R. Sacchi, A. Solano, A. Staiano, M. Dardo, D.C. Bailey, D. Bandyopadhyay, F. Benard, M. Brkic, D.M. Gingrich, G.F. Hartner, K.K. Joo, G.M. Levman, J.F. Martin, R.S. Orr, S. Polenz, C.R. Sampson, R.J. Teuscher, C.D. Catterall, T.W. Jones, P.B. Kaziewicz, J.B. Lane, R.L. Saunders, J. Shulman, K. Blankenship, B. Lu, L.W. Mo, W. Bogusz, K. Charchuła, J. Ciborowski, J. Gajewski, G. Grzelak, M. Kasprzak, M. Krzyżanowski, K. Muchorowski, R.J. Nowak, J.M. Pawlak, T. Tymieniecka, A.K. Wróblewski, J.A. Zakrzewski, A.F. Żarnecki, M. Adamus, Y. Eisenberg, U. Karshon, D. Revel, D. Zer-Zion, I. Ali, W.F. Badgett, B. Behrens, S. Dasu, C. Fordham, C. Foudas, A. Goussiou, R.J. Loveless, D.D. Reeder, S. Silverstein, W.H. Smith, A. Vaiciulis, M. Wodarczyk, T. Tsurugai, S. Bhadra, M.L. Cardy, C.-P. Fagerstroem, W.R. Frisken, K.M. Furutani, M. Khakzad, and W.B. Schmidke
Subjects: Nuclear and High Energy Physics, Particle physics, jet production, ENERGIES, Astrophysics::High Energy Astrophysical Phenomena, Parton, PROTON SCATTERING, 01 natural sciences, perturbative QCD, High Energy Physics - Experiment, CROSS-SECTIONS, Nuclear physics, EVENT GENERATOR, MONTE-CARLO, QCD JETS, ZEUS, CALORIMETER, FRAGMENTATION, DEPENDENCE, 0103 physical sciences, determination of alpha_s, 010306 general physics, Quantum chromodynamics, Physics, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Perturbative QCD, HERA, Deep inelastic scattering, High Energy Physics::Experiment
Abstract: Jet production in deep inelastic scattering for $120, Comment: 22 pages, latex, 4 figures appended as uuencoded file
Published: 1995

10. Measurement of the Cross-section For the Reaction Gamma-p-]j/psi-p With the Zeus Detector At Hera

Author: M Derrick, D Krakauer, S Magill, D Mikunas, B Musgrave, J Repond, R Stanek, R.L Talaga, H Zhang, R Ayad, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, P Bruni, G Cara Romeo, G Castellini, M Chiarini, L Cifarelli, F Cindolo, A Contin, M Corradi, I Gialas, P Giusti, G Iacobucci, G Laurenti, G Levi, A Margotti, T Massam, R Nania, C Nemoz, F Palmonari, A Polini, G Sartorelli, R Timellini, Y Zamora Garcia, A Zichichi, A Bargende, J Crittenden, K Desch, B Diekmann, T Doeker, M Eckert, L Feld, A Frey, M Geerts, G Geitz, M Grothe, T Haas, H Hartmann, D Haun, K Heinloth, E Hilger, H.-P Jakob, U.F Katz, S.M Mari, A Mass, S Mengel, J Mollen, E Paul, Ch Rembser, R Schattevoy, D Schramm, J Stamm, R Wedemeyer, S Campbell-Robson, A Cassidy, N Dyce, B Foster, S George, R Gilmore, G.P Heath, H.F Heath, T.J Llewellyn, C.J.S Morgado, D.J.P Norman, J.A O'Mara, R.J Tapper, S.S Wilson, R Yoshida, R.R Rau, M Arneodo, L Iannotti, M Schioppa, G Susinno, A Bernstein, A Caldwell, N Cartiglia, J.A Parsons, S Ritz, F Sciulli, P.B Straub, L Wai, S Yang, Q Zhu, P Borzemski, J Chwastowski, A Eskreys, K Piotrzkowski, M Zachara, L Zawiejski, L Adamczyk, B Bednarek, K Jeleń, D Kisielewska, T Kowalski, E Rulikowska-Zarȩbska, L Suszycki, J Zaja̧c, A Kotański, M Przybycień, L.A.T Bauerdick, U Behrens, H Beier, J.K Bienlein, C Coldewey, O Deppe, K Desler, G Drews, M Flasiński, D.J Gilkinson, C Glasman, P Göttlicher, J Große-Knetter, B Gutjahr, W Hain, D Hasell, H Heßling, Y Iga, P Joos, M Kasemann, R Klanner, W Koch, L Köpke, U Kötz, H Kowalski, J Labs, A Ladage, B Löhr, M Löwe, D Lüke, O Mańczak, T Monteiro, J.S.T Ng, S Nickel, D Notz, K Ohrenberg, M Roco, M Rohde, J Roldán, U Schneekloth, W Schulz, F Selonke, E Stiliaris, B Surrow, T Voß, D Westphal, G Wolf, C Youngman, J.F Zhou, H.J Grabosch, A Kharchilava, A Leich, M.C.K Mattingly, A Meyer, S Schlenstedt, N Wulff, G Barbagli, P Pelfer, G Anzivino, G Maccarrone, S De Pasquale, L Votano, A Bamberger, S Eisenhardt, A Freidhof, S Söldner-Rembold, J Schroeder, T Trefzger, N.H Brook, P.J Bussey, A.T Doyle, J.I Fleck, D.H Saxon, M.L Utley, A.S Wilson, A Dannemann, U Holm, D Horstmann, T Neumann, R Sinkus, K Wick, E Badura, B.D Burow, L Hagge, E Lohrmann, J Mainusch, J Milewski, M Nakahata, N Pavel, G Poelz, W Schott, F Zetsche, T.C Bacon, I Butterworth, E Gallo, V.L Harris, B.Y.H Hung, K.R Long, D.B Miller, P.P.O Morawitz, A Prinias, J.K Sedgbeer, A.F Whitfield, U Mallik, E McCliment, M.Z Wang, S.M Wang, J.T Wu, Y Zhang, P Cloth, D Filges, S.H An, S.M Hong, S.W Nam, S.K Park, M.H Suh, S.H Yon, R Imlay, S Kartik, H.-J Kim, R.R McNeil, W Metcalf, V.K Nadendla, F Barreiro, G Cases, R Graciani, J.M Hernández, L Hervás, L Labarga, J del Peso, J Puga, J Terron, J.F de Trocóniz, G.R Smith, F Corriveau, D.S Hanna, J Hartmann, L.W Hung, J.N Lim, C.G Matthews, P.M Patel, L.E Sinclair, D.G Stairs, M St.Laurent, R Ullmann, G Zacek, V Bashkirov, B.A Dolgoshein, A Stifutkin, G.L Bashindzhagyan, P.F Ermolov, L.K Gladilin, Y.A Golubkov, V.D Kobrin, V.A Kuzmin, A.S Proskuryakov, A.A Savin, L.M Shcheglova, A.N Solomin, N.P Zotov, M Botje, F Chlebana, A Dake, J Engelen, M de Kamps, P Kooijman, A Kruse, H Tiecke, W Verkerke, M Vreeswijk, L Wiggers, E de Wolf, R van Woudenberg, D Acosta, B Bylsma, L.S Durkin, K Honscheid, C Li, T.Y Ling, K.W McLean, W.N Murray, I.H Park, T.A Romanowski, R Seidlein, D.S Bailey, G.A Blair, A Byrne, R.J Cashmore, A.M Cooper-Sarkar, D Daniels, R.C.E Devenish, N Harnew, M Lancaster, P.E Luffman, L Lindemann, J.D McFall, C Nath, V.A Noyes, A Quadt, H Uijterwaal, R Walczak, F.F Wilson, T Yip, G Abbiendi, A Bertolin, R Brugnera, R Carlin, F Dal Corso, M De Giorgi, U Dosselli, S Limentani, M Morandin, M Posocco, L Stanco, R Stroili, C Voci, J Bulmahn, J.M Butterworth, R.G Feild, B.Y Oh, J.J Whitmore, G D'Agostini, G Marini, A Nigro, E Tassi, J.C Hart, N.A McCubbin, K Prytz, T.P Shah, T.L Short, E Barberis, T Dubbs, C Heusch, M Van Hook, B Hubbard, W Lockman, J.T Rahn, H.F.-W Sadrozinski, A Seiden, J Biltzinger, R.J Seifert, A.H Walenta, G Zech, H Abramowicz, G Briskin, S Dagan, A Levy, T Hasegawa, M Hazumi, T Ishii, M Kuze, S Mine, Y Nagasawa, M Nakao, I Suzuki, K Tokushuku, S Yamada, Y Yamazaki, M Chiba, R Hamatsu, T Hirose, K Homma, S Kitamura, Y Nakamitsu, K Yamauchi, R Cirio, M Costa, M.I Ferrero, L Lamberti, S Maselli, C Peroni, R Sacchi, A Solano, A Staiano, M Dardo, D.C Bailey, D Bandyopadhyay, F Benard, M Brkic, M.B Crombie, D.M Gingrich, G.F Hartner, K.K Joo, G.M Levman, J.F Martin, R.S Orr, C.R Sampson, R.J Teuscher, C.D Catterall, T.W Jones, P.B Kaziewicz, J.B Lane, R.L Saunders, J Shulman, K Blankenship, B Lu, L.W Mo, W Bogusz, K Charchuła, J Ciborowski, J Gajewski, G Grzelak, M Kasprzak, M Krzyżanowski, K Muchorowski, R.J Nowak, J.M Pawlak, T Tymieniecka, A.K Wróblewski, J.A Zakrzewski, A.F Żarnecki, M Adamus, Y Eisenberg, U Karshon, D Revel, D Zer-Zion, I Ali, W.F Badgett, B Behrens, S Dasu, C Fordham, C Foudas, A Goussiou, R.J Loveless, D.D Reeder, S Silverstein, W.H Smith, A Vaiciulis, M Wodarczyk, T Tsurugai, S Bhadra, M.L Cardy, C.-P Fagerstroem, W.R Frisken, K.M Furutani, M Khakzad, and W.B Schmidke
Subjects: Nuclear and High Energy Physics, Particle physics, Proton, LUND MONTE-CARLO, ZEUS, ELASTIC-SCATTERING, BARREL CALORIMETER, PHOTOPRODUCTION, J/PSI, DESIGN, 01 natural sciences, 7. Clean energy, High Energy Physics - Experiment, Nuclear physics, Cross section (physics), 0103 physical sciences, photoproduction, J/ψ cross section measurement, 010306 general physics, Nuclear Experiment, Quantum chromodynamics, Physics, Elastic scattering, ZEUS (particle detector), Luminosity (scattering theory), 010308 nuclear & particles physics, HERA, Gluon, High Energy Physics::Experiment
Abstract: This paper reports the cross section measurements for the process ep $\rightarrow$ e~\jpsi~p for $Q^2 < 4$ GeV$^2$ at $\sqrt s = 296$ GeV, based on an integrated luminosity of about 0.5~pb$^{-1}$, using the ZEUS detector. The \jpsi~was detected in its $\rm e^{+}e^{-}$ and $\rm \mu^{+}\mu^{-}$ decay modes. The photoproduction cross section was measured to be $52^{ \ +7}_{-12}\pm 10$~nb at an average $\gamma$p centre of mass energy of 67 GeV and $71^{+13}_{-20}\pm 12$~nb at 114 GeV. The significant rise of the cross section compared to lower energy measurements is not in agreement with VDM models, but can be described by QCD inspired models if a rise in the gluon momentum density at low $x$ in the proton is assumed., Comment: 21 pages, latex, 4 figures appended as uuencoded file
Published: 1995

11. Measurement of the reaction γ*p→φp in deep inelastic e+p scattering at HERA

Author: M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J.R. Okrasinski, J. Repond, R. Stanek, R.L. Talaga, H. Zhang, M.C.K. Mattingly, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, P. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi, A. Margotti, T. Massam, R. Nania, F. Palmonari, A. Polini, G. Sartorelli, Y.Zamora Garcia, A. Zichichi, C. Amelung, A. Bornheim, J. Crittenden, R. Deffner, T. Doeker, M. Eckert, L. Feld, A. Frey, M. Geerts, M. Grothe, H. Hartmann, K. Heinloth, L. Heinz, E. Hilger, H.-P. Jakob, U.F. Katz, S. Mengel, E. Paul, M. Pfeiffer, Ch. Rembser, D. Schramm, J. Stamm, R. Wedemeyer, S. Campbell-Robson, A. Cassidy, W.N. Cottingham, N. Dyce, B. Foster, S. George, M.E. Hayes, G.P. Heath, H.F. Heath, D. Piccioni, D.G. Roff, R.J. Tapper, R. Yoshida, M. Arneodo, R. Ayad, M. Capua, A. Garfagnini, L. Iannotti, M. Schioppa, G. Susinno, A. Caldwell, N. Cartiglia, Z. Jing, W. Liu, J.A. Parsons, S. Ritz, F. Sciulli, P.B. Straub, L. Wai, S. Yang, Q. Zhu, P. Borzemski, J. Chwastowski, A. Eskreys, Z. Jakubowski, M.B. Przybycień, M. Zachara, L. Zawiejski, L. Adamczyk, B. Bednarek, K. Jeleń, D. Kisielewska, T. Kowalski, M. Przybycień, E. Rulikowska-Zarȩbska, L. Suszycki, J. Zaja̧c, Z. Duliński, A. Kotański, G. Abbiendi, L.A.T. Bauerdick, U. Behrens, H. Beier, J.K. Bienlein, G. Cases, O. Deppe, K. Desler, G. Drews, M. Flasiński, D.J. Gilkinson, C. Glasman, P. Göttlicher, J. Große-Knetter, T. Haas, W. Hain, D. Hasell, H. Heßling, Y. Iga, K.F. Johnson, P. Joos, M. Kasemann, R. Klanner, W. Koch, U. Kötz, H. Kowalski, J. Labs, A. Ladage, B. Löhr, M. Löwe, D. Lüke, J. Mainusch, O. Mańczak, J. Milewski, T. Monteiro, J.S.T. Ng, D. Notz, K. Ohrenberg, K. Piotrzkowski, M. Roco, M. Rohde, J. Roldán, U. Schneekloth, W. Schulz, F. Selonke, B. Surrow, T. Voß, D. Westphal, G. Wolf, U. Wollmer, C. Youngman, W. Zeuner, H.J. Grabosch, A. Kharchilava, S.M. Mari, A. Meyer, S. Schlenstedt, N. Wulff, G. Barbagli, E. Gallo, P. Pelfer, G. Maccarrone, S. De Pasquale, L. Votano, A. Bamberger, S. Eisenhardt, T. Trefzger, S. Wölfle, J.T. Bromley, N.H. Brook, P.J. Bussey, A.T. Doyle, D.H. Saxon, L.E. Sinclair, M.L. Utley, A.S. Wilson, A. Dannemann, U. Holm, D. Horstmann, R. Sinkus, K. Wick, B.D. Burow, L. Hagge, E. Lohrmann, N. Pavel, G. Poelz, W. Schott, F. Zetsche, T.C. Bacon, N. Brümmer, I. Butterworth, V.L. Harris, G. Howell, B.H.Y. Hung, L. Lamberti, K.R. Long, D.B. Miller, A. Prinias, J.K. Sedgbeer, D. Sideris, A.F. Whitfield, U. Mallik, M.Z. Wang, S.M. Wang, J.T. Wu, P. Cloth, D. Filges, S.H. An, G.H. Cho, B.J. Ko, S.B. Lee, S.W. Nam, H.S. Park, S.K. Park, S. Kartik, H.-J. Kim, R.R. McNeil, W. Metcalf, V.K. Nadendla, F. Barreiro, J.P. Fernandez, R. Graciani, J.M. Hernández, L. Hervás, L. Labarga, M. Martinez, J. del Peso, J. Puga, J. Terron, J.F. de Trocóniz, F. Corriveau, D.S. Hanna, J. Hartmann, L.W. Hung, J.N. Lim, C.G. Matthews, P.M. Patel, M. Riveline, D.G. Stairs, M. St-Laurent, R. Ullmann, G. Zacek, T. Tsurugai, V. Bashkirov, B.A. Dolgoshein, A. Stifutkin, G.L. Bashindzhagyan, P.F. Ermolov, L.K. Gladilin, Yu.A. Golubkov, V.D. Kobrin, I.A. Korzhavina, V.A. Kuzmin, O.Yu. Lukina, A.S. Proskuryakov, A.A. Savin, L.M. Shcheglova, A.N. Solomin, N.P. Zotov, M. Botje, F. Chlebana, J. Engelen, M. de Kamps, P. Kooijman, A. Kruse, A. van Sighem, H. Tiecke, W. Verkerke, J. Vossebeld, M. Vreeswijk, L. Wiggers, E. de Wolf, R. van Woudenberg, D. Acosta, B. Bylsma, L.S. Durkin, J. Gilmore, C. Li, T.Y. Ling, P. Nylander, I.H. Park, T.A. Romanowski, D.S. Bailey, R.J. Cashmore, A.M. Cooper-Sarkar, R.C.E. Devenish, N. Harnew, M. Lancaster, L. Lindemann, J.D. McFall, C. Nath, V.A. Noyes, A. Quadt, J.R. Tickner, H. Uijterwaal, R. Walczak, D.S. Waters, F.F. Wilson, T. Yip, A. Bertolin, R. Brugnera, R. Carlin, F. Dal Corso, M. De Giorgi, U. Dosselli, S. Limentani, M. Morandin, M. Posocco, L. Stanco, R. Stroili, C. Voci, F. Zuin, J. Bulmahn, R.G. Feild, B.Y. Oh, J.J. Whitmore, G. D'Agostini, G. Marini, A. Nigro, E. Tassi, J.C. Hart, N.A. McCubbin, T.P. Shah, E. Barberis, T. Dubbs, C. Heusch, M. Van Hook, W. Lockman, J.T. Rahn, H.F.-W. Sadrozinski, A. Seiden, D.C. Williams, J. Biltzinger, R.J. Seifert, O. Schwarzer, A.H. Walenta, G. Zech, H. Abramowicz, G. Briskin, S. Dagan, A. Levy, J.I. Fleck, M. Inuzuka, T. Ishii, M. Kuze, S. Mine, M. Nakao, I. Suzuki, K. Tokushuku, K. Umemori, S. Yamada, Y. Yamazaki, M. Chiba, R. Hamatsu, T. Hirose, K. Homma, S. Kitamura, T. Matsushita, K. Yamauchi, R. Cirio, M. Costa, M.I. Ferrero, S. Maselli, C. Peroni, R. Sacchi, A. Solano, A. Staiano, M. Dardo, D.C. Bailey, F. Benard, M. Brkic, C.-P. Fagerstroem, G.F. Hartner, K.K. Joo, G.M. Levman, J.F. Martin, R.S. Orr, S. Polenz, C.R. Sampson, D. Simmons, R.J. Teuscher, J.M. Butterworth, C.D. Catterall, T.W. Jones, P.B. Kaziewicz, J.B. Lane, R.L. Saunders, J. Shulman, M.R. Sutton, B. Lu, L.W. Mo, W. Bogusz, J. Ciborowski, J. Gajewski, G. Grzelak, M. Kasprzak, M. Krzyżanowski, K. Muchorowski, R.J. Nowak, J.M. Pawlak, T. Tymieniecka, A.K. Wróblewski, J.A. Zakrzewski, A.F. Żarnecki, M. Adamus, C. Coldewey, Y. Eisenberg, D. Hochman, U. Karshon, D. Revel, D. Zer-Zion, W.F. Badgett, J. Breitweg, D. Chapin, R. Cross, S. Dasu, C. Foudas, R.J. Loveless, S. Mattingly, D.D. Reeder, S. Silverstein, W.H. Smith, A. Vaiciulis, M. Wodarczyk, S. Bhadra, M.L. Cardy, W.R. Frisken, M. Khakzad, W.N. Murray, and W.B. Schmidke
Subjects: Quark, Physics, Nuclear and High Energy Physics, Particle physics, Meson, Proton, 010308 nuclear & particles physics, Perturbative QCD, HERA, 7. Clean energy, 01 natural sciences, Zeus (malware), Gluon, Nuclear physics, Pomeron, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics
Abstract: The production of φ mesons in the reaction e+p → e+φp (φ → K+K−), for 7 Q 2 GeV 2 and virtual photon-proton centre of mass energies (W) in the range 42–134 GeV, has been studied with the ZEUS detector at HERA. When compared to lower energy data at similar Q 2, the results show that the γ ∗ p → φp cross section rises strongly with W. This behaviour is similar to that previously found for the γ ∗ p → ϱ 0 p cross section. This strong dependence cannot be explained by production through soft pomeron exchange. It is, however, consistent with perturbative QCD expectations, where it reflects the rise of the gluon momentum density in the proton at small x. The ratio of σ(φ) σ(ϱ 0 ) , which has previously been determined by ZEUS to be 0.065 ± 0.013 (stat.) in photoproduction at a mean W of 70 GeV, is measured to be 0.18 ± 0.05 (stat.) ± 0.03 (syst.) at a mean Q 2 of 12.3 GeV2 and mean W of ≈ 100 GeV and is thus approaching at large Q 2 the value of 2 9 predicted from the quark charges of the vector mesons and a flavour independent production mechanism.

12. Dijet angular distributions in direct and resolved photoproduction at HERA

Author: M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J.R. Okrasinski, J. Repond, R. Stanek, R.L. Talaga, H. Zhang, M.C.K. Mattingly, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, P. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi, A. Margotti, T. Massam, R. Nania, F. Palmonari, A. Polini, G. Sartorelli, Y. Zamora Garcia, A. Zichichi, C. Amelung, A. Bornheim, J. Crittenden, R. Deffner, T. Doeker, M. Eckert, L. Feld, A. Frey, M. Geerts, M. Grothe, H. Hartmann, K. Heinloth, L. Heinz, E. Hilger, H.-P. Jakob, U.F. Katz, S. Mengel, E. Paul, M. Pfeiffer, Ch. Rembser, D. Schramm, J. Stamm, R. Wedemeyer, S. Campbell-Robson, A. Cassidy, W.N. Cottingham, N. Dyce, B. Foster, S. George, M.E. Hayes, G.P. Heath, H.F. Heath, D. Piccioni, D.G. Roff, R.J. Tapper, R. Yoshida, M. Arneodo, R. Ayad, M. Capua, A. Garfagnini, L. Iannotti, M. Schioppa, G. Susinno, A. Caldwell, N. Cartiglia, Z. Jing, W. Liu, J.A. Parsons, S. Ritz, F. Sciulli, P.B. Straub, L. Wai, S. Yang, Q. Zhu, P. Borzemski, J. Chwastowski, A. Eskreys, Z. Jakubowski, M.B. Przybycień, M. Zachara, L. Zawiejski, L. Adamczyk, B. Bednarek, K. Jeleń, D. Kisielewska, T. Kowalski, M. Przybycień, E. Rulikowska-Zarȩbska, L. Suszycki, J. Zaja̧c, Z. Duliński, A. Kotański, G. Abbiendi, L.A.T. Bauerdick, U. Behrens, H. Beier, J.K. Bienlein, G. Cases, O. Deppe, K. Desler, G. Drews, M. Flasiński, D.J. Gilkinson, C. Glasman, P. Göttlicher, J. Große-Knetter, T. Haas, W. Hain, D. Hasell, H. Heßling, Y. Iga, K.F. Johnson, P. Joos, M. Kasemann, R. Klanner, W. Koch, U. Kötz, H. Kowalski, J. Labs, A. Ladage, B. Löhr, M. Löwe, D. Lüke, J. Mainusch, O. Mańczak, J. Milewski, T. Monteiro, J.S.T. Ng, D. Notz, K. Ohrenberg, K. Piotrzkowski, M. Roco, M. Rohde, J. Roldán, U. Schneekloth, W. Schulz, F. Selonke, B. Surrow, T. Voß, D. Westphal, G. Wolf, U. Wollmer, C. Youngman, W. Zeuner, H.J. Grabosch, A. Kharchilava, S.M. Mari, A. Meyer, S. Schlenstedt, N. Wulff, G. Barbagli, E. Gallo, P. Pelfer, G. Maccarrone, S. De Pasquale, L. Votano, A. Bamberger, S. Eisenhardt, T. Trefzger, S. Wölfle, J.T. Bromley, N.H. Brook, P.J. Bussey, A.T. Doyle, D.H. Saxon, L.E. Sinclair, M.L. Utley, A.S. Wilson, A. Dannemann, U. Holm, D. Horstmann, R. Sinkus, K. Wick, B.D. Burow, L. Hagge, E. Lohrmann, G. Poelz, W. Schott, F. Zetsche, T.C. Bacon, N. Brümmer, I. Butterworth, V.L. Harris, G. Howell, B.H.Y. Hung, L. Lamberti, K.R. Long, D.B. Miller, N. Pavel, A. Prinias, J.K. Sedgbeer, D. Sideris, A.F. Whitfield, U. Mallik, M.Z. Wang, S.M. Wang, J.T. Wu, P. Cloth, D. Filges, S.H. An, G.H. Cho, B.J. Ko, S.B. Lee, S.W. Nam, H.S. Park, S.K. Park, S. Kartik, H.-J. Kim, R.R. McNeil, W. Metcalf, V.K. Nadendla, F. Barreiro, J.P. Fernandez, R. Graciani, J.M. Hernández, L. Hervás, L. Labarga, M. Martinez, J. del Peso, J. Puga, J. Terron, J.F. de Trocóniz, F. Corriveau, D.S. Hanna, J. Hartmann, L.W. Hung, J.N. Lim, C.G. Matthews, P.M. Patel, M. Riveline, D.G. Stairs, M. St-Laurent, R. Ullmann, G. Zacek, T. Tsurugai, V. Bashkirov, B.A. Dolgoshein, A. Stifutkin, G.L. Bashindzhagyan, P.F. Ermolov, L.K. Gladilin, Yu.A. Golubkov, V.D. Kobrin, I.A. Korzhavina, V.A. Kuzmin, O.Yu. Lukina, A.S. Proskuryakov, A.A. Savin, L.M. Shcheglova, A.N. Solomin, N.P. Zotov, M. Botje, F. Chlebana, J. Engelen, M. de Kamps, P. Kooijman, A. Kruse, A. van Sighem, H. Tiecke, W. Verkerke, J. Vossebeld, M. Vreeswijk, L. Wiggers, E. de Wolf, R. van Woudenberg, D. Acosta, B. Bylsma, L.S. Durkin, J. Gilmore, C. Li, T.Y. Ling, P. Nylander, I.H. Park, T.A. Romanowski, D.S. Bailey, R.J. Cashmore, A.M. Cooper-Sarkar, R.C.E. Devenish, N. Harnew, M. Lancaster, L. Lindemann, J.D. McFall, C. Nath, V.A. Noyes, A. Quadt, J.R. Tickner, H. Uijterwaal, R. Walczak, D.S. Waters, F.F. Wilson, T. Yip, A. Bertolin, R. Brugnera, R. Carlin, F. Dal Corso, M. De Giorgi, U. Dosselli, S. Limentani, M. Morandin, M. Posocco, L. Stanco, R. Stroili, C. Voci, F. Zuin, J. Bulmahn, R.G. Feild, B.Y. Oh, J.J. Whitmore, G. D'Agostini, G. Marini, A. Nigro, E. Tassi, J.C. Hart, N.A. McCubbin, T.P. Shah, E. Barberis, T. Dubbs, C. Heusch, M. Van Hook, W. Lockman, J.T. Rahn, H.F.-W. Sadrozinski, A. Seiden, D.C. Williams, J. Biltzinger, R.J. Seifert, O. Schwarzer, A.H. Walenta, G. Zech, H. Abramowicz, G. Briskin, S. Dagan, A. Levy, J.I. Fleck, M. Inuzuka, T. ishii, M. Kuze, S. Mine, M. Nakao, I. Suzuki, K. Tokushuku, K. Umemori, S. Yamada, Y. Yamazaki, M. Chiba, R. Hamatsu, T. Hirose, K. Homma, S. Kitamura, T. Matsushita, K. Yamauchi, R. Cirio, M. Costa, M.I. Ferrero, S. Maselli, C. Peroni, R. Sacchi, A. Solano, A. Staino, M. Dardo, D.C. Bailey, F. Benard, M. Brkic, C.-P. Fagerstroem, G.F. Hartner, K.K. Joo, G.M. Levman, J.F. Martin, R.S. Orr, S. Polenz, C.R. Sampson, D. Simmons, R.J. Teuscher, J.M. Butterworth, C.D. Catterall, T.W. Jones, P.B. Kaziewicz, J.B. Lane, R.L. Saunders, J. Shulman, M.R. Sutton, B. Lu, L.W. Mo, W. Bogusz, J. Ciborowski, J. Gajewski, G. Grzelak, M. Kasprzak, M. Krzyżanowski, K. Muchorowski, R.J. Nowak, J.M. Pawlak, T. Tymieniecka, A.K. Wróblewski, J.A. Zakrzewski, A.F. Żarnecki, M. Adamus, C. Coldewey, Y. Eisenberg, D. Hochman, U. Karshon, D. Revel, D. Zer-Zion, W.F. Badgett, J. Breitweg, D. Chapin, R. Cross, S. Dasu, C. Foudas, R.J. Loveless, S. Mattingly, D.D. Reeder, S. Silverstein, W.H. Smith, A. Vaiciulis, M. Wodarczyk, S. Bhadra, M.L. Cardy, W.R. Frisken, M. Khakzad, W.N. Murray, W.B. Schmidke, and ZEUS at HERA (IHEF, IoP, FNWI)
Subjects: Nuclear and High Energy Physics, Particle physics, COLLISIONS, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, FOS: Physical sciences, Jet (particle physics), PPBAR COLLIDER, PROTON, 01 natural sciences, 7. Clean energy, law.invention, CROSS-SECTIONS, High Energy Physics - Experiment, Nuclear physics, EVENTS, High Energy Physics - Experiment (hep-ex), GAMMA-P INTERACTIONS, MONTE-CARLO, law, 0103 physical sciences, Invariant mass, 010306 general physics, Collider, Nuclear Experiment, Quantum chromodynamics, Physics, ZEUS (particle detector), 010308 nuclear & particles physics, High Energy Physics::Phenomenology, ZEUS, ZEUS BARREL CALORIMETER, HERA, Rest frame, Gluon, PARTON DISTRIBUTIONS, HARD SCATTERING, High Energy Physics::Experiment
Abstract: Jet photoproduction, where the two highest transverse energy ($\ETJ$) jets have $\ETJ$ above 6 GeV and a jet-jet invariant mass above 23~GeV, has been studied with the ZEUS detector at the HERA $ep$ collider. Resolved and direct photoproduction samples have been separated. The cross section as a function of the angle between the jet-jet axis and the beam direction in the dijet rest frame has been measured for the two samples. The measured angular distributions differ markedly from each other. They agree with the predictions of QCD calculations, where the different angular distributions reflect the different spins of the quark and gluon exchanged in the hard subprocess., 20 pages including 4 figures

13. Study of D* (2010)± production in ep collisions at HERA

Author: A. Nigro, Yasunori Yamazaki, J. Kochocki, B. Gutjahr, H. Hultschig, John Hart, L. M. Shcheglova, A. Prinias, D. Haun, E. Barberis, A. N. Solomin, U. Mallik, R. R. McNeil, K. Desler, M. Lancaster, W. Koch, F. Selonke, E. Hilger, A.F. Whitfield, S.M. Mari, J.T. Wu, K. Charchuła, Giuseppe Iacobucci, M. Krzyżanowski, W. Metcalf, H. Beier, Tadeusz Kowalski, J. Große-Knetter, A. Bruni, D. Daniels, U. Holm, B.Y. Oh, M. Löwe, Y Zhang, D.D. Reeder, B. Diekmann, M. Wodarczyk, G. Poelz, J. Mollen, J. Zaja̧c, P. B. Kaziewicz, L. Köpke, L. Lamberti, H. Uijterwaal, Lutz Feld, J. J. Whitmore, C. Li, Rosario Nania, Sung Keun Park, Nicolo Cartiglia, N. Pavel, I. Suzuki, G.R. Smith, Krzysztof Piotrzkowski, P. Bruni, Costas Foudas, J.F. Zhou, Christian Nemoz, Giancarlo Susinno, Vladimir Bashkirov, L.W. Mo, K. K. Joo, Y. Iga, Cristiana Peroni, N. Dyce, A. Meyer, G. Briskin, Mariusz Przybycien, M. Corradi, Tobias M. Haas, William S. Lockman, G. Grzelak, Matthias Kasemann, K. M. Furutani, D. Westphal, D. Notz, R. J. Cashmore, S. Nickel, M. Derrick, D. B. Miller, C. Voci, B. Surrow, S.H. An, T. Tymieniecka, M. Zachara, S. Mengel, J. Mainusch, D. Schramm, C. A. Heusch, Ada Solano, R. S. Orr, R.S. Gilmore, H.J. Grabosch, S. H. Yon, T. W. Jones, Anna Goussiou, G. L. Bashindzhagyan, N. P. Zotov, W.B. Schmidke, R. J. Teuscher, Shoichi Yamada, R.C.E. Devenish, Avto Kharchilava, W. Schott, Cd Catterall, T. C. Bacon, U. Kötz, A. Dannemann, H.G.J.M. Tiecke, F. Benard, O. Mańczak, G. F. Hartner, Roberto Carlin, Q. Zhu, I. Fleck, U. Karshon, J.B. Lane, Gy. Wolf, Rr Rau, J.A. O'Mara, Marcel Vreeswijk, S. Limentani, Kenneth Long, K. Wick, S. De Pasquale, Luis Hervas, S. Ritz, D. Boscherini, Marco Schioppa, S. Magill, J. Gajewski, B. Behrens, O. Deppe, T. Doeker, A. Caldwell, M. Roco, J.D. McFall, V. K. Nadendla, R. J. Nowak, G. Bari, G. Laurenti, J. Del Peso, P. G. Pelfer, J. Repond, Masashi Hazumi, G. Castellini, R.L. Talaga, T. Tsurugai, K. Ohrenberg, M. Van Hook, L.E. Sinclair, S.S. Wilson, P. Luffman, A. Frey, A. Bertolin, B. Bednarek, P.F. Ermolov, C. Rembser, J. Bulmahn, K.W. McLean, P.B. Straub, H. Zhang, H.-P. Jakob, A. Ladage, S. Söldner-Rembold, K. Homma, Samuel Silverstein, R. L. Saunders, J. F. Martin, M.B. Crombie, R. Seidlein, E. Lohrmann, J.S.T. Ng, M. Basile, W. H. Smith, P. Giusti, M. Brkic, E. Badura, D. Zer-Zion, J. F. de Trocóniz, L. Zawiejski, Roberto Cirio, A. Byrne, Fernando Barreiro, Robert Stanek, A. Mass, N. Wulff, P. Joos, J. Stamm, F. Zetsche, E. Stiliaris, K. Eskreys, I. Gialas, M.C.K. Mattingly, L. S. Durkin, R. Yoshida, L. Wai, J. Schroeder, R. Brugnera, R. Hamatsu, J. Puga, N. A. McCubbin, V. A. Kuzmin, D. C. Bailey, Cg Matthews, Luca Stanco, Mário Costa, D. Hasell, G. Zacek, Mauro Morandin, G. D'Agostini, M. Z. Wang, B. Foster, S. Bhadra, J. K. Sedgbeer, R. Imlay, L. W. Hung, T. Y. Ling, T. Yip, Jens Hartmann, L. Iannotti, M. De Giorgi, C. Youngman, Y. Zamora Garcia, V. D. Kobrin, T. Dubbs, Y. Nakamitsu, Katsuo Tokushuku, T.P. Shah, S. M. Wang, Ulf Behrens, F.S. Chlebana, Federico Cindolo, W. Bogusz, S. Eisenhardt, W. Hain, L. Lindemann, G. Bruni, Simon George, Umberto Dosselli, R. J. Seifert, Giovanni Abbiendi, I. H. Park, Tachishige Hirose, D. H. Saxon, T. Voß, A. Bargende, J. M. Pawlak, G.A. Blair, Leszek Adamczyk, M.I. Ferrero, M. Adamus, G. Marini, A.K. Wróblewski, A. Bamberger, Masami Chiba, D. Mikunas, Janusz Chwastowski, Klaus Kurt Desch, Luisa Cifarelli, A. M. Cooper-Sarkar, L. K. Gladilin, Neville Harnew, S. Dagan, W. Schulz, Robert Klanner, A. Vaiciulis, E. Tassi, Gm Levman, Djp Norman, I. Ali, Ben Bylsma, J. Milewski, A. Quadt, E. A. De Wolf, J. Biltzinger, H. Hartmann, D. S. Bailey, M. Khakzad, M. L. Cardy, P. Göttlicher, K. Honscheid, Yu. A. Golubkov, Y. Eisenberg, M.A.J. Botje, R. G. Feild, D. Krakauer, K. Yamauchi, H. Kowalski, M. Eckert, L. Bellagamba, M. St.Laurent, E. Paul, D.J. Gilkinson, M. Kuze, F. Dal Corso, S. Kartik, E. Rulikowska-Zarȩbska, Douglas Gingrich, Francois Corriveau, R. Walczak, H. F.W. Sadrozinski, Ricardo Graciani, K. Heinloth, Giuseppe Barbagli, L. Hagge, F. Sciulli, D. Revel, T. Hasegawa, J. Roldán, Roberto Sacchi, A. Leich, C. Glasman, B. Hubbard, C. P. Fagerstroem, F. Palmonari, A. Stifutkin, Sridhara Dasu, S. Mine, S Campbell-Robson, Halina Abramowicz, A.S. Proskuryakov, Giuseppe Levi, K. Muchorowski, W.F. Badgett, K. Jelen, T. Ishii, A. Kotański, L.A.T. Bauerdick, T.L. Short, R.J. Tapper, Amedeo Staiano, U. F. Katz, A. Freidhof, B. Lu, M. Posocco, W.R. Frisken, G. Sartorelli, Aharon Levy, T.J. Llewellyn, J. N. Lim, J. M. Hernandez, Debades Bandyopadhyay, J. K. Bienlein, R. van Woudenberg, G.P. Heath, M. de Kamps, B. Musgrave, D. Filges, R. Sinkus, S. W. Nam, R. Stroili, Antonino Zichichi, A. Bernstein, J.J. Engelen, P.M. Kooijman, U. Schneekloth, H. J. Kim, R. Wedemeyer, Giovanni Maccarrone, Thomas Trefzger, S. Schlenstedt, P. J. Bussey, A. Cassidy, I. Butterworth, M. Nakahata, D. S. Hanna, M. L. Utley, S. M. Hong, E. Gallo, Andrea Contin, James Crittenden, S. Yang, A. Kruse, Anselmo Margotti, P. Cloth, L.W. Wiggers, K. Prytz, Danuta Kisielewska, Ta Romanowski, T. Massam, E. McCliment, Y. Nagasawa, R. Ayad, H.F. Heath, G. Cases, T. Neumann, B. Löhr, A. Seiden, F. F. Wilson, J. A. Zakrzewski, M. Grothe, C.J.S. Morgado, Michele Arneodo, S. Kitamura, J. Ciborowski, M. Chiarini, J.A. Parsons, R. Ullmann, J. Shulman, Juan Terron, M. Kasprzak, Jonathan Butterworth, G. Cara Romeo, C. Fordham, A. Eskreys, Lucia Votano, A. T. Doyle, L. Labarga, Wouter Verkerke, C. Nath, H. Heßling, G. Geitz, B. Y. H. Hung, A. A. Savin, B. D. Burow, W.N. Murray, G. Anzivino, M. Nakao, P. Borzemski, G. Drews, G. Zech, M. Flasiński, R. Schattevoy, A.S. Wilson, M. Dardo, C. Coldewey, L. Suszycki, A. H. Walenta, B. A. Dolgoshein, P. Morawitz, Aleksander Filip Żarnecki, Silvia Maselli, D. Lüke, A. Polini, D. Acosta, Dg Stairs, D. Horstmann, R. Timellini, A. Dake, N. H. Brook, V. L. Harris, M. Rohde, R. Loveless, J. Labs, M. H. Suh, M. Geerts, K. Blankenship, C.R. Sampson, Jeffrey T. Rahn, P. M. Patel, V.A. Noyes, and Zeus (IHEF, IoP, FNWI)
Subjects: Nuclear and High Energy Physics, Particle physics, Meson, Proton, LUND MONTE-CARLO, photoproduction, charmed meson production, FOS: Physical sciences, 01 natural sciences, Zeus (malware), JET FRAGMENTATION, Charm quark, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), CHARM PHOTOPRODUCTION, GAMMA-P INTERACTIONS, 0103 physical sciences, Charm (quantum number), 010306 general physics, Quantum chromodynamics, Physics, ZEUS, LEADING-ORDER QCD, PARTON DISTRIBUTIONS, CROSS-SECTION, HARD SCATTERING, HEAVY QUARKS, E+E-PHYSICS, 010308 nuclear & particles physics, HERA, Gluon
Abstract: We report the first observation of charmed mesons with the ZEUS detector at HERA using the decay channel ${\rm D}^{*+}\rightarrow (\Do \rightarrow {\rm K}^-\pi^+)\pi^+$ (+ c.c.). Clear signals in the mass difference $\Delta M$=$M$(D$^*$)--$M$(D$^0)$ as well as in the $M(K\pi)$ distribution at the D$^0$ mass are found. The $ep$ cross section for inclusive \DSpm\ production with $Q^2, Comment: 19 pages, latex, 3 figures appended as uuencoded file

14. The influence of terpinen-4-ol and eucalyptol - The essential oil components - on fungi and plant sterol monolayers.

Author: Połeć K, Wójcik A, Flasiński M, Wydro P, Broniatowski M, and Hąc-Wydro K
Subjects: Microscopy methods, Surface Properties, X-Ray Diffraction methods, Eucalyptol chemistry, Fungi chemistry, Oils, Volatile chemistry, Phytosterols chemistry, Sterols chemistry, Terpenes chemistry
Abstract: Antifungal and herbicidal activity of terpenes, being the components of the essential oils, is directly related to the incorporation of these compounds into cellular membranes. Thus, the differences in the lipid composition of various pathogenic membranes may be the factor determining the activity of these molecules. One of the class of lipids, which form the membrane environment are sterols. The aim of this work was to compare the effect of two terpenes: terpinen-4-ol and eucalyptol on the monolayers formed by ergosterol and β - sitosterol, which are the components of fungi and plant membranes, respectively. The modifications in the sterol monolayer properties were investigated in the surface pressure-area measurements and penetration studies as well as in a micrometer scale (Brewster angle microscopy experiments) and in nanoscale (GIXD technique). It was evidenced that although at higher surface pressure the terpene molecules are in part removed from the interface, they are able to substantially modify the condensation, morphology and molecular organization of the sterol film. It was also found that the incorporation of terpenes into sterol films is comparable for both sterols, however, β - sitosterol monolayers properties are affected more strongly than ergosterol films. Finally, the analysis of the results of the studies performed on model membrane systems and the results of antimicrobial studies reported in literature, enabled us to suggest that the activity of terpenes depends on the membrane composition and that the sterol concentration may be important from the point of view of antifungal effect of terpinen-4-ol and eucalyptol., (Copyright © 2019 Elsevier B.V. All rights reserved.)
Published: 2019
Full Text: View/download PDF

15. Interactions of Long-Chain Perfluorotelomer Alcohol and Perfluorinated Hydrocarbons with Model Decomposer Membranes.

Author: Wójcik A, Perczyk P, Wydro P, Flasiński M, and Broniatowski M
Subjects: Microscopy, Phospholipids chemistry, Thermodynamics, X-Ray Diffraction, Fluorocarbons chemistry, Hydrocarbons, Fluorinated chemistry, Lipid Bilayers chemistry
Abstract: Perfluorinated hydrocarbons and their polar derivatives are produced annually in high quantities and find multiple industrial and technological applications due to their chemical and physical durability, significant hydro- and lipophobicity and excellent surface activity. Unfortunately, multiple perfluorinated compounds are recognized as persistent organic pollutants as they are completely nonbiodegradable and accumulate in soils and sediments. In our studies, we applied Langmuir monolayers formed by different structural phospholipids as models of soil bacteria and fungi membranes and investigated the effects exerted by long-chain perfluorinated pollutants, perfluorotelomer alcohol and two structurally different perfluorinated hydrocarbons, on the artificial membranes. Various mutually complemental methods such as surface pressure-mean molecular area isotherm registration, Brewster angle microscopy (BAM), and grazing incidence X-ray diffraction (GIXD) were applied. It turned out that the presence of the perfluorinated chemicals profoundly affected the phospholipid monolayers. The miscibility of the phospholipid with the perfluorotelomer alcohol depended strongly on the size and charge of the polar headgroup. Additionally, it was observed by BAM that the presence of the perfluorinated molecules significantly changed the texture of all the investigated phospholipid monolayers. On the basis of the BAM and GIXD results and other studies described in the scientific literature, we postulated that the perfluorinated hydrocarbons form an additional monolayer anchored on top of the phospholipid film. Our studies prove that both polar and nonpolar perfluorinated pollutants can be toxic to decomposer organisms and that their toxicity is strictly correlated with the phospholipid composition of the cellular membrane.
Published: 2018
Full Text: View/download PDF

16. Influence of Cationic Phosphatidylcholine Derivative on Monolayer and Bilayer Artificial Bacterial Membranes.

Author: Mach M, Węder K, Hąc-Wydro K, Flasiński M, Lewandowska-Łańcucka J, Wójcik K, and Wydro P
Subjects: Cations, Liposomes chemistry, Membrane Lipids chemistry, Cell Membrane drug effects, Membranes, Artificial, Phosphatidylcholines chemistry, Phosphatidylcholines pharmacology
Abstract: An increasing number of bacterial infections and the rise in antibiotic resistance of a number of bacteria species forces one to search for new antibacterial compounds. The latter facts motivate the investigations presented herein and are aimed at studying the influence of a cationic lipid, 1-palmitoyl-2-oleoyl- sn-glycero-3-ethylphosphocholine (EPOPC), on model (mono- and bilayer) membranes. The monolayer experiments involved the analysis of the interactions of EPOPC with bacterial membrane lipids in one component and mixed systems as well as Brewster angle microcopy studies. The properties of liposomes were analyzed based on the results of dynamic light scattering (DLS) and zeta potential measurements as well as on the experiments concerning the release of calcein entrapped in liposomes after titration with surfactant solution and steady-state fluorescence anisotropy of DPH. The obtained results evidenced that EPOPC, even at low concentrations, strongly changes organization of model systems making them less condensed. Moreover, EPOPC decreases the hydrodynamic diameter of liposomes, increases their zeta potential, and destabilizes model membranes, increasing their fluidity and permeability. Also, the in vitro tests performed on Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) strains prove that EPOPC has some bacteriostatic properties which seem to be stronger toward Gram-negative than Gram-positive bacteria. All these findings allow one to conclude that EPOPC mode of action may be directly connected with the interactions of EPOPC molecules with bacterial membranes.
Published: 2018
Full Text: View/download PDF

17. Influence of Parabens on Bacteria and Fungi Cellular Membranes: Studies in Model Two-Dimensional Lipid Systems.

Author: Flasiński M, Kowal S, Broniatowski M, and Wydro P
Subjects: Candida albicans cytology, Models, Molecular, Molecular Structure, Particle Size, Pseudomonas aeruginosa cytology, Staphylococcus aureus cytology, Surface Properties, Candida albicans chemistry, Cell Membrane chemistry, Lipids chemistry, Parabens chemistry, Pseudomonas aeruginosa chemistry, Staphylococcus aureus chemistry
Abstract: Langmuir monolayers were used to study the influence of four commercially applied parabens on multicomponent systems composed of lipid species characteristic of the cellular membrane of microorganisms found in carbohydrates and proteins reaching products, including food and cosmetics. The aim of the undertaken studies was to shed new light on the problem of parabens' interactions with membrane lipids and their affinity for monolayers differing with regard to the composition, mutual lipid ratios, and physicochemical properties. The discussion is based on the π-A isotherm characteristics, surface morphology observation performed with BAM, and analysis of the diffraction data collected for the periodically ordered lipid domains present in the investigated multicomponent films. Our studies revealed that the selected parabens are capable of surface film modification and that the magnitude of this effect increases with the number of methylene groups in the ester part of paraben molecules. We found that the strongest destructive effect was observed for model 1 (Staphylococcus aureus), a lower effect was observed for model 2 (Pseudomonas aeruginosa), and the lowest effect was observed for model 3 (Candida albicans). It was inferred that such a trend appears due to the composition of the artificial membranes, i.e., above all, in the presence or lack of sterol molecules and the content of negatively charged lipids.
Published: 2018
Full Text: View/download PDF

18. Polycyclic aromatic hydrocarbons in model bacterial membranes - Langmuir monolayer studies.

Author: Broniatowski M, Binczycka M, Wójcik A, Flasiński M, and Wydro P
Subjects: 1,2-Dipalmitoylphosphatidylcholine analogs & derivatives, 1,2-Dipalmitoylphosphatidylcholine chemistry, Bacteria drug effects, Bacteria growth & development, Cardiolipins chemistry, Cell Membrane chemistry, Kinetics, Phosphatidylethanolamines chemistry, Phosphatidylglycerols chemistry, Polycyclic Aromatic Hydrocarbons toxicity, Soil Pollutants toxicity, Structure-Activity Relationship, Thermodynamics, Cell Membrane drug effects, Polycyclic Aromatic Hydrocarbons chemistry, Soil Pollutants chemistry, Unilamellar Liposomes chemistry
Abstract: High molecular weight polycyclic aromatic hydrocarbons (HMW-PAHs) are persistent organic pollutants which due to their limited biodegradability accumulate in soils where their increased presence can lead to the impoverishment of the decomposer organisms. As very hydrophobic PAHs easily penetrate cellular membranes of soil bacteria and can be incorporated therein, changing the membrane fluidity and other functions which in consequence can lead to the death of the organism. The structure and size of PAH molecule can be crucial for its membrane activity; however the correlation between PAH structure and its interaction with phospholipids have not been investigated so far. In our studies we applied phospholipid Langmuir monolayers as model bacterial membranes and investigated how the incorporation of six structurally different PAH molecules change the membrane texture and physical properties. In our studies we registered surface pressure and surface potential isotherms upon the monolayer compression, visualized the monolayer texture with the application of Brewster angle microscopy and searched the ordering of the film-forming molecules with molecular resolution with the application of grazing incidence X-ray diffraction (GIXD) method. It turned out that the phospholipid-PAH interactions are strictly structure dependent. Four and five-ring PAHs of the angular or cluster geometry can be incorporated into the model membranes changing profoundly their textures and fluidity; whereas linear or large cluster PAHs cannot be incorporated and separate from the lipid matrix. The observed phenomena were explained based on structural similarities of the applied PAHs with membrane steroids and hopanoids., (Copyright © 2017. Published by Elsevier B.V.)
Published: 2017
Full Text: View/download PDF

19. Essential oils as food eco-preservatives: Model system studies on the effect of temperature on limonene antibacterial activity.

Author: Hąc-Wydro K, Flasiński M, and Romańczuk K
Subjects: Cyclohexenes, Limonene, Temperature, Terpenes, Anti-Bacterial Agents analysis, Food Preservatives analysis, Membranes, Artificial, Oils, Volatile analysis
Abstract: Antimicrobial properties of essential oils predestine these substances to be used as ecological food preservatives. However, their activity is determined by variety of factors among which external conditions and food properties are highly important. Herein the influence of limonene on artificial membranes was studied to verify the effect of temperature on the incorporation of this compound into model bacterial membrane. The investigations were done on lipid monolayers and the experiments involved the surface pressure-area measurements, penetration studies and Brewster Angle Microscopy analysis. It was found that limonene incorporates into lipid monolayers causing their fluidization. However, the magnitude of alterations depends on limonene concentration, model membrane composition and, for a given composition, on system condensation. Moreover, the influence of limonene is stronger at lower temperatures and, in the light of collected data, this may be a consequence of strong volatility and evaporation of limonene increasing with temperature., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
Published: 2017
Full Text: View/download PDF

20. Studies on the Behavior of Eucalyptol and Terpinen-4-ol-Natural Food Additives and Ecological Pesticides-in Model Lipid Membranes.

Author: Hąc-Wydro K, Flasiński M, Broniatowski M, and Sołtys M
Subjects: Food Additives, Lipids, Membranes, Artificial, Pesticides, Terpenes, Eucalyptol chemistry
Abstract: Effective application of the essential oils requires detailed exploration of their mechanism of action and the origin of diverse activity of their components. In this work, the influence of eucalyptol and terpinen-4-ol on artificial membranes was studied to verify whether the differences in the activity of these compounds are related to their effect on membranes. The properties of monolayers formed from structurally different lipids in the presence of terpenes were examined based on the results of the surface pressure-area measurements, penetration studies, and Brewster angle microscopy experiments. Both compounds were able to incorporate into the membrane and alter lipid/lipid interactions, making the monolayer less stable and more fluid. These effects were determined by monolayer composition (but not by its condensation per se) and the resulting rheological properties and were stronger in the presence of terpinen-4-ol. These findings confirm the hypothesis that differences in the antimicrobial potency of these terpenes are membrane-related, and membrane composition may determine their selectivity.
Published: 2017
Full Text: View/download PDF

21. Phytohormone Behavior in the Model Environment of Plant and Human Lipid Membranes.

Author: Flasiński M and Święchowicz P
Subjects: Dose-Response Relationship, Drug, Erythrocytes drug effects, Fibroblasts drug effects, HEK293 Cells, Humans, Indoleacetic Acids chemistry, Indoleacetic Acids pharmacology, Models, Molecular, Molecular Structure, Particle Size, Plant Leaves chemistry, Plant Roots chemistry, Solanum lycopersicum chemistry, Membrane Lipids chemistry, Phytochrome chemistry, Zea mays chemistry
Abstract: Interactions between three auxins (indole-3-acetic acid (IAA), 2-naphthoxyacetic acid (BNOA), and 2,4-dichlorophenoxyacetic acid (2,4-D)) and model two-dimensional lipid systems mimicking plant and human cell membranes were investigated in monolayers formed at the air/water solution interface. The analysis was based on the recorded π-A isotherm characteristics complemented with Brewster angle microscopy. The influence of auxins on model membranes was discussed on the basis of condensation changes, modification of mutual lipid-lipid interactions in the mixed films, and morphological alteration of the surface domains on the microscopic scale. It was demonstrated that the lipid composition and mutual proportion of the artificial membranes together with sterol to main the phospholipid ratio play a crucial role in the context of auxin behavior in the membrane-mimicking environment. Apart from specific molecular interactions between studied phytohormones represented by auxins and lipids, the condensation of the investigated monolayers was found to be a regulative factor of model systems' susceptibility toward auxin action. Two effects were recognized: fluidizing of monolayers being in the liquid state (model membranes) and initialization of the three-dimensional structure formation in ordered sterol films at high surface pressure. The influence of auxin molecules on lipid interactions in the monolayer and diminishing of the film condensation was the largest for BNOA, due to the presence of the most bulky nonpolar, aromatic fragment in the molecule. It was also demonstrated that auxins interact with model plant membranes more selectively, stronger, and at markedly lower concentration than with the human membrane models.
Published: 2017
Full Text: View/download PDF

22. Sterol-Phospholipid Hybrids at the Air/Water Interface: Studies on Properties and Interactions with Parent Lipid Molecules.

Author: Flasiński M, Konderla B, Broniatowski M, and Wydro P
Abstract: The two synthetic sterol-phospholipid hybrids DCholPC and PCholPC were investigated in monolayers at the air/water interface. Study was based on π-A isotherm analysis complemented with application of grazing incidence X-ray diffraction. It was found that both compounds are capable of forming stable, highly condensed monolayers of a surface characteristics typical for sterols. GIXD studies show that the crystallographic area for DCholPC monolayer is very similar to that found for cholesterol (37.1 vs 38.0 Å(2)), while for PCholPC (28.8 Å(2)) it is significantly smaller as compared to area for the mixed Chol/DPPC 2/1 monolayer (33.4 Å(2)). In our study the problem of interactions between investigated sterol-phospholipid hybrids and natural membrane lipid components was for the first time analyzed in planar lipid systems. Studies on mixed monolayers showed that both hybrids, similarly to cholesterol, reveal a condensing effect toward DPPC acyl chains; however, DCholPC having two steroid moieties in the molecule was found to be more efficient. On the other hand, the sterol moiety and the hydrocarbon chain of PCholPC molecule are packed in the 2D crystalline phase extremely tight. Our studies showed that the investigated compounds can be applied as biocompatible components of stable liposomes.
Published: 2016
Full Text: View/download PDF

23. Studies on the interactions of bisphenols with anionic phospholipids of decomposer membranes in model systems.

Author: Broniatowski M, Sobolewska K, Flasiński M, and Wydro P
Subjects: Anions chemistry, Benzhydryl Compounds toxicity, Estrogens toxicity, Humans, Hydrophobic and Hydrophilic Interactions, Models, Chemical, Phenols toxicity, Phospholipids chemistry, Benzhydryl Compounds chemistry, Cell Membrane chemistry, Environmental Pollution, Estrogens chemistry, Phenols chemistry
Abstract: Bisphenol A (BPA) and other bisphenols constitute a class of organic pollutants, which because of their estrogenic properties, low dose activity and bioaccumulation pose considerable risk for public health as well as for the environment. Accumulated in the sediment bisphenols can endanger the decomposers' populations being incorporated into their cellular membranes; however, the mechanism of their membrane activity is unknown. Therefore, to study these phenomena we applied anionic phospholipid Langmuir monolayers as simple but versatile models of decomposers biomembranes. Phosphatidylglycerols and cardiolipins are not only the main components of bacterial membranes but also of crucial importance in mitochondrial and thylakoid membranes in eukaryotic cells. In our investigations we applied five compounds of the bisphenol class most commonly detected in the environment. To characterize the bisphenols-model membrane interactions we applied multiple mutually independent methods of physical chemistry; namely: the Langmuir monolayer technique, surface potential measurements, Brewster angle microscopy for the visualization of the monolayers' texture and grazing incidence X-ray diffraction for the discussion of the phospholipids packing within the monolayers. Our studies indicated that all the investigated bisphenols interact with the model membrane, but the strength of the interactions is dependent on the bisphenol structure and hydrophobicity and the fluidity of the model membranes. We proved that bisphenol S often treated as the least toxic BPA analog can also be incorporated to the model membranes changing their structure and fluidity., (Copyright © 2016 Elsevier B.V. All rights reserved)
Published: 2016
Full Text: View/download PDF

24. Studies on the interactions between parabens and lipid membrane components in monolayers at the air/aqueous solution interface.

Author: Flasiński M, Gawryś M, Broniatowski M, and Wydro P
Subjects: Air, Animals, Cell Membrane metabolism, Molecular Conformation, Parabens metabolism, Phospholipids metabolism, Pressure, Surface Properties, Water chemistry, Cell Membrane chemistry, Lipid Bilayers chemistry, Parabens chemistry, Phospholipids chemistry
Abstract: The interactions between parabens (PBs) and lipid components of mammalian and bacterial cell membranes were investigated in model systems of Langmuir monolayers. Me-, Et-, Pr- and Bu-paraben studied in this paper are frequently applied as cosmetics and food preservatives, since they possess broad antimicrobial activity. The mode of PB action is connected with their incorporation into the membrane of bacterial organisms, however; it is not known what is the role of the respective lipid species in this mechanism. This problem is crucial to understand the differences in paraben activity toward individual microorganisms and to shed the light onto the problem of PB cytotoxicity reported in studies on mammalian cells. In this paper, the mentioned aspects were investigated with application of the Langmuir monolayer technique complemented with BAM and GIXD. Our experiments revealed that the influence of PBs depends on their chemical structure, solution concentration and on the class of lipid. The strongest modification of the monolayer characteristics, leading to its collapse at low surface pressure, occurred in the presence of BuPB, having the largest chain. PBs interact preferentially with the monolayers possessing low degree of condensation, whereas for LC state, the effect was weaker and observed only as modification of the 2D unit cells. In the model systems, PBs interact with phospholipids characteristic for mammalian membranes (phosphatidylcholine) stronger than with bacterial (phosphatidylglycerol and cardiolipin). This strong influence of parabens on the model systems composed of animal lipids may explain cytotoxic activity of these preservatives., (Copyright © 2016 Elsevier B.V. All rights reserved)
Published: 2016
Full Text: View/download PDF

25. Characteristics of the influence of auxins on physicochemical properties of membrane phospholipids in monolayers at the air/aqueous solution interface.

Author: Flasiński M, Bartosik M, Kowal S, Broniatowski M, and Wydro P
Subjects: Air, Solutions, Thermodynamics, Water, X-Ray Diffraction, Indoleacetic Acids chemistry, Membrane Lipids chemistry, Phospholipids chemistry
Abstract: Interactions between representatives of plant hormones and selected membrane lipids have been studied in monolayers at the air/aqueous solutions interface with π-A isotherm analysis, microscopic visualization and grazing incidence X-ray diffraction technique (GIXD). Four phytohormones: indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), 2-naphthoxyacetic acid (BNOA) and 2,4-dichlorophenoxyacetic acid (2,4-D), belonging to the class of auxins differ as regards the chemical structure of the aromatic molecular fragment. The studied phospholipids have been chosen since they are omnipresent in the biological membranes of plant and animal kingdom. Our results revealed that both natural (IAA and IBA) and synthetic (2,4-D and BNOA) phytohormones modify the physicochemical characteristics of the investigated lipid monolayers. Auxins caused strong diminishing of the monolayer condensation, especially for DPPC and SOPE, which may be attributed to the phase transition in these monolayers. In the performed experiments the key step of auxins action occurs when the molecules interact with monolayers in the expanded state-when the space in the lipid head-group region is large enough to accommodate the molecules of water soluble auxins. The application of GIXD technique confirmed that auxin molecules are also present at the interface at higher surface pressure (30 mN/m). The obtained results showed that among the investigated auxins, the largest influence on the lipid monolayers occurred in the case of BNOA, which molecule possesses the largest aromatic fragment. In contrast, 2,4-D, having the smallest aryl group affects the studied lipid systems to the smallest extent., (Copyright © 2015 Elsevier B.V. All rights reserved.)
Published: 2015
Full Text: View/download PDF

26. Antagonistic effects of α-tocopherol and ursolic acid on model bacterial membranes.

Author: Broniatowski M, Flasiński M, and Hąc-Wydro K
Subjects: Cell Membrane drug effects, Drug Antagonism, Triterpenes chemistry, alpha-Tocopherol chemistry, Ursolic Acid, Cell Membrane chemistry, Escherichia coli drug effects, Escherichia coli ultrastructure, Membrane Lipids chemistry, Triterpenes pharmacology, alpha-Tocopherol pharmacology
Abstract: α-tocopherol (Toc), the most active component of vitamin E can exert antagonistic effects disabling the therapy of cancers and bacterial infections. Such antagonisms were observed also between Toc and bioactive pentacyclic triterpenes (PT) exhibiting anticancer and antibacterial properties. Both Toc and PT are water-insoluble membrane active substances. Thus, our idea was to emulate their interactions with model Escherichia coli membranes. E. coli inner membranes were selected for the experiments because their lipid composition is quite simple and well characterized and the two main components are phosphatidylethanolamine and phosphatidylglycerol. As a model of E. coli membranes we applied Langmuir monolayers formed by the E. coli total extract of polar lipids (Etotal) as well as by the main lipid components: phosphatidylethanolamine (POPE) and phosphatidylglycerol (ECPG). The antagonistic effects of ursolic acid (Urs) and Toc were investigated with the application of ternary Langmuir monolayers formed by Urs, Toc and one of the phospholipids POPE or ECPG. Our studies indicated that the affinities of Urs and Toc towards the POPE molecule are comparable; whereas there are profound differences in the interactions of Urs and Toc with ECPG. Thus, the model experiments prove that in the case of E. coli membrane, the differences in the interactions between Urs and Toc with the anionic bacterial phosphatidylglycerol can be the key factor responsible for the antagonistic effects observed between PT and Toc in vivo., (Copyright © 2015 Elsevier B.V. All rights reserved.)
Published: 2015
Full Text: View/download PDF

27. The influence of cholesterol precursor--desmosterol--on artificial lipid membranes.

Author: Hąc-Wydro K, Węder K, Mach M, Flasiński M, and Wydro P
Subjects: Cholesterol chemistry, Desmosterol metabolism, Molecular Structure, Phosphatidylcholines chemistry, Sphingomyelins chemistry, Structure-Activity Relationship, Desmosterol chemistry, Lipid Bilayers, Membranes, Artificial
Abstract: The disorders in cholesterol biosynthesis pathway and various diseases manifest in the accumulation of cholesterol precursors in the human tissues and cellular membranes. In this paper the effect of desmosterol--one of cholesterol precursors--on model lipid membranes was studied. The investigations were performed for binary SM/desmo and POPC/desmo and ternary SM/POPC/desmo monolayers. Moreover, the experiments based on the gradual substitution of cholesterol by desmosterol in SM/POPC/chol=1:1:1 system were done. The obtained results allowed one to conclude that desmosterol is of lower domains promoting and stabilizing properties and packs less tightly with the lipids in monolayers. Moreover, desmosterol probably could replace cholesterol in model membranes, but only at its low proportion in the system (2%), however, at a higher degree of cholesterol substitution a significant decrease of the monolayer stability and packing and alterations in the film morphology were detected. The results collected in this work together with those from previous experiments allowed one to analyze the effect of a double bond in the sterol side chain as well as its position in the ring system on membrane activity of the molecule and to verify Bloch hypothesis., (Copyright © 2015 Elsevier B.V. All rights reserved.)
Published: 2015
Full Text: View/download PDF

28. Crucial Role of the Double Bond Isomerism in the Steroid B-Ring on the Membrane Properties of Sterols. Grazing Incidence X-Ray Diffraction and Brewster Angle Microscopy Studies.

Author: Flasiński M, Wydro P, Broniatowski M, Hąc-Wydro K, and Fontaine P
Subjects: Isomerism, Models, Molecular, Molecular Conformation, Microscopy, Sterols chemistry, X-Ray Diffraction
Abstract: Three cholesterol precursors-desmosterol, zymosterol, and lanosterol-were comprehensively characterized in monolayers formed at the air/water interface. The studies were based on registration of the surface pressure (π)-area (A) isotherms complemented with in situ analysis performed with application of modern physicochemical techniques: grazing incidence X-ray diffraction (GIXD) and Brewster angle microscopy (BAM). In this approach we were interested in the correlation between molecular structures of the studied sterols found in the cholesterol biosynthetic pathway and their membrane properties. Our results revealed that only desmosterol behaves in Langmuir monolayers comparably to cholesterol, the molecules of which arrange in the monolayers into a hexagonal lattice, while the two remaining sterols possess extremely different properties. We found that molecules of both zymosterol and lanosterol are organized on the water surface in the two-dimensional oblique unit cells despite the fact that they are oriented perpendicular to the monolayer plane. The comparison of chemical structures of the investigated sterols leads to the conclusion that the only structural motive that can be responsible for such unusual behavior is the double bond in the B sterol ring, which is located in desmosterol in a different position from in the other two sterols. This issue, which was neglected in the scientific literature, seems to have crucial importance for sterol activity in biomembranes. We showed that this structural modification in sterol molecules is directly responsible for their adaptation to proper functioning in biomembranes.
Published: 2015
Full Text: View/download PDF

29. The studies on the toxicity mechanism of environmentally hazardous natural (IAA) and synthetic (NAA) auxin--The experiments on model Arabidopsis thaliana and rat liver plasma membranes.

Author: Hąc-Wydro K and Flasiński M
Subjects: Animals, Arabidopsis chemistry, Arabidopsis metabolism, Cell Membrane chemistry, Cell Membrane metabolism, Dose-Response Relationship, Drug, Environmental Pollutants metabolism, Indoleacetic Acids metabolism, Liver chemistry, Liver metabolism, Membrane Lipids chemistry, Membrane Lipids metabolism, Microscopy methods, Naphthaleneacetic Acids metabolism, Plant Growth Regulators metabolism, Plant Growth Regulators toxicity, Rats, Cell Membrane drug effects, Environmental Pollutants toxicity, Indoleacetic Acids toxicity, Naphthaleneacetic Acids toxicity
Abstract: This paper concerns the studies towards membrane-damage effect of two auxins: indole-3-acetic acid - IAA and 1-naphthaleneacetic acid - NAA on plant (Arabidopsis thaliana) and animal (rat liver) model membranes. The foregoing auxins are plant growth regulators widely used in agriculture to control the quality of the crop. However, their accumulation in the environment makes them hazardous for the living organisms. The aim of our investigations was to compare the effect of natural (IAA) vs. synthetic (NAA) auxin on the organization of plant and animal model membranes and find a possible correlation between membrane-disturbing effect of these compounds and their toxicity. The collected data evidenced that auxins cause destabilization of membranes, decrease their condensation and weakens interactions of molecules. The alterations in the morphology of model systems were also noticed. The foregoing effects of auxins are concentration-dependent and additionally NAA was found to act on animal vs. plant membranes more selectively than IAA. Interestingly, both IAA and NAA induce the strongest disordering in model lipid system at the concentration, which is frequently reported as toxic to animal and plants. Based on the above findings it was proposed that membrane-damage effect induced by IAA and NAA may be important from the point of view of the mechanism of toxicity of these compounds and cannot be ignored in further investigations in this area., (Copyright © 2015 Elsevier B.V. All rights reserved.)
Published: 2015
Full Text: View/download PDF

30. Grazing incidence diffraction studies of the interactions between ursane-type antimicrobial triterpenes and bacterial anionic phospholipids.

Author: Broniatowski M, Flasiński M, Wydro P, and Fontaine P
Subjects: Cardiolipins isolation & purification, Crystallization, Escherichia coli chemistry, Hydrogen Bonding, Hydrophobic and Hydrophilic Interactions, Membranes, Artificial, Oleanolic Acid chemistry, Phosphatidylglycerols isolation & purification, Thermodynamics, Ursolic Acid, Anti-Infective Agents chemistry, Cardiolipins chemistry, Oleanolic Acid analogs & derivatives, Phosphatidylglycerols chemistry, Triterpenes chemistry
Abstract: α-Amyrin (AMalf) and ursolic acid (Urs) are ursane-type pentacyclic triterpenes which exhibit wide spectrum of antibacterial activity. These surface active compounds can be incorporated into bacterial membranes and alter their structure and function; however, the exact mechanism of their action still needs to be elucidated. Thus, we decided to study the interactions of these terpenes with specific anionic phospholipids:cardiolipins and phosphatidylglycerols extracted from Escherichia coli in the model environment of Langmuir monolayers. To characterize the ordering of the terpene molecules in one-component films as well as to study their interactions with the bacterial phospholipids in binary monolayers we applied grazing incidence X-ray diffraction (GIXD). It turned out that amyrins and ursolic acid molecules form crystalline hexagonal phases in Langmuir monolayers, in which the molecules are oriented uprightly. Regarding the mixtures, it was found that in the monolayers with Urs crystalline domains are present till moderate or even low Urs proportion. In contrast, in the mixtures with AMalf crystalline domains were observed only at the highest terpene concentration. In the interpretation of our results we underlined the significance of the interactions between the cyclopropane ring present in the hydrophobic part of the bacterial phospholipids and the terminal ring of the terpene structure. We proposed that the significant differences between the systems with AMalf and Urs are connected with the formation of hydrogen bonds between the Urs hydrophobic moieties. It can be inferred from the results that Urs is a more membrane-active agent than AMalf., (Copyright © 2015 Elsevier B.V. All rights reserved.)
Published: 2015
Full Text: View/download PDF

31. Studies of the interactions of ursane-type bioactive terpenes with the model of Escherichia coli inner membrane-Langmuir monolayer approach.

Author: Broniatowski M, Mastalerz P, and Flasiński M
Subjects: Cardiolipins isolation & purification, Cell Membrane chemistry, Escherichia coli chemistry, Hydrophobic and Hydrophilic Interactions, Kinetics, Membranes, Artificial, Oleanolic Acid chemistry, Phosphatidylethanolamines isolation & purification, Phosphatidylglycerols isolation & purification, Static Electricity, Thermodynamics, Ursolic Acid, Cardiolipins chemistry, Oleanolic Acid analogs & derivatives, Phosphatidylethanolamines chemistry, Phosphatidylglycerols chemistry, Triterpenes chemistry
Abstract: Pentacyclic triterpenes (PT), ursolic acid (Urs), and α-amyrin (AMalf) are natural products exhibiting broad spectrum of antibacterial activity. These compounds are membrane-active and can disorder bacterial membranes when incorporated; however, the exact mechanism of their membrane activity is unknown. In our studies, we applied Langmuir monolayer technique supported by Brewster angle microscopy to model the interactions of the selected PT with the lipid matrix of E. coli inner membrane. As the model membrane, we applied mixtures (75/25 mole/.mole %) of the representative Escherichia coli phosphatidylethanolamine (POPE), with the cardiolipin (ECCL) or phosphatidylglycerol (ECPG) extracted from the E. coli inner membrane. On the basis of the recorded isotherms, we performed thermodynamic analysis and calculated free energy of mixing ΔGexc. It turned out that the phospholipids forming the inner membrane of E. coli are ideally miscible, whereas in binary systems composed of PT and POPE, negative deviations from ideality indicating attractive interactions between the investigated PT and POPE molecules were observed. On the other hand, in ternary systems composed of PT, POPE and one of the E. coli anionic phospholipids large positive changes in ΔGexc were observed. Thus, both PT exhibit disorganizing effect on the model E. coli membrane. It was also proved that at low terpene proportion, AMalf can be more active than Urs. However, at higher proportion Urs incorporation can lead to the disintegration of cardiolipin-rich domains present in bacterial membrane., (Copyright © 2014 Elsevier B.V. All rights reserved.)
Published: 2015
Full Text: View/download PDF

32. Incorporation of pentacyclic triterpenes into mitochondrial membrane--studies on the interactions in model 2D lipid systems.

Author: Flasiński M, Hąc-Wydro K, and Broniatowski M
Subjects: Cardiolipins chemistry, Hydrogen Bonding, Phosphatidylcholines chemistry, Phosphatidylethanolamines chemistry, Thermodynamics, Triterpenes chemistry, Betulinic Acid, Ursolic Acid, Mitochondrial Membranes chemistry, Models, Molecular, Pentacyclic Triterpenes chemistry
Abstract: Three representatives of naturally occurring pentacyclic triterpenes (PTs) were subjected to comprehensive studies aimed at the analysis of their interactions with phospholipids found naturally in mitochondrial membrane. To reach this goal, the selected compounds--α-amyrin (AMalf), betulinic acid (BAc), and ursolic acid (Urs)--were incorporated into two-component and multicomponent Langmuir monolayers acting as a model of mitochondrial membrane. As the lipids characteristic for mitochondria, phosphatidylcholine (POPC), phosphatidylethanolamine (POPE), and cardiolipin (BHCL) were chosen. Our studies were motivated by the fact that, according to the literature, the anticancer activity of PTs is correlated with their ability to incorporate into mitochondrial membrane and modify its properties. The undertaken studies were based on the surface pressure (π)-molecular area (A) isotherm registration complemented with the thermodynamic analysis and BAM visualization. It was found that all three terpenes with the exception of high betulinic acid proportion (30 and 50%) interact beneficially with POPC in two-component monolayers, while incorporation of BAc and Urs into POPE film is energetically unfavorable. As far as the model mitochondrial membrane composed of POPC/POPE/BHCL is concerned, the largest destructive influence (high positive values of ΔG(Exc) and decrease of the model monolayer condensation) was found in the case of terpene acids, while the effect of α-amyrin was energetically favorable. We postulated that the origin of the observed findings is connected with the specific interactions between bolaamphlilic terpene acids and POPE, known from its propensity to form intermolecular hydrogen bonds.
Published: 2014
Full Text: View/download PDF

33. The comparison of zymosterol vs cholesterol membrane properties--the effect of zymosterol on lipid monolayers.

Author: Hąc-Wydro K, Wydro P, and Flasiński M
Subjects: Molecular Structure, Cholesterol chemistry, Lipids chemistry, Membranes, Artificial
Abstract: In this work systematic investigations on the influence of zymosterol (zymo), which is one of cholesterol precursors, on lipid monolayers were done. The aim of these studies was to perform thorough comparison of zymosterol vs cholesterol membrane activity and fill the gap in the studies on the effect of sterols on membranes. The Langmuir monolayers experiments combined with Brewster angle microscopy studies were performed on binary (SM:zymo, POPC:zymo, GM3:zymo) and ternary (SM:POPC:zymo, SM:GM3:zymo) films differing in the sterol content. The obtained results evidenced differences in the influence of both sterols on lipid monolayers, which was manifested in the parameters calculated based on the isotherms as well is in monolayers morphology. It was found that zymosterol is of condensing, ordering and domain promoting abilities thus this molecule can be included to the group of membrane active sterols. However, zymosterol is much less effective than cholesterol as condensing and ordering agent. These findings were attributed to the differences in the structure of both sterols and their ability to pack tightly with other lipids in the mixed systems., (Copyright © 2014 Elsevier B.V. All rights reserved.)
Published: 2014
Full Text: View/download PDF

34. Interactions of pentacyclic triterpene acids with cardiolipins and related phosphatidylglycerols in model systems.

Author: Broniatowski M, Flasiński M, Zięba K, and Miśkowiec P
Subjects: Animals, Cattle, Cardiolipins chemistry, Escherichia coli chemistry, Mitochondrial Membranes chemistry, Models, Chemical, Pentacyclic Triterpenes chemistry, Phosphatidylglycerols chemistry
Abstract: Pentacyclic triterpene acids (PTAs): betulinic (BAc), oleanolic (Ola) and ursolic (Urs) are potent pharmaceuticals applied in the therapy of cancer and bacterial infections. The mechanism of PTA action is multifactor, but the important step is their interaction with the lipids of mitochondrial and bacterial membranes. In our studies we applied the Langmuir monolayer technique to investigate the interactions between PTAs and cardiolipins (CLs) and phosphatidylglycerols (PGs). We applied two different mammalian mitochondrial CLs and one species extracted from the membrane of Escherichia coli. For comparison we performed the same experiments on the systems containing PTAs and 3 PGs strictly correlated structurally to the applied CLs. Our studies proved that PTAs can disturb the organization of CL-rich domains and affect the bacterial membrane fluidity by the interactions with phosphatidylglycerols, so anionic phospholipids are the targets of their membrane action. The thermodynamic interpretation of the results indicated that Urs has the highest membrane disorganizing potential among the 3 studied PTAs. The studies performed on model systems proved also that BAc can discriminate over structurally similar animal cardiolipin species, interacts specifically with BHCL - the main mammalian CL and can disturb its organization in the membrane. In contrast, Ola and Urs are much active as far as the interaction with bacterial CLs and PGs is concerned., (Copyright © 2014 Elsevier B.V. All rights reserved.)
Published: 2014
Full Text: View/download PDF

35. Langmuir monolayer studies of the interaction of monoamphiphilic pentacyclic triterpenes with anionic mitochondrial and bacterial membrane phospholipids - searching for the most active terpene.

Author: Broniatowski M, Flasiński M, Zięba K, and Miśkowiec P
Subjects: Oleanolic Acid chemistry, Phospholipids chemistry, Bacteria chemistry, Cell Membrane chemistry, Membranes, Artificial, Mitochondrial Membranes chemistry, Oleanolic Acid analogs & derivatives, Pentacyclic Triterpenes chemistry
Abstract: The interactions of three representative monoamphiphilic pentacyclic triterpenes (PTs) with cardiolipins (CL) and phosphatidylglycerols (PG) extracted from mitochondrial and bacterial membranes were comparatively characterized in binary Langmuir monolayers. The studied terpenes: lupeol, α- and β-amyrin are isomeric compounds known from their broad biological activity. Anticancer and antimicrobial activity of PTs is often correlated with their propensity of being incorporated into mitochondrial and bacterial membranes and their specific interactions with cardiolipins. In our studies on 18 model systems surface pressure (π)-mean molecular area (A) isotherms were registered at five different component proportions in each system. Thermodynamic analysis complemented by in situ Brewster angle microscopy visualization of the investigated mixed films enabled the thorough characterization of the studied systems. It turned out that the investigated terpenes interact more favorably with PG molecules as compared to CLs. For most of the system containing CLs the values of ΔG(exc) were positive which was interpreted as the ability of the terpenes to disintegrate the membranes rich in CLs. Our results confirmed also that in the light of thermodynamic criterion α-amyrin exhibited the highest potential to disintegrate the CL containing domains in mitochondrial and bacterial membranes. The probable origin of the observed specific interactions between α-amyrin and investigated phospholipids could be explained based on the phenomenon of chiral discrimination. The obtained results were also widely discussed in reference to the biological activity of the studied compounds., (Copyright © 2014 Elsevier B.V. All rights reserved.)
Published: 2014
Full Text: View/download PDF

36. Natural vs synthetic auxin: studies on the interactions between plant hormones and biological membrane lipids.

Author: Flasiński M and Hąc-Wydro K
Subjects: Animals, Indoleacetic Acids chemical synthesis, Membrane Lipids chemical synthesis, Plant Growth Regulators chemical synthesis, Indoleacetic Acids chemistry, Membrane Lipids chemistry, Naphthaleneacetic Acids chemical synthesis, Naphthaleneacetic Acids chemistry, Plant Growth Regulators chemistry
Abstract: Analysis of the interactions between two representatives of plant hormones: synthetic (1-naphthaleneacetic acid, NAA) as well as natural (indole-3-acetic acid, IAA) and phospholipids occurring in biological membrane of both plant and animal cells was the subject of present studies. The aim of undertaken experiments was to elucidate the problem of direct influence of these plant growth regulators on phosphatidylcholines (PCs) and phosphatidylethanolamines (PEs) in monolayers at the air/water solution interface. The studied phospholipids differ not only as regards the structure of polar head-groups but also in the length of hydrophobic chains as well as their saturation degree. These differences result also in the main properties and functions of these phospholipids in biomembranes. The analysis of the results was based on the characteristics of the surface pressure (π)--area (A) isotherms registered for monolayers spread on the subphase containing plant hormone and as a reference on the surface of pure water. Moreover, as a complementary technique, Brewster angle microscopy was applied for the direct visualization of the investigated surface films. The obtained results revealed that auxins effectively influence phospholipids monolayers, regardless of the lipid structure, at the concentration of 10(-4)M. It was found that for this concentration, the influence of auxins was visibly larger in the case of PCs as compared to PEs. On the other hand, in the case of auxins solution of ≤ 10(-5)M, the observed trend was opposite. Generally, our studies showed that the natural plant hormone (IAA) interacts with the investigated lipid monolayers stronger than its synthetic derivative (NAA). The reason of these differences connects with the steric properties of both auxins; namely, the naphthalene ring of NAA molecule occupies larger space than the indole system of IAA. Therefore molecules of the latter compound penetrate easier into the region of phospholipids׳ polar head-groups. Moreover, the NH group of the indole moiety is capable of hydrogen bond formation with the acceptor groups in the polar fragment of lipid molecules. We proved also that among the investigated phospholipids, the highest susceptibility toward auxin influence show these lipids, for which during compression, surface film increases the degree of condensation., (Copyright © 2014 Elsevier Inc. All rights reserved.)
Published: 2014
Full Text: View/download PDF

37. Influence of platelet-activating factor, lyso-platelet-activating factor and edelfosine on Langmuir monolayers imitating plasma membranes of cell lines differing in susceptibility to anti-cancer treatment: the effect of plasmalogen level.

Author: Flasiński M, Hąc-Wydro K, Wydro P, and Dynarowicz-Łątka P
Subjects: Antineoplastic Agents chemistry, Cell Membrane chemistry, HL-60 Cells, Humans, K562 Cells, Membranes, Artificial, Neoplasms chemistry, Neoplasms metabolism, Phospholipid Ethers chemistry, Plasmalogens chemistry, Platelet Activating Factor chemistry, Antineoplastic Agents pharmacology, Cell Membrane metabolism, Neoplasms drug therapy, Phospholipid Ethers pharmacology, Plasmalogens metabolism, Platelet Activating Factor analogs & derivatives, Platelet Activating Factor pharmacology
Abstract: Three structurally related but differing in biological activities single-chained ether phospholipids (PAF (platelet-activating factor) and lyso-PAF) and an anti-cancer drug (edelfosine (ED)) were investigated in Langmuir monolayers imitating natural membranes. The aim of the undertaken experiments was to study the influence of these lipids on monolayers mimicking plasma membranes of cell lines differing in susceptibility to the anti-cancer activity of ED, i.e. promyelocytic leukaemia cells (HL-60) and promyeloblastic leukaemia cells (K-562). As these cells differ essentially in the cholesterol/phospholipid ratio and plasmalogen concentration in the membrane, we have carried out systematic investigations in artificial systems of various compositions. The results for model leukaemia cell membrane were compared with data acquired for systems imitating normal leucocytes. Our results show that the level of plasmalogens significantly modulates the influence of the single-chained phospholipids on the investigated systems. The experiments confirmed also that the interactions of ether lipids with a model membrane of HL-60 cells (in biological tests sensitive to ED) have opposite character when compared with K-562, being resistant to ED. Moreover, the values of the parameters characterizing monolayers serving as membrane models (strength of interactions, monolayers fluidity and morphology) proved both sensitivity of these cells to ED and lack of their susceptibility towards PAF. Interestingly, it has been found that lyso-PAF, which is usually described as an inactive precursor of PAF, displays a stronger effect on HL-60 model membranes than ED.
Published: 2014
Full Text: View/download PDF

38. Lyso-phosphatidylcholines in Langmuir monolayers--influence of chain length on physicochemical characteristics of single-chained lipids.

Author: Flasiński M, Wydro P, and Broniatowski M
Subjects: Air analysis, Hydrophobic and Hydrophilic Interactions, Kinetics, Phase Transition, Scattering, Small Angle, Structure-Activity Relationship, Surface Properties, Temperature, Thermodynamics, Water chemistry, X-Ray Diffraction, Lysophosphatidylcholines chemistry
Abstract: Single-chained phospholipids constitute a class of membrane components found in normal cells in relatively low concentration; however, these group of compounds are known owing to their broad physiological activities. Despite that the knowledge concerning fundamental physicochemical properties of lyso-lipids is very limited and in contrast to double-chained phospholipids there is an obvious deficiency of studies focused on correlation between their amphipathic character and film-forming properties with biological activities. In the present paper we have attempted to explain the main issues regarding the characteristics of lyso-PCs in monolayers at the air/aqueous interface. Our results show that all the investigated phospholipids differing in the length of hydrophobic chain: C18lyso-PC, C22lyso-PC and C24lyso-PC form stable Langmuir monolayers of a relatively low degree of condensation. It was found that during compression the investigated monolayers significantly change their organization at the interface which is strongly connected with temperature of the subphase. The application of X-ray reflectivity confirmed that the bulky choline head-groups in molecules of lyso-PCs are strongly penetrated by water molecules, while the hydrophobic chains are significantly tilted from the surface normal. The obtained results show that the phase transitions observed in the course of the registered isotherms result from decrease in immersion of molecules in the subphase as well as from the decrease in hydrating water molecules. On the basis of GIXD experiments it turned out that in the monolayers of C22lyso-PC and C24lyso-PC at higher surface pressures (>20 mN/m) small fractions of periodically ordered phase appear at the interface. For the monolayer of C24lyso-PC in the periodically ordered fraction the untilted (U) to tilted (t) phase transition was found., (Copyright © 2013 Elsevier Inc. All rights reserved.)
Published: 2014
Full Text: View/download PDF

39. Interactions between single-chained ether phospholipids and sphingomyelin in mixed monolayers at the air/water interface-Grazing incidence X-ray diffraction and Brewster angle microscopy studies.

Author: Flasiński M, Hąc-Wydro K, Wydro P, Broniatowski M, and Dynarowicz-Łątka P
Subjects: Platelet Activating Factor metabolism, Temperature, Air, Ether chemistry, Microscopy methods, Sphingomyelins chemistry, Water chemistry, X-Ray Diffraction methods
Abstract: Single-chained ether phospholipids comprise a class of both natural (PAF, lyso-PAF) and synthetic (edelfosine, ED) compounds possessing confirmed extensive biological activities. Among them ED is known to exhibit antineoplastic properties, while PAF and its lyso-precursor are lipids implicated e.g. in the functioning of organism immune system. In our study the interactions of ED, PAF and lyso-PAF with sphingomyelin (SM) being one of the main lipid found in a high concentration in membrane microdomains, like lipid rafts, were investigated in mixed monolayers at the air/water interface. The traditional Langmuir methodology was complemented with modern physicochemical techniques: Grazing incidence X-ray diffraction and Brewster angle microscopy. The investigated compounds, i.e.: platelet activating factor (PAF), (lyso-PAF) and edelfosine were selected because of their highly different physiological properties despite very similar chemical structure and evidenced membrane activity. The obtained results demonstrate that all the investigated three single-chained phospholipids cause strong modification of the model membrane properties in a concentration dependent manner. It has been proved that there are significant differences regarding the influence of the single-chained lipids on model SM membrane--in the region of low concentration, edelfosine was found to be the most effective among all the investigated compounds. The collected data shed new light onto the membrane behavior of the investigated herein biochemically active compounds, which can be of help in understanding their different biological activity and designing of new, more biocompatible drugs., (Copyright © 2013 Elsevier B.V. All rights reserved.)
Published: 2013
Full Text: View/download PDF

40. Cholesterol as a factor regulating the influence of natural (PAF and lysoPAF) vs synthetic (ED) ether lipids on model lipid membranes.

Author: Flasiński M, Wydro P, Hąc-Wydro K, and Dynarowicz-Łątka P
Subjects: Ether, Phosphatidylcholines metabolism, Cholesterol metabolism, Membrane Lipids metabolism, Membranes, Artificial, Platelet Activating Factor metabolism
Abstract: In this work we have performed a comparative study on the effect of antineoplastic ether lipid-edelfosine (ED), its natural analogs - Platelet Activating Factor (PAF) and its precursor (lyso-PAF), both lacking anticancer properties, on cholesterol/phosphatidylcholine (Chol/PC) monolayers, serving as model membranes. Since all the above ether lipids are membrane active, it can be expected that their effect on membranes may differentiate their biological activity. Our investigations were aimed at studying potential relationship of the effect of ED, PAF and lyso-PAF on model membranes, differing in condensation. We have modified molecular packing of Chol/PC model systems either by increasing the level of sterol in the system or changing the structure of PC, while keeping the same sterol content. Additionally, we have performed a detailed comparison of the miscibility of ED, PAF and lyso-PAF with various membrane lipids. The collected data evidenced that all the investigated ether lipids influence Chol/PC films in the same way; however, in a different magnitude. Moreover, the interactions of ED, PAF and lyso-PAF with model membranes were the strongest at the highest level of sterol in the system. A thorough analysis of the obtained results has proved that the effect of the investigated ether lipids on membranes is not dependent on the condensation of the system, but it is strongly determined by the concentration of cholesterol. Since ED was found to interact with model membranes stronger than PAF and lyso-PAF, we have suggested that this fact may contribute to differences in cytotoxicity of these compounds., (© 2013.)
Published: 2013
Full Text: View/download PDF

41. Miscibility and phase separation in mixed erucylphosphocholine-DPPC monolayers.

Author: Dynarowicz-Łątka P, Wnętrzak A, Broniatowski M, and Flasiński M
Subjects: Microscopy, Models, Molecular, Phosphorylcholine chemistry, Pressure, Surface Properties, Temperature, X-Ray Diffraction, 1,2-Dipalmitoylphosphatidylcholine chemistry, Phase Transition, Phosphorylcholine analogs & derivatives, Unilamellar Liposomes chemistry
Abstract: Binary Langmuir monolayers composed of 1,2-dipalmitoyl-sn-phosphatidylcholine (DPPC) and erucylphosphocholine (ErPC)--a new generation anti-cancer drug of phospholipids-like structure, have been studied with classical Langmuir technique complemented with Brewster angle microscopy (BAM) and Grazing Incidence X-ray Diffraction (GIXD). In the course of surface pressure (π)-area (A) isotherms for film containing mole fraction of ErPC (X(ErPC)) equal to 0.1, 0.2 and 0.3, two collapses appear--the value of the first one is close to the collapse pressure observed for pure ErPC, while the second one occurs at the pressure similar to that for pure DPPC. Such a behavior could imply that the investigated system is immiscible--the expulsion of a component collapsing at a lower pressure (ErPC) from mixed monolayer occurs at the first transition while DPPC (collapsing at a higher pressure value) is expelled at the final collapse. To confirm this hypothesis further analysis has been performed. Namely, thermodynamic analysis based on the calculation of the excess free enthalpy of mixing (Δ(GM)(exc)) evidenced for mutual miscibility of DPPC and ErPC in the region of surface pressures below the first collapse, which has been additionally confirmed with BAM images. On the other hand, at high surface pressures, above the first collapse (50 mN/m) GIXD experiments complemented with BAM images proved phase separation of the investigated lipids and 2D crystalline domains formation. The interpretation of the X-ray scattering results enabled us to propose a possible model of molecular packing, according to which only condensed domains of the 1:1 lipids ratio are periodically ordered; whereas at the other proportions the lipids are located randomly within the domains., (Copyright © 2013 Elsevier B.V. All rights reserved.)
Published: 2013
Full Text: View/download PDF

42. Grazing incidence X-ray diffraction and Brewster angle microscopy studies on domain formation in phosphatidylethanolamine/cholesterol monolayers imitating the inner layer of human erythrocyte membrane.

Author: Wydro P, Flasiński M, and Broniatowski M
Subjects: Cell Membrane Structures ultrastructure, Erythrocyte Membrane ultrastructure, Humans, Pressure, Surface Properties, Cell Membrane Structures chemistry, Cholesterol chemistry, Erythrocyte Membrane chemistry, Membranes, Artificial, Microscopy, Polarization, Phosphatidylethanolamines chemistry, X-Ray Diffraction
Abstract: In this work the properties of monomolecular films composed of 1-stearoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (SOPE) and cholesterol, differing in lipid proportion, were investigated in the context of domain formation in the inner leaflet of membrane. To perform comprehensive analysis of the studied model systems the Langmuir monolayer experiments were performed in combination with Brewster angle microscopy (BAM) and Grazing incidence X-ray diffraction (GIXD) techniques. The analysis of the collected data proved non-ideal behavior of the investigated films. It was found that cholesterol at its lower concentration in the system (10%) is of disturbing influence on SOPE film. Further addition of cholesterol into phospholipids film (33, 50, and 67% of cholesterol) induces an ordering effect on SOPE acyl chains and provokes the formation of sterol-poor and sterol-rich domains which stoichiometry is independent of monolayer composition. The foregoing findings allow one to conclude that in cytosolic leaflet of membrane the lipids may segregate into domains of various cholesterol contents which depending on their composition may play different roles in membrane functioning., (Copyright © 2013 Elsevier B.V. All rights reserved.)
Published: 2013
Full Text: View/download PDF

43. Does cholesterol preferentially pack in lipid domains with saturated sphingomyelin over phosphatidylcholine? A comprehensive monolayer study combined with grazing incidence X-ray diffraction and Brewster angle microscopy experiments.

Author: Wydro P, Flasiński M, and Broniatowski M
Subjects: X-Ray Diffraction, Cholesterol chemistry, Membranes, Artificial, Phosphatidylcholines chemistry, Sphingomyelins chemistry
Abstract: In this work, the Langmuir monolayers were used as a model for the analysis of the influence of cholesterol on 1,2-distearoyl-sn-glycero-3-phosphocholine - DSPC and stearoyl sphingomyelin - SSM, as well as their equimolar mixture. The aim of these studies was to compare the affinity of cholesterol to sphingomyelin and phosphatidylcholine and discuss the effectiveness of cholesterol packing with these phospholipids. The experiments involved the registration of the surface pressure-area isotherms combined with the application of Brewster angle microscopy (BAM) images and grazing incidence X-ray diffraction methods. We have performed a thorough analysis of the properties of both one-component DSPC and SSM films as well as their 1:1 mixture. Next, the effect of cholesterol on these systems was verified based on the results for 2:1 SSM/Chol, 2:1 DSPC/Chol, and 1:1:1 DSPC/SSM/Chol mixtures. It was found that both phospholipids form highly condensed monolayers, however, they differ in the orientation of acyl chains, namely the acyl chains are more tilted in DSPC film as compared to SSM monolayer as well as DSPC/SSM mixture. Furthermore, the area contraction provoked by the addition of cholesterol was found to be more pronounced for DSPC monolayer than in DSPC/SSM and SSM films. However, all the collected results allow one to postulate that the ability of cholesterol to form ordered domains with DSPC and SSM is similar and is predominantly driven by hydrophobic forces between molecules. The differences in the area condensation induced by cholesterol on the studied phospholipids films results from differences in molecular organization of pure phospholipids films rather than specific cholesterol-phospholipid interactions., (Copyright © 2013 Elsevier Inc. All rights reserved.)
Published: 2013
Full Text: View/download PDF

44. Self-organization of non-amphiphilic molecules. Studies of thin films of long-chain homologous dialkylthioethers at the water/air interface.

Author: Broniatowski M, Flasiński M, Wydro P, and Broniatowska E
Subjects: Hydrophobic and Hydrophilic Interactions, Surface Properties, X-Ray Diffraction, Air, Alkanes chemistry, Sulfides chemistry, Water chemistry
Abstract: In contrast to classical surfactants, the knowledge about the self-organization of alkanes and their hydrophobic derivatives is still limited. In this paper, we present the results of the studies of self-assembly of long-chain dialkylthioethers at the air/water interface. The substitution of one methylene group by the thioether divalent sulfur introduces significant dipole moment to the alkane chain without affecting the hydrophobicity, which profoundly influences the self-assembly of these molecules. Depending on the location of the thioether group in the hydrophobic chain, the investigated molecules can form Langmuir monolayers, which are stabilized by the thioether-water H-bonds formation, or random multilayers. The structures of the monolayers were investigated with the application of Grazing Incidence X-ray Diffraction. To elucidate important structural differences between thioether and alkane monolalyers of the same hydrocarbon chain length, we applied the methods of quantum chemistry (ETS-NOCV calculations). It turned out that the introduction of one sulfur atom affects the distribution of electron density not only in the proximity of this atom but generally along the chain. The combination of experimental and calculation methods provides to the better understanding of the fundamental question of the self-organization of long-chain alkanes and their non-amphiphilic derivatives at interfaces., (Copyright © 2013 Elsevier Inc. All rights reserved.)
Published: 2013
Full Text: View/download PDF

45. Behavior of platelet activating factor in membrane-mimicking environment. Langmuir monolayer study complemented with grazing incidence X-ray diffraction and Brewster angle microscopy.

Author: Flasiński M, Broniatowski M, Wydro P, Hąc-Wydro K, and Dynarowicz-Łątka P
Subjects: 1,2-Dipalmitoylphosphatidylcholine chemistry, Cholesterol chemistry, Microscopy, Platelet Activating Factor metabolism, Thermodynamics, X-Ray Diffraction, Membranes, Artificial, Platelet Activating Factor chemistry
Abstract: 1-O-octadecyl-2-acetyl-sn-glycero-3-phosphocholine (PAF) belonging to the class of single-chained ether phospholipids is widely known from its essential biological activities. There is a growing body of evidence that some significant aspects of PAF actions are connected with its capability to direct intercalation into biomembranes' environment. Although this mechanism is of great importance in the perspective of understanding PAF implications in various physiological processes, in the literature, there is a lack of studies devoted to this subject. It is still unknown which is the exact influence of membrane composition, molecular organization, and its other properties on the PAF impact on cells and tissues. Unfortunately, the biological studies carried out on cell cultures do not provide satisfactory results, mainly because of the complexity of natural systems. In order to obtain insight into the behavior of PAF in a lipid environment at the molecular level, the application of appropriate model systems is required. Among them, Langmuir monolayers are very often applied as a simple but very efficient platform for studies of the interactions between membrane lipids. In the present paper, special attention is focused on the issue concerning the interactions between PAF and two representatives of membrane components occurring mainly in the outer leaflet of natural bilayers, namely, cholesterol and DPPC. The application of Langmuir monolayers enabled us to construct the effective model mimicking the exogenous incorporation of PAF into membrane environment. On the basis of the obtained results, a thorough discussion was carried out and the conclusions derived from the traditional thermodynamic analysis were confronted with microscopic analysis of surface domains and the GIXD results. The selection of experimental techniques enables us to obtain information regarding the miscibility and interactions in the binary mixed films as well as the molecular organization of film-forming molecules on water surface. The experiments revealed that the addition of the investigated single-chained ether phospholipid into both cholesterol and DPPC monolayers causes a considerable decrease of monolayer condensation. On the basis of thermodynamic analysis, it was found that PAF mixes and consequently interacts strongly with cholesterol, whereas its interactions with DPPC are thermodynamically unfavorable. Differences between the PAF influence on cholesterol and DPPC monolayer found its corroboration in the results obtained with the GIXD technique. Namely, the monolayer of DPPC can incorporate more PAF than the model membrane containing cholesterol. The obtained results indicate that short chained sn-2 ether phospholipid is able to modify model membrane properties in a concentration-dependent way.
Published: 2012
Full Text: View/download PDF

46. Investigation of the interactions of lupane type pentacyclic triterpenes with outer leaflet membrane phospholipids--Langmuir monolayer and synchrotron X-ray scattering study.

Author: Broniatowski M, Flasiński M, and Wydro P
Subjects: Kinetics, Scattering, Radiation, Synchrotrons, Thermodynamics, X-Ray Diffraction, X-Rays, Betulinic Acid, 1,2-Dipalmitoylphosphatidylcholine chemistry, Pentacyclic Triterpenes chemistry, Sphingomyelins chemistry, Triterpenes chemistry
Abstract: Lupane type pentacyclic triterpenes (LTs) are pharmacologically active natural products isolated from different plants. They have broad spectrum of therapeutic action ranging from anticancer via anti-HIV, antibiotic to anti-inflammatory and anti-protozoal activity. Many scientific papers underline that the key stage in the LT mechanism of action is their incorporation into cellular membrane and the interaction with the structural lipids. In our research we apply Langmuir monolayers as a versatile platform for the investigation of these phenomena, since till now important aspects concerning this issue are incomprehensible. We focus our attention on the interactions of lupeol and betulinic acid with choline-headgroup structural lipids: a representative of saturated glycerophosphatidylcholines (DPPCs), and octadecyl-sphingomyelin--a representative of membrane sphingolipids. Application of complementary physicochemical techniques such as the Langmuir technique, Brewster angle microscopy, and grazing incidence X-ray diffraction supported by thermodynamic analysis enabled us to investigate the intermolecular interactions in such binary model systems. Our results corroborate that LT is miscible with the outer leaflet membrane phospholipids, both DPPC and SM in the whole range of mole ratios. Moreover, the introduction of LT into the phospholipid film, even in small proportion, leads to the loss of periodical ordering of the phospholipid molecules and the disappearance of the diffraction signal as observed by GIXD. Our results also proved that LT does not form any surface complexes of fixed stoichiometry resembling the well characterized lipid rafts., (Copyright © 2012 Elsevier Inc. All rights reserved.)
Published: 2012
Full Text: View/download PDF

47. Towards the understanding of the behavior of single-chained ether phospholipids in model biomembranes: interactions with phosphatidylethanolamines in Langmuir monolayers.

Author: Hąc-Wydro K, Flasiński M, Wydro P, and Dynarowicz-Łątka P
Subjects: Membranes, Artificial, Phosphatidylethanolamines chemistry, Phospholipid Ethers chemistry
Abstract: Three single-chained ether lipids of comparable chemical structure but different biological activities (namely natural platelet activating factor - PAF, its deacetylated precursor - lyso-PAF and synthetic compound - edelfosine - ED) have been investigated in mixed Langmuir monolayers with phosphatidylethanolamines, PEs (DSPE, SOPE and DOPE), serving as model of inner shell of cellular membrane. The aim of undertaken studies was to verify the correlation between minor differences in chemical structures of the investigated ether lipids and their behavior in membrane-mimicking environment. To reach this goal the interactions between particular ether lipids and PEs have been analyzed with ΔG(Exc) values derived from the surface pressure-area isotherms. To get insight into miscibility between film components, Brewster angle microscopy, enabling direct visualization of monolayers structure, has been applied. The obtained results prove significant differences in both mixing properties and the interactions in the investigated systems. On one hand, they are related to the structure of polar head-groups of the studied ether lipids, which determine their capability of hydrogen bond(s) formation with head-groups of PEs. Edelfosine, lacking this property, interacts with PEs the most unfavorably among all the investigated compounds. Another important parameter in this context is the structure of PEs monolayers - the most closely packed DSPE film was found to be most unfavorable for incorporation of ether lipid molecules. Our results prove that the analysis of the interaction between ether lipids and components of biomembrane in Langmuir monolayers is a potent method to explain differences in biological activity of the investigated ether lipids., (Copyright © 2012 Elsevier B.V. All rights reserved.)
Published: 2012
Full Text: View/download PDF

48. Molecular organization of bacterial membrane lipids in mixed systems--A comprehensive monolayer study combined with Grazing Incidence X-ray Diffraction and Brewster Angle Microscopy experiments.

Author: Wydro P, Flasiński M, and Broniatowski M
Subjects: Bacteria chemistry, Membranes, Artificial, Microscopy methods, X-Ray Diffraction methods, Lipid Bilayers chemistry, Membrane Lipids chemistry, Phosphatidylethanolamines chemistry, Phosphatidylglycerols chemistry
Abstract: To properly design and investigate new antibacterial drugs a detailed description of the organization of bacterial membrane is highly important. Therefore in this work we performed a comprehensive characteristic of the Langmuir monolayers composed of phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) mixed in a wide range of composition and treated as an artificial cytoplasmic layer of bacterial membrane. To obtain detailed information on the properties of these films we combined the analysis of the surface pressure-area curves with the surface potential measurements, Brewster Angle Microscopy studies and Grazing Incidence X-ray Diffraction experiments. It was found that the investigated phospholipids mix nonideally in the monolayers and that the most favorable packing of molecules occurs at their equimolar proportion. This is directly connected with the formation of hydrogen bonds between both types of molecules in the system. All the collected experimental data evidenced that dipalmitoylphosphatidylethanolamine (DPPE) and dipalmitoylphosphatidylglycerol (DPPG) form highly ordered associates of fixed (DPPE:DPPG 1:1) stoichiometry. The obtained results allow one to conclude a nonuniform distribution of lipids in bacterial membranes and the existence of domains composed of the investigated phospholipids. The latter seems to be of great importance in the perspective of further studies on the mechanism of action of antibacterial agents.
Published: 2012
Full Text: View/download PDF

49. Lupane-type pentacyclic triterpenes in Langmuir monolayers: a synchrotron radiation scattering study.

Author: Broniatowski M, Flasiński M, and Wydro P
Subjects: Scattering, Radiation, X-Ray Diffraction, Surface Properties, Triterpenes chemistry
Abstract: Lupane-type pentacyclic triterpenes (lupeol, betulin, and betulinic acid) are natural products isolated from various plant sources. The terpenes exhibit a vast spectrum of biological activity and are applied in therapies for different diseases, among which the anticancer, anti-HIV, antihypercholesteremic, and antiinflammatory are the most promising. These chemicals possess amphiphilic structure and were proved to interact strongly with biomembranes, which can be the key stage in their mechanism of action. In our studies, we applied Langmuir monolayers as versatile models of biomembranes. It turned out that the three investigated terpenes are capable of stable monolayer formation; however, these monolayers differ profoundly regarding their physicochemical characteristics. In our research, we applied the Langmuir technique (surface pressure-mean molecular area (π-A) isotherm registration) coupled with Brewster angle microscopy (BAM), but the main focus was on the synchrotron radiation scattering method, grazing incidence X-ray diffraction (GIXD), which provides information on the amphiphilic molecule ordering in the angström scale. It was proved that all the investigated terpenes form crystalline phases in their monolayers. In the case of lupeol, only the closely packed upright phase was observed, whereas for betulin and betulinic acid, the phase situation was more complex. Betulinic acid molecules can be organized in an upright phase, which is crystalline, and in a tilted phase, which is amorphous. The betulin film is a conglomerate of an upright crystalline monolayer phase, tilted amorphous monolayer phase, and a crystalline tilted bilayer. In our paper, we discuss the factors leading to the formation of the observed phases and the implications of our results to the therapeutic applications of the native lupane-type triterpenes.
Published: 2012
Full Text: View/download PDF

50. Comparative characteristics of membrane-active single-chained ether phospholipids: PAF and lyso-PAF in Langmuir monolayers.

Author: Flasiński M, Broniatowski M, Wydro P, and Dynarowicz-Łątka P
Subjects: Air, Hydrogen Bonding, Water chemistry, Lysophosphatidylcholines chemistry, Phospholipid Ethers chemistry
Abstract: 1-O-Octadecyl-2-acetyl-sn-glycero-3-phosphocholine (PAF) and its deacetylated precursor (lyso-PAF) are membrane-active single-chained ether phospholipids, which play an important signaling role in different physiological processes. There is strong evidence that one of the possible mechanisms of PAF and lyso-PAF activity is connected with their direct influence on biomembranes. Although both lipids have very similar structure, their biological activity is very different and in some cases even antagonistic. Unfortunately, there is a lack of the studies correlating these observations with the molecular structure of both compounds. Therefore, we decided to apply model systems and advanced physicochemical methods to explore this subject and look for the reasons of the observed discrepancies. As a model system, we prepared Langmuir monolayers of PAF and lyso-PAF at the air/water interface. The physicochemical characteristic of the model membranes under different experimental conditions was performed with the application of the Langmuir monolayer technique, Brewster angle microscopy, and the methods based on synchrotron radiation scattering (XR and GIXD). Both compounds form stable Langmuir monolayers, in which the lipid molecules are strongly immersed into the water subphase. The monolayers have expanded character, meaning that the hydrophobic tails are considerably tilted and disordered. Similarly to biochemical studies, also in our model systems, profound differences in the properties of PAF and lyso-PAF were observed. Contrary to PAF, the lyso-PAF molecules express the propensity to form organized, periodical structures in the model membranes. It is manifested in the phase transition observed in the course of the lyso-PAF π-A isotherm which was correlated with the diffraction signal registered with the application of the GIXD method. The formation of 2D domains of hexagonal ordering of the film forming molecules was observed only for the lyso precursor. The observed differences between PAF and lyso-PAF were explained taking into consideration the chemical activity of the free hydroxyl group present in the headgroup of the latter molecule. The formation of hydrogen bonds between the lyso-PAF molecules as well as the stronger hydration of its hydrophilic fragment can be the key factor differentiating the activity of PAF and lyso-PAF in the investigated systems as well as in the native biomembranes., (© 2012 American Chemical Society)
Published: 2012
Full Text: View/download PDF

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Language

Publication Type

Journal

Database

Publisher

57 results on '"M. Flasiński"'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources