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1. Large scale test of wedge shaped micro strip gas counters

Author

J.-M. Brom, C. Vander Velde, V. Nagaslaev, T. Beckers, Piero Giorgio Verdini, R. Metri, G. Smadja, V. Zhukov, D. Pandoulas, W. Van Doninck, F. Udo, Oliver Pooth, B. Schwaller, J. Croix, S. Barthe, S. Bachmann, G. Schuster, P. Schmitz, Amina Zghiche, Bruno Wittmer, C. Hoffman, Hans-Jürgen Simonis, Rasmus Ischebeck, C. Camps, S. Weseler, J.M Helleboid, Pascal Vanlaer, K. Lübelsmeyer, H. Szczesny, K. Bernier, V. Chorowicz, K. Hangarter, W.H. Thümmel, S. Tissot, M. Hoffer, Th. Müller, A. Schultz von Dratzig, V. Commichau, E. Ruoff, Abdenour Lounis, T. Todorov, A. Bondar, C. Racca, J. P. Coffin, Fabien Jeanneau, W. Geist, W. Beaumont, I. Boulogne, Günter Flügge, Laurent Mirabito, Reinhard W. Schulte, S. Atz, R. Siedling, M. Bozzo, M. R. Kapp, Y. Benhammou, D. Neuberger, M. Krauth, C. Maazouzi, A. Sauer, Jean-Charles Fontaine, A. Pallares, D. Huss, V. Titov, D. Knoblauch, M. Tonutti, J. Kremp, J.P. Schunk, K. Kärcher, M. Petertill, Th. Henkes, F. Beißel, Pierre Juillot, Othmane Bouhali, J. Stefanescu, Ch.Van Dyck, D. Macke, H. Eberlé, P. Blüm, L. Shektman, R. Wortmann, Ulrich Goerlach, Didier Contardo, F. Drouhin, S. Junghans, M. Ackermann, M. Kräber, V. Aulchenko, K. Gundlfinger, Andreas Nowack, J. De Troy, A. M. Bergdolt, L. Van Lancker, M.-H. Sigward, Aysen Tatarinov, I. Ripp, B. Baiboussinov, and R. Haroutunian

Subjects
Physics, Nuclear and High Energy Physics, Large Hadron Collider, Muon, Physics::Instrumentation and Detectors, business.industry, Detector, Wedge (geometry), Gaseous particle detectors, Particle detector, Chemistry, Optics, Measuring instrument, High Energy Physics::Experiment, business, Engineering sciences. Technology, Instrumentation, Image resolution, Beam (structure)
Abstract

In order to check the system aspects of the forward-backward MSGC tracker designed for the future CMS experiment at LHC: 38 trapezoidal MSGC counters assembled in six multi-substrates detector modules were built and exposed to a muon beam at the CERN SPS. Results on the gain uniformity along the wedge-shaped strip pattern and across the detector modules are shown together with measurements of the detection efficiency and the spatial resolution. (C) 1999 Elsevier Science B.V. All rights reserved.

Published
1999
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2. Observation of a Coherence Length Effect in Exclusiveρ0Electroproduction

Author

K. Ackerstaff, A. Airapetian, N. Akopov, I. Akushevich, M. Amarian, E. C. Aschenauer, H. Avakian, R. Avakian, A. Avetissian, B. Bains, S. Barrow, C. Baumgarten, M. Beckmann, St. Belostotski, J. E. Belz, Th. Benisch, S. Bernreuther, N. Bianchi, S. Blanchard, J. Blouw, H. Böttcher, A. Borissov, J. Brack, S. Brauksiepe, B. Braun, B. Bray, St. Brons, W. Brückner, A. Brüll, E. E. W. Bruins, H. J. Bulten, R. V. Cadman, G. P. Capitani, P. Carter, P. Chumney, E. Cisbani, G. R. Court, P. F. Dalpiaz, P. P. J. Delheij, E. De Sanctis, D. De Schepper, E. Devitsin, P. K. A. de Witt Huberts, P. Di Nezza, M. Düren, A. Dvoredsky, G. Elbakian, J. Ely, J. Emerson, A. Fantoni, A. Fechtchenko, M. Ferstl, D. Fick, K. Fiedler, B. W. Filippone, H. Fischer, H. T. Fortune, B. Fox, S. Frabetti, J. Franz, S. Frullani, M.-A. Funk, N. D. Gagunashvili, P. Galumian, H. Gao, Y. Gärber, F. Garibaldi, G. Gavrilov, P. Geiger, V. Gharibyan, V. Giordjian, A. Golendukhin, G. Graw, O. Grebeniouk, P. W. Green, L. G. Greeniaus, C. Grosshauser, M. G. Guidal, A. Gute, V. Gyurjyan, J. P. Haas, W. Haeberli, J.-O. Hansen, D. Hasch, O. Häusser, F. H. Heinsius, R. S. Henderson, Th. Henkes, M. Henoch, R. Hertenberger, Y. Holler, R. J. Holt, W. Hoprich, H. Ihssen, M. Iodice, A. Izotov, H. E. Jackson, A. Jgoun, C. Jones, R. Kaiser, E. Kinney, M. Kirsch, A. Kisselev, P. Kitching, H. Kobayashi, N. Koch, K. Königsmann, M. Kolstein, H. Kolster, V. Korotkov, W. Korsch, V. Kozlov, L. H. Kramer, B. Krause, V. G. Krivokhijine, M. Kückes, F. Kümmell, G. Kyle, W. Lachnit, W. Lorenzon, A. Lung, N. C. R. Makins, F. K. Martens, J. W. Martin, F. Masoli, A. Mateos, M. McAndrew, K. McIlhany, R. D. McKeown, F. Meissner, F. Menden, D. Mercer, A. Metz, N. Meyners, O. Mikloukho, C. A. Miller, M. A. Miller, R. G. Milner, V. Mitsyn, A. Most, R. Mozzetti, V. Muccifora, A. Nagaitsev, Y. Naryshkin, A. M. Nathan, F. Neunreither, M. Niczyporuk, W.-D. Nowak, M. Nupieri, P. Oelwein, H. Ogami, T. G. O'Neill, R. Openshaw, J. Ouyang, B. R. Owen, V. Papavassiliou, S. F. Pate, M. Pitt, H. R. Poolman, S. Potashov, D. H. Potterveld, B. Povh, G. Rakness, A. Reali, R. Redwine, A. R. Reolon, R. Ristinen, K. Rith, H. Roloff, G. Röper, P. Rossi, S. Rudnitsky, M. Ruh, D. Ryckbosch, Y. Sakemi, I. Savin, C. Scarlett, F. Schmidt, H. Schmitt, G. Schnell, K. P. Schüler, A. Schwind, J. Seibert, T.-A. Shibata, T. Shin, V. Shutov, C. Simani, A. Simon, K. Sinram, P. Slavich, J. Sowinski, M. Spengos, E. Steffens, J. Stenger, J. Stewart, F. Stock, U. Stoesslein, M. Sutter, H. Tallini, S. Taroian, A. Terkulov, D. M. Thiessen, E. Thomas, B. Tipton, A. Trudel, M. Tytgat, G. M. Urciuoli, J. J. van Hunen, R. van de Vyver, J. F. J. van den Brand, G. van der Steenhoven, M. C. Vetterli, V. Vikhrov, M. Vincter, J. Visser, E. Volk, W. Wander, T. P. Welch, S. E. Williamson, T. Wise, T. Wölfel, K. Woller, S. Yoneyama, K. Zapfe-Düren, H. Zohrabian, and R. Zurmühle

Subjects
Physics, HERMES experiment, Particle physics, Meson, 010308 nuclear & particles physics, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Nuclear Theory, General Physics and Astronomy, Virtual particle, 01 natural sciences, Coherence length, Positron energy, Nuclear physics, Deuterium, Nuclear transparency, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Exclusive incoherent electroproduction of the ρ0(770) meson from 1H, 2H, 3He, and 14N targets has been studied by the HERMES experiment at squared four-momentum transfer Q^2>0.4 GeV^2 and positron energy loss ν from 9 to 20 GeV. The ratio of the 14N to 1H cross sections per nucleon, known as the nuclear transparency, was found to decrease with increasing coherence length of quark-antiquark fluctuations of the virtual photon. The data provide clear evidence of the interaction of the quark-antiquark fluctuations with the nuclear medium.

Published
1999
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3. Beam-induced nuclear depolarization in a gaseous polarized-hydrogen target

Author

Yasuhiro Sakemi, Valeri Valentinovitch Mitsyn, R. P. Redwine, G. van der Steenhoven, J. van Hunen, L. G. Greeniaus, A. Gute, L. H. Kramer, E. Volk, P. Chumney, S. Frullani, H. Schmitt, F. Stock, Ross Milner, T. A. Shibata, E. De Sanctis, R.O. Avakian, A. Metz, N. Koch, J. Franz, H. Kolster, M.-A. Funk, J.-O. Hansen, A.O. Mateos, A. Borissov, B. D. Fox, E. Devitsin, E. Cisbani, S. Potashov, H. Zohrabian, A. R. Reolon, A. Avetissian, K. McIlhany, I.A. Savin, K. Sinram, R. J. Holt, A. Izotov, T. Wise, F. Masoli, F. Neunreither, J. Blouw, S. Bernreuther, Alan M. Nathan, G.R. Court, F. Schmidt, R. V. Cadman, V. A. Korotkov, N.D. Gagunashvili, Y. Gärber, M. Beckmann, M. McAndrew, G. S. Kyle, H. J. Bulten, Michael Pitt, J. F. J. van den Brand, Th. Henkes, J. Stewart, V. Gharibyan, W. Haeberli, S. Frabetti, A. Brull, Brons, M. Ferstl, M. Sutter, M. Amarian, K. Ackerstaff, Klaus Rith, Robert Henderson, E. R. Kinney, Wolfgang Korsch, A. Reali, E. E. W. Bruins, H. Avakian, A. Airapetian, W. Wander, A. Dvoredsky, A. Nagaitsev, E. C. Aschenauer, H. E. Jackson, V. G. Krivokhijine, K. Königsmann, O. Häusser, G. P. Capitani, Y. Naryshkin, H. Ihssen, Michel Vetterli, M. Kolstein, Haiyan Gao, O. Grebeniouk, Ralf Hertenberger, M. Ruh, A. Schwind, A. Simon, F. K. Martens, M. Nupieri, G. Elbakian, W. Brückner, C. Baumgarten, M. Spengos, P. Di Nezza, S. Brauksiepe, N. Akopov, Michael Tytgat, V. Giordjian, A. Golendukhin, S. I. Manaenkov, M. A. Miller, G. Rakness, M. Henoch, P. Geiger, P. Slavich, V. A. Kozlov, S. Taroian, F. Meissner, P. Rossi, W. Lachnit, D. De Schepper, C. Grosshauser, R. A. Ristinen, Y. Holler, Alessandra Fantoni, N. Meyners, B. R. Owen, H.O. Roloff, P. F. Dalpiaz, G. Graw, D. Hasch, D. H. Potterveld, K. Zapfe-Düren, H. Böttcher, S. F. Pate, Jeffrey Brack, B. W. Filippone, F. Garibaldi, J. Stenger, D. Fick, J. E. Belz, R. D. McKeown, P.K.A. de Witt Huberts, M. Niczyporuk, A. Jgoun, Mauro Iodice, V. Papavassiliou, Belostotski, S. Yoneyama, R. Van de Vyver, G. M. Urciuoli, W.-D. Nowak, H. Ogami, T. Shin, Manuella Vincter, A. Kisselev, H. Tallini, Wolfgang Lorenzon, W. Hoprich, U. Stoesslein, H. Fischer, J. W. Martin, S. Rudnitsky, Dirk Ryckbosch, J. Sowinski, B. Tipton, Hiroaki Kobayashi, K. Fiedler, K. Woller, Thomas O'Neill, P.W. Green, B. Braun, K. P. Schüler, Nicola Bianchi, O. Mikloukho, V. Shutov, B. Bains, C. Simani, Naomi C R Makins, R. Mozzetti, Ralf Kaiser, E. Steffens, G. Gavrilov, A. Fechtchenko, B. Bray, P. Kitching, Th. Benisch, M. Düren, P. Carter, C. A. Miller, Adel Terkulov, Valeria Muccifora, G. Schnell, S. E. Williamson, and (Astro)-Particles Physics

Subjects
HERMES experiment, Physics, Hydrogen, General Physics and Astronomy, chemistry.chemical_element, FOS: Physical sciences, DESY, Depolarization, HERA, Magnetic field, High Energy Physics - Experiment, NO, High Energy Physics - Experiment (hep-ex), Bunches, chemistry, Physics::Accelerator Physics, High Energy Physics::Experiment, Atomic physics, Beam (structure)
Abstract

Spin-polarised atomic hydrogen is used as a gaseous polarised proton target in high energy and nuclear physics experiments operating with internal beams in storage rings. When such beams are intense and bunched, this type of target can be depolarised by a resonant interaction with the transient magnetic field generated by the beam bunches. This effect has been studied with the HERA positron beam in the HERMES experiment at DESY. Resonances have been observed and a simple analytic model has been used to explain their shape and position. Operating conditions for the experiment have been found where there is no significant target depolarisation due to this effect., REVTEX, 6 pages, 5 figures

Published
1999
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4. Design and performance of a large microstrip gas tracker for HERMES

Author

J. Blouw, M. Kolstein, J. Visser, J. F. J. van den Brand, E Kok, M. Kraan, J. van Hunen, F Udo, H. J. Bulten, M. Doets, Th. Henkes, F.G Hartjes, and (Astro)-Particles Physics

Subjects
Physics, HERMES experiment, Nuclear and High Energy Physics, business.industry, Physics::Instrumentation and Detectors, Detector, STRIPS, HERA, COUNTERS, Microstrip, law.invention, Anode, Optics, law, High Energy Physics::Experiment, Vertex detector, SDG 7 - Affordable and Clean Energy, business, Instrumentation
Abstract

A vertex detector consisting of twelve microstrip gas counters with a total of 24 800 anode strips was constructed for the HERMES experiment at HERA. The active area of the detector equals 137 x 406 mm(2). It is equipped with a digital readout system. Here, we report on the design of the tracker and the performance during the 1995 running period at the HERMES experiment. (C) 1999 Elsevier Science B.V. All rights reserved.

Published
1999
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5. The HERMES spectrometer

Author

K. Ackerstaff, A. Airapetian, N. Akopov, M. Amarian, V. Andreev, E.C. Aschenauer, R. Avakian, H. Avakian, A. Avetissian, B. Bains, S. Barrow, W. Beckhusen, M. Beckmann, St. Belostotski, E. Belz, Th. Benisch, S. Bernreuther, N. Bianchi, J. Blouw, H. Böttcher, A. Borissov, J. Brack, B. Braun, B. Bray, S. Brons, W. Brückner, A. Brüll, H.J. Bulten, G.P. Capitani, P. Carter, P. Chumney, E. Cisbani, S. Clark, S. Colilli, H. Coombes, G.R. Court, P. Delheij, E. Devitsin, C.W. de Jager, E. De Sanctis, D. De Schepper, P.K.A. de Witt Huberts, P. Di Nezza, M. Doets, M. Düren, A. Dvoredsky, G. Elbakian, J. Emerson, A. Fantoni, A. Fechtchenko, M. Ferstl, D. Fick, K. Fiedler, B.W. Filippone, H. Fischer, H.T. Fortune, J. Franz, S. Frullani, M.-A. Funk, N.D. Gagunashvili, P. Galumian, H. Gao, Y. Gärber, F. Garibaldi, G. Gavrilov, P. Geiger, V. Gharibyan, V. Giordjian, F. Giuliani, A. Golendoukhin, B. Grabowski, G. Graw, O. Grebeniouk, P. Green, G. Greeniaus, M. Gricia, C. Grosshauser, A. Gute, J.P. Haas, K. Hakelberg, W. Haeberli, J.-O. Hansen, D. Hasch, O. Hausser, R. Henderson, Th. Henkes, R. Hertenberger, Y. Holler, R.J. Holt, H. Ihssen, A. Izotov, M. Iodice, H.E. Jackson, A. Jgoun, C. Jones, R. Kaiser, J. Kelsey, E. Kinney, M. Kirsch, A. Kisselev, P. Kitching, H. Kobayashi, E. Kok, K. Königsmann, M. Kolstein, H. Kolster, W. Korsch, S. Kozlov, V. Kozlov, R. Kowalczyk, L. Kramer, B. Krause, A. Krivchitch, V.G. Krivokhijine, M. Kueckes, P. Kutt, G. Kyle, W. Lachnit, R. Langstaff, W. Lorenzon, M. Lucentini, A. Lung, N. Makins, V. Maleev, S.I. Manaenkov, K. Martens, A. Mateos, K. McIlhany, R.D. McKeown, F. Meißner, F. Menden, D. Mercer, A. Metz, N. Meyners, O. Mikloukho, C.A. Miller, M.A. Miller, R. Milner, V. Mitsyn, G. Modrak, J. Morton, A. Most, R. Mozzetti, V. Muccifora, A. Nagaitsev, Y. Naryshkin, A.M. Nathan, F. Neunreither, M. Niczyporuk, W.-D. Nowak, M. Nupieri, P. Oelwein, H. Ogami, T.G. O’Neill, R. Openshaw, V. Papavassiliou, S.F. Pate, S. Patrichev, M. Pitt, H.J. Plett, H.R. Poolman, S. Potashov, D. Potterveld, B. Povh, V. Prahl, G. Rakness, V. Razmyslovich, R. Redwine, A.R. Reolon, R. Ristinen, K. Rith, H.O. Roloff, G. Röper, P. Rossi, S. Rudnitsky, H. Russo, D. Ryckbosch, Y. Sakemi, F. Santavenere, I. Savin, F. Schmidt, H. Schmitt, G. Schnell, K.P. Schüler, A. Schwind, T.-A. Shibata, T. Shin, B. Siebels, A. Simon, K. Sinram, W.R. Smythe, J. Sowinski, M. Spengos, K. Sperber, E. Steffens, J. Stenger, J. Stewart, F. Stock, U. Stößlein, M. Sutter, H. Tallini, S. Taroian, A. Terkulov, D. Thiessen, B. Tipton, V. Trofimov, A. Trudel, M. Tytgat, G.M. Urciuoli, R. Van de Vyver, J.F.J. van den Brand, G. van der Steenhoven, J.J. van Hunen, D. van Westrum, A. Vassiliev, M.C. Vetterli, M.G. Vincter, E. Volk, W. Wander, T.P. Welch, S.E. Williamson, T. Wise, G. Wöbke, K. Woller, S. Yoneyama, K. Zapfe-Düren, T. Zeuli, H. Zohrabian, and (Astro)-Particles Physics

Subjects
HERMES experiment, Nuclear and High Energy Physics, Particle physics, semi-inclusive scattering, (e, Physics::Instrumentation and Detectors, Cherenkov detector, CALORIMETERS, FOS: Physical sciences, deep inelastic lepton scattering, (e,e''h), Tracking (particle physics), Particle identification, High Energy Physics - Experiment, INORGANIC MATERIALS, law.invention, High Energy Physics - Experiment (hep-ex), e''h), GAS-MIXTURES, law, Nuclear Experiment, Instrumentation, Physics, Calorimeter (particle physics), Spectrometer, PERFORMANCE, magnetic spectrometer, Deep inelastic scattering, Transition radiation detector, CHAMBERS, High Energy Physics::Experiment
Abstract

The HERMES experiment is collecting data on inclusive and semi-inclusive deep inelastic scattering of polarised positrons from polarised targets of H, D, and He. These data give information on the spin structure of the nucleon. This paper describes the forward angle spectrometer built for this purpose. The spectrometer includes numerous tracking chambers (micro-strip gas chambers, drift and proportional chambers) in front of and behind a 1.3 T.m magnetic field, as well as an extensive set of detectors for particle identification (a lead-glass calorimeter, a pre-shower detector, a transition radiation detector, and a threshold Cherenkov detector). Two of the main features of the spectrometer are its good acceptance and identification of both positrons and hadrons, in particular pions. These characteristics, together with the purity of the targets, are allowing HERMES to make unique contributions to the understanding of how the spins of the quarks contribute to the spin of the nucleon., 37 pages, 32 figures, 4 tables

Published
1998
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6. Measurement of the neutron spin structure function g with a polarized 3He internal target

Author

K. Ackerstaff, A. Airapetian, I. Akushevich, N. Akopov, M. Amarian, E.C. Aschenauer, R. Avakian, H. Avakian, A. Avetissian, B. Bains, S. Barrow, M. Beckmann, S. Belostotski, J.E. Belz, Th. Benisch, S. Bernreuther, N. Bianchi, S. Blanchard, J. Blouw, H. Böttcher, A. Borissov, J. Brack, B. Braun, B. Bray, W. Brückner, A. Brüll, E.E.W. Bruins, H.J. Bulten, G.P. Capitani, P. Carter, E. Cisbani, G.R. Court, P.P.J. Delheij, E. Devitsin, C.W. de Jager, E. De Sanctis, D. De Schepper, P.K.A. de Witt Huberts, M. Düren, A. Dvoredsky, G. Elbakian, J. Emerson, A. Fantoni, A. Fechtchenko, M. Ferstl, D. Fick, K. Fiedler, B.W. Filippone, H. Fischer, H.T. Fortune, J. Franz, S. Frullani, M.-A. Funk, N.D. Gagunashvili, P. Galumian, H. Gao, Y. Gärber, F. Garibaldi, P. Geiger, V. Gharibyan, A. Golendoukhin, G. Graw, O. Grebeniouk, P.W. Green, L.G. Greeniaus, C. Grosshauser, A. Gute, V. Gyurjyan, J.P. Haas, W. Haeberli, J.-O. Hansen, D. Hasch, O. Häusser, R.S. Henderson, Th. Henkes, R. Hertenberger, Y. Holler, R.J. Holt, H. Ihssen, M. Iodice, A. Izotov, H.E. Jackson, A. Jgoun, C. Jones, R. Kaiser, E. Kinney, M. Kirsch, A. Kisselev, P. Kitching, N. Koch, K. Königsmann, M. Kolstein, H. Kolster, W. Korsch, V. Kozlov, L.H. Kramer, B. Krause, V.G. Krivokhijine, M. Kückes, G. Kyle, W. Lachnit, W. Lorenzon, A. Lung, N.C.R. Makins, S.I. Manaenkov, F.K. Martens, J.W. Martin, A. Mateos, K. McIlhany, R.D. McKeown, F. Meissner, D. Mercer, A. Metz, N. Meyners, O. Mikloukho, C.A. Miller, M.A. Miller, R.G. Milner, V. Mitsyn, A. Most, R. Mozzetti, V. Muccifora, A. Nagaitsev, Y. Naryshkin, A.M. Nathan, F. Neunreither, M. Niczyporuk, W.-D. Nowak, M. Nupieri, P. Oelwein, H. Ogami, T.G. O'Neill, R. Openshaw, V. Papavassiliou, S.F. Pate, M. Pitt, S. Potashov, D.H. Potterveld, B. Povh, G. Rakness, R. Redwine, A.R. Reolon, R. Ristinen, K. Rith, G. Röper, H. Roloff, P. Rossi, S. Rudnitsky, M. Ruh, D. Ryckbosch, Y. Sakemi, I. Savin, K.P. Schüller, A. Schwind, T.-A. Shibata, T. Shin, A. Simon, K. Sinram, W.R. Smythe, J. Sowinski, M. Spengos, E. Steffens, J. Stenger, J. Stewart, F. Stock, U. Stoesslein, M. Sutter, H. Tallini, S. Taroian, A. Terkulov, D.M. Thiessen, B. Tipton, A. Trudel, M. Tytgat, G.M. Urciuoli, R. Van de Vyver, J.F.J. van den Brand, G. van der Steenhoven, M.C. Vetterli, E. Volk, W. Wander, T.P. Welch, S.E. Williamson, T. Wise, T. Wölfel, K. Zapfe-Düren, H. Zohrabian, and R. Zurmühle

Subjects
Physics, HERMES experiment, Nuclear and High Energy Physics, Range (particle radiation), 010308 nuclear & particles physics, Astrophysics::Cosmology and Extragalactic Astrophysics, HERA, Spin structure, Deep inelastic scattering, 01 natural sciences, Nuclear physics, Positron, 0103 physical sciences, High Energy Physics::Experiment, Neutron, Atomic physics, 010306 general physics, Spin-½
Abstract

Results are reported from the HERMES experiment at HERA on a measurement of the neutron spin structure function g1n(x, Q2) in deep inelastic scattering using 27.5 GeV longitudinally polarized positrons incident on a polarized 3He internal gas target. The data cover the kinematic range 0.023

Published
1997
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7. Performance of F101 radiation resistant lead glass shower counters

Author

M. Nupieri, V. Giourdjian, R. Avakian, A. R. Reolon, A. Avetissian, B. W. Filippone, M. Amarian, G. P. Capitani, M. Kolstein, A. Airapetian, N. Akopov, M. Doets, Alessandra Fantoni, P. Galumian, Valeria Muccifora, S. Taroian, A. Simon, Th. Henkes, V. Garibian, E. De Sanctis, P. Rossi, Nicola Bianchi, J. F. J. van den Brand, R. Mozzetti, B. Bray, H. Avakian, A. Lung, and (Astro)-Particles Physics

Subjects
Physics, Nuclear and High Energy Physics, Range (particle radiation), Radiation resistant, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Resolution (electron density), Linearity, Nuclear physics, Lead glass, Optics, DESIGN, ELECTROMAGNETIC CALORIMETER, visual_art, visual_art.visual_art_medium, SPECTROMETER, High Energy Physics::Experiment, business, Instrumentation, Cherenkov radiation
Abstract

The performance of F101 lead glass as a Cherenkov radiation material was studied. A 3 x 3 array of 9 x 9 cm(2) and 50 cm length counters showed an energy resolution of approximate to 5.0%/root E(GeV), good linearity in the energy range from 1 to 25 GeV and pi(-)/e rejection of approximate to 4 x 10(-4).

Published
1996
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8. The Flavor Asymmetry of the Light Quark Sea from Semi-inclusive Deep-inelastic Scattering

Author

K. Ackerstaff, A. Airapetian, N. Akopov, I. Akushevich, M. Amarian, E. C. Ashenauer, H. Avakian, R. Avakian, A. Avetissian, B. Bains, C. Baumgarten, M. Beckmann, St. Belostotski, J. E. Belz, Th. Benisch, S. Bernreuther, N. Bianchi, J. Blouw, H. Böttcher, A. Borissov, J. Brack, S. Brauksiepe, B. Braun, B. Bray, St. Brons, W. Brückner, A. Brüll, E. E. W. Bruins, H. J. Bulten, R. V. Cadman, G. P. Capitani, P. Carter, P. Chumney, E. Cisbani, G. R. Court, P. F. Dalpiaz, E. De Sanctis, D. De Schepper, E. Devitsin, P. K. A. de Witt Huberts, P. Di Nezza, M. Düren, A. Dvoredsky, G. Elbakian, A. Fantoni, A. Fechtchenko, M. Ferstl, K. Fiedler, B. W. Filippone, H. Fischer, B. Fox, J. Franz, S. Frullani, M.-A. Funk, N. D. Gagunashvili, H. Gao, Y. Gärber, F. Garibaldi, G. Gavrilov, P. Geiger, V. Gharibyan, V. Giordjian, A. Golendukhin, G. Graw, O. Grebeniouk, P. W. Green, L. G. Greeniaus, C. Grosshauser, A. Gute, W. Haeberli, J.-O. Hansen, D. Hasch, O. Häusser, R. Henderson, Th. Henkes, M. Henoch, R. Hertenberger, Y. Holler, R. J. Holt, W. Hoprich, H. Ihssen, M. Iodice, A. Izotov, H. E. Jackson, A. Jgoun, R. Kaiser, E. Kinney, A. Kisselev, P. Kitching, H. Kobayashi, N. Koch, K. Königsmann, M. Kolstein, H. Kolster, V. Korotkov, W. Korsch, V. Kozlov, L. H. Kramer, V. G. Krivokhijine, M. Kurisuno, G. Kyle, W. Lachnit, W. Lorenzon, N. C. R. Makins, S. I. Manaenkov, F. K. Martens, J. W. Martin, F. Masoli, A. Mateos, M. McAndrew, K. McIlhany, R. D. McKeown, F. M. Menden, F. Meissner, A. Metz, N. Meyners, O. Mikloukho, C. A. Miller, M. A. Miller, R. Milner, V. Mitsyn, A. Most, R. Mozzetti, V. Muccifora, A. Nagaitsev, Y. Naryshkin, A. M. Nathan, F. Neunreither, M. Niczyporuk, W.-D. Nowak, M. Nupieri, T. G. O'Neill, J. Ouyang, B. R. Owen, V. Papavassiliou, S. F. Pate, M. Pitt, S. Potashov, D. H. Potterveld, G. Rakness, A. Reali, R. Redwine, A. R. Reolon, R. Ristinen, K. Rith, H. Roloff, P. Rossi, S. Rudnitsky, M. Ruh, D. Ryckbosch, Y. Sakemi, I. Savin, F. Schmidt, H. Schmitt, G. Schnell, K. P. Schüler, A. Schwind, T.-A. Shibata, K. Shibatani, T. Shin, V. Shutov, C. Simani, A. Simon, K. Sinram, P. Slavich, M. Spengos, E. Steffens, J. Stenger, J. Stewart, U. Stoesslein, M. Sutter, H. Tallini, S. Taroian, A. Terkulov, B. Tipton, M. Tytgat, G. M. Urciuoli, J. J. van Hunen, R. van de Vyver, J. F. J. van den Brand, G. van der Steenhoven, M. C. Vetterli, M. G. Vincter, E. Volk, W. Wander, S. E. Williamson, T. Wise, K. Woller, S. Yoneyama, H. Zohrabian, and (Astro)-Particles Physics

Subjects
Quark, Particle physics, Proton, media_common.quotation_subject, High Energy Physics::Lattice, Nuclear Theory, General Physics and Astronomy, FOS: Physical sciences, PROTON, 01 natural sciences, 7. Clean energy, Asymmetry, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Pion, DRELL-YAN PROCESS, 0103 physical sciences, 010306 general physics, NUCLEON, Nuclear Experiment, media_common, Physics, 010308 nuclear & particles physics, Scattering, High Energy Physics::Phenomenology, Deep inelastic scattering, Deuterium, PARTON DISTRIBUTIONS, High Energy Physics::Experiment, Nucleon, BREAKING
Abstract

The flavor asymmetry of the light quark sea of the nucleon is determined in the kinematic range 0.02, Comment: 7 Pages, 2 figures, RevTeX format; slight revision in text, small change in extraction of dbar-ubar and comparison with a high q2 parameterization

Published
1998
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9. New data on semihadronic decays of the τ lepton

Author

M. J. Schachter, J. Bouchez, O. Hamon, A. Cordier, G. Schmidt, R. George, Y. Lavagne, F. Laplanche, B. Forstbauer, W. D. Apel, F. Pierre, G. Grindhammer, Eduardo Ros, B. Grossetete, Jean-Francois Grivaz, P. Grosse-Wiesmann, J. Haissinski, H. Schneider, C. Kiesling, H. Fenner, U. Kruse, H. J. Behrend, M. Goldberg, Y. Ducros, U. Mallik, G. Hopp, F. Kovacs, H. Müller, Patrick Jarry, G. Cozzika, Peter Schacht, H. Küster, O. Achterberg, J. Pamela, J. J. Veillet, G. D'Agostini, G. Bonneaud, R. Aleksan, K. Gamerdinger, Th. Henkes, R. Kotthaus, P. Colas, H. Sindt, J. H. Field, Werner Wiedenmann, A. Gaidot, W. Fues, Horst Oberlack, V. Journé, G. Flügge, D. Lüers, V. Schröder, J. P. Pansart, J. Engler, M. Rivoal, M. Krüger, F. Kapusta, B. Gunderson, F. Le Diberder, G. Buschhorn, Daniel Fournier, R. Pain, Luc Poggioli, H. Lierl, G. Carnesecchi, G. London, D. C. Fries, H. Randoll, W. De Boer, and M. Davier

Subjects
Physics, Particle physics, Physics and Astronomy (miscellaneous), High Energy Physics::Lattice, Electron–positron annihilation, Nuclear Theory, Current algebra, Elementary particle, Nuclear physics, Particle acceleration, Pion, High Energy Physics::Experiment, Quantum field theory, Nuclear Experiment, Engineering (miscellaneous), Charged current, Lepton
Abstract

Branching ratios for the decay τ→ν+(n pions) withn≧2 are presented. The new data include all possible charge configurations of the pion system and, in particular, final states containing one or several neutral pions. The data are compared with predictions from CVC (even number of pions in final state) and current algebra (odd number of pions). They strongly support the standard coupling of the τ to the weak charged current.

Published
1984
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10. Observation of a multiparticle event with two isolated energetic muons in e+e- interactions

Author

R. George, Jean-Arcady Meyer, F. Kovacs, G. Hopp, M. Gaspero, Peter Schacht, H. Küster, G. D'Agostini, L. Criegee, K. Gamerdinger, Patrick Jarry, G. Schmidt, B. Gunderson, Alan Campbell, W. De Boer, G. Grindhammer, Kevin M. Smith, G. Carnesecchi, Jean-Francois Grivaz, Th. Henkes, O. Hamon, A. Cordier, Daniel Fournier, W. Fues, V. Journé, Gideon Alexander, Gideon Bella, H. Schneider, C. Kiesling, H. Fenner, M. Goldberg, G. G. Winter, H. Randoll, M. Davier, W. Zimmermann, F. Pierre, G. Bonneaud, J. Haissinski, Luc Poggioli, R. Pain, J. J. Veillet, R. Aleksan, Eduardo Ros, G. Flügge, J. Knapp, D. Lüers, I. O. Skillicorn, J. M. Scarr, V. Schröder, P. J. Bussey, F. Kapusta, U. Timm, H. J. Behrend, J. H. Field, P. Grosse-Wiesmann, F. Le Diberder, G. Buschhorn, Y. Gnat, D. C. Fries, G. Franke, A. Gaidot, D. Hendry, Horst Oberlack, Y. Lavagne, G. Cozzika, F. Ould Saada, B. Stella, R. Kotthaus, H. Lierl, H. Sindt, H. Spitzer, K. H. Ranitzsch, O. Achterberg, P. Colas, Y. Ducros, U. Mallik, H. Müller, J. B. Dainton, J. P. Pansart, J. Engler, J. Pamela, M. Krüger, M. Rivoal, J. Bürger, J. Grunhaus, J. Bouchez, B. Forstbauer, W. D. Apel, M. Poppe, Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and CELLO

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Muon, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Electron–positron annihilation, Hadron, Expected value, 01 natural sciences, Nuclear physics, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, 010306 general physics, Event (particle physics)
Abstract

An event from e+e− annihilation at √s = 43.450 GeV containing two topologically isolated energetic muons and two hadronic jets has been observed. The masses of the μ−μ, jet-jet and μ-jet combinations are all large. The expected number of such events from known processes is about 10−3.

Published
1984
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11. Production of thef 0(1270) meson in photon-photon collisions

Author

Eduardo Ros, R. George, F. Kapusta, Werner Wiedenmann, R. Kotthaus, Peter Schacht, Y. Lavagne, H. J. Behrend, W. Fues, H. Randoll, V. Journé, M. Davier, B. Grossetete, G. D'Agostini, Daniel Fournier, G. London, F. Laplanche, K. Gamerdinger, J. H. Field, D. C. Fries, G. Grindhammer, F. Le Diberder, G. Carnesecchi, A. Cordier, B. Forstbauer, H. Lierl, CELLO-Collaboration, W. D. Apel, Luc Poggioli, R. Pain, O. Hamon, Th. Henkes, F. Pierre, B. Gunderson, A. Snyder, G. Hopp, U. Kruse, P. Grosse-Wiesmann, Jean-Francois Grivaz, Patrick Jarry, W. De Boer, M. Rivoal, G. Cozzika, G. Flügge, C. Kiesling, D. Lüers, H. Fenner, M. Krüger, H. Schneider, V. Schröder, J. Bouchez, G. Buschhorn, J. Pamela, M. J. Schachter, F. Kovacs, G. Schmidt, J. J. Veillet, R. Aleksan, M. Goldberg, A. Gaidot, Horst Oberlack, J. Haissinski, H. Sindt, G. Bonneaud, O. Achterberg, P. Colas, J. P. Pansart, J. Engler, Y. Ducros, U. Mallik, and H. Müller

Subjects
Physics, Nuclear physics, Particle physics, Photon, Amplitude, Physics and Astronomy (miscellaneous), Meson, Radiative transfer, Mass spectrum, Elementary particle, Engineering (miscellaneous), Helicity, Free parameter
Abstract

The production of thef0 in two photon collisions, with the subsequent decayf0→π+π− has been observed in the CELLO detector at PETRA. Thef0 peak was found to lie on a dipion continuum and to be shifted downwards in mass by ≃50 MeV/c2. The ππ mass spectrum from 0.8 to 1.5 GeV/c2 was well fitted by the model of Mennessier using only a unitarised Born amplitude and helicity 2f0 amplitude. The previously observed mass shift and distortion of thef0 peak are explained by strong interference between the Born andf0 amplitudes. The only free parameter in the fit of the data to the model is the radiative widthΓγγ(f0). It was found that:Γγγ(f0)=2.5±0.1±0.5 keV where the first (second) quoted errors are statistical (systematic).

Published
1984
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12. Excited Lepton search

Author

F. Kovacs, J. J. Veillet, R. Aleksan, J. D. Burger, G. Grindhammer, D. Hendry, Y. Gnat, B. Gunderson, H. Spitzer, K. H. Ranitzsch, M. Goldberg, B. Sack, Volker Blobel, I. O. Skillicorn, J. Grunhaus, O. Hamon, J. Knapp, Horst Oberlack, Y. Holler, Alan Campbell, M. Gaspero, M. Davier, Y. Lavagne, Luc Poggioli, J. M. Scarr, G. G. Winter, Kevin M. Smith, Y. Ducros, Ch. Kiesling, Peter Bussey, G. Hopp, Peter Schacht, H. Küster, G. D'Agostini, Patrick Jarry, Gideon Bella, M. Krüger, A. Spadafora, F. Pierre, G. Cozzika, L. Criegee, J. Hansmeyer, U. Timm, K. Gamerdinger, J. H. Field, H. Müller, G. McCurrach, G. Buschhorn, F. Ould Saada, Werner Wiedenmann, Patrick Janot, B. Stella, Hannes Jung, G. Franke, A. Cordier, D. C. Fries, R. Kotthaus, Th. Henkes, B. Fatah, J. Engler, P. Grosse-Wiesmann, Gideon Alexander, H. Schneider, H. Sindt, Eduardo Ros, Juan Fuster, J. Zacek, G. Shooshtari, H. J. Behrend, J. Haissinski, J. B. Dainton, W. Fues, M. Rivoal, G. Flügge, D. Lüers, V. Journé, V. Schröder, R. George, W. D. Apel, M. Poppe, F. Le Diberder, Jean-Arcady Meyer, Hubert Kroha, W. Christiansen, M. Gaillard, Jean-Francois Grivaz, H. Fenner, J. Pamela, F. Kapusta, W. De Boer, Daniel Fournier, W. Zimmermann, and R. Pain

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Electron–positron annihilation, Excited state, Yield (chemistry), High Energy Physics::Experiment, Lepton
Abstract

Using the CELLO detector at PETRA a search has been made for excited leptons by studying e + e − interactions which yield l + l − γγ, l + l − γ and γγ final states, where l =e,μ or τ . Good agreement with QED is observed and new limits are set on e ∗ , μ ∗ , and τ ∗ production.

Published
1986
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13. Measurement of the reaction γγ→π+π+π−π− at PETRA

Author

M. Krüger, Y. Ducros, M. Rivoal, U. Mallik, H. Müller, Luc Poggioli, Peter Schacht, P. Grosse-Wiesmann, H. Küster, O. Achterberg, A. Cordier, G. Grindhammer, M. J. Schachter, G. D'Agostini, P. Colas, Daniel Fournier, K. Gamerdinger, Y. Lavagne, Eduardo Ros, R. Kotthaus, F. Kovacs, O. Hamon, F. Pierre, B. Forstbauer, W. D. Apel, B. Grossetete, H. J. Behrend, J. J. Veillet, R. Aleksan, G. Cozzika, R. Pain, F. Laplanche, H. Lierl, G. Schmidt, A. Gaidot, B. Gunderson, Horst Oberlack, J. H. Field, W. Fues, V. Journé, W. De Boer, G. Carnesecchi, M. Goldberg, Jean-Francois Grivaz, C. Kiesling, J. Haissinski, J. Bouchez, H. Fenner, H. Sindt, G. Buschhorn, G. Flügge, D. Lüers, Th. Henkes, F. Kapusta, V. Schröder, J. Pamela, G. Hopp, F. Le Diberder, Patrick Jarry, J. P. Pansart, J. Engler, G. London, D. C. Fries, H. Schneider, G. Bonneaud, H. Randoll, M. Davier, R. George, and U. Kruse

Subjects
Nuclear physics, Physics, Cross section (physics), Physics and Astronomy (miscellaneous), Moment analysis, Phase space, Resonance, Engineering (miscellaneous), Helicity, Uncorrelated
Abstract

We have determined the cross section for γγ→π+π+π−π− in a way free of assumptions about the relative contributions fromρ 0 ρ 0,ρ 02π and 4π (uncorrelated phase space). We find a sharp onset above threshold and a rather high cross section of about 200 nb aroundW γγ=1.5 GeV which consists to about 40% ofρ 0 ρ 0 production with sizeable contributions fromρ 02π and 4π (PS). The total cross section as well as theρ 0 ρ 0 content fall rather fast at higher c.m. energies. Attempts to explain this behaviour in terms of production of known resonances are not successful so far. The angular distributions do not show any significant structure pointing to resonance formation in the 4π-system. Only theρ 0-meson is observed in the moment analysis. The decay distributions of theρ 0 for forward produced rhos are fairly consistent with helicity conservation of the produced rhos in accordance with the VDM picture.

Published
1984
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14. An investigation of the processes e+e−→μ+μ−γ and e+e−→e+e−γ

Author

M. Krüger, P. Grosse-Wiesmann, J. Haissinski, U. Timm, F. Ould Saada, B. Stella, W. De Boer, G. Flügge, D. Lüers, Th. Henkes, W. Zimmermann, W. D. Apel, J. M. Scarr, M. Poppe, Hubert Kroha, V. Schröder, G. Grindhammer, A. Cordier, Luc Poggioli, M. Davier, H. Sindt, R. Kotthaus, D. Hendry, Y. Ducros, G. Buschhorn, B. Scharlemann, M. Rivoal, H. Müller, Eduardo Ros, Volker Blobel, Werner Wiedenmann, R. George, W. Fues, G. Franke, Y. Lavagne, Jean-Francois Grivaz, J. Knapp, A. Spadafora, B. Gunderson, H. Fenner, V. Journé, H. Spitzer, Ch. Kiesling, K. H. Ranitzsch, J. Pamela, Jean-Arcady Meyer, H. J. Behrend, M. Gaillard, Y. Gnat, Alan Campbell, J. Grunhaus, J. B. Dainton, M. Gaspero, G. Cozzika, G. G. Winter, Horst Oberlack, G. Hopp, M. Goldberg, Patrick Jarry, F. Le Diberder, Gideon Alexander, Hannes Jung, H. Schneider, J. D. Burger, W. Christiansen, B. Fatah, Peter Schacht, J. H. Field, H. Küster, J. Hansmeyer, G. Shooshtari, Daniel Fournier, F. Kapusta, R. Pain, K. Gamerdinger, P. J. Bussey, D. C. Fries, G. D'Agostini, F. Kovacs, J. J. Veillet, R. Aleksan, J. Engler, Kevin M. Smith, L. Criegee, O. Hamon, Gideon Bella, F. Pierre, G. McCurrach, and I. O. Skillicorn

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, High energy, Dalitz plot, High Energy Physics::Experiment, Nuclear Experiment, Storage ring
Abstract

The reactions e + e − → μ + μ − γ and e + e − →e + e − γ have been studied with the CELLO detector at the PETRA storage ring. Data have been collected from s =14 GeV up to 46.8 GeV . In a Dalitz plot analysis of the data, good agreement is found with QED, except for the region Mx μγ e>0.8 where the probability that QED describes the high energy data is at the percent level.

Published
1985
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15. A search for single photons at PETRA

Author

Alan Campbell, Gideon Bella, F. Pierre, G. G. Winter, G. McCurrach, Luc Poggioli, Kevin M. Smith, O. Hamon, Daniel Fournier, Y. Holler, Y. Ducros, B. Gunderson, Th. Henkes, B. Fatah, Peter Bussey, D. Hendry, B. Sack, L. Criegee, A. Cordier, M. Gaspero, H. Müller, Y. Lavagne, F. Kovacs, G. Franke, G. D'Agostini, Craig Buttar, F. Ould Saada, B. Stella, R. George, J. J. Veillet, R. Aleksan, Eduardo Ros, H. Spitzer, G. Flügge, D. Lüers, F. Ferrarotto, Jean-Arcady Meyer, G. Shooshtari, G. Hopp, K. H. Ranitzsch, G. Grindhammer, F. Le Diberder, J. D. Burger, V. Schröder, J. Zacek, J. Engler, H. J. Behrend, P. Grosse-Wiesmann, Gideon Alexander, M. Davier, W. De Boer, H. Schneider, H. Sindt, J. H. Field, M. Feindt, J. Haissinski, A. Spadafora, Peter Schacht, H. Küster, W. Fues, J. B. Dainton, G. Cozzika, I. O. Skillicorn, K. Gamerdinger, Ch. Kiesling, J. M. Scarr, Hannes Jung, Aharon Levy, J. Hansmeyer, Volker Blobel, V. Journé, J. Knapp, W. Zimmermann, D. C. Fries, R. Kotthaus, M. Goldberg, Y. Gnat, G. Buschhorn, Horst Oberlack, F. Kapusta, W. Christiansen, M. Krüger, Juan Fuster, J. Pamela, P. Mayer, M. Rivoal, J. Grunhaus, M. Gaillard, J. Wolf, Werner Wiedenmann, W. D. Apel, M. Poppe, Jean-Francois Grivaz, H. Fenner, A. Böhrer, U. Timm, Hubert Kroha, Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), CELLO, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Photon, 010308 nuclear & particles physics, Scalar (mathematics), Degenerate energy levels, Electron, 01 natural sciences, Massless particle, Nuclear physics, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Particle, High Energy Physics::Experiment, Neutrino, 010306 general physics, Storage ring
Abstract

A search for single photons, produced in e + e − collisions together with particles interacting only weakly with matter, has been performed using the CELLO detector operating at the PETRA storage ring. From the absence of any signal, an upper limit is set at 15 (90% CL) on the number of light neutrino species, and lower limits on various supersymmetric particle masses are derived. For massless photinos, mass degenerate scalar partners of the left- and right-handed electrons are excluded below 37.7 GeV/ c 2 (90% CL).

Published
1986

16. On the model dependence of the determination of the strong coupling constant in second order QCD from $e^+e^-$ annihilation into hadrons

Author

M. Krüger, Luc Poggioli, A. Cordier, Eduardo Ros, O. Achterberg, Y. Lavagne, G. Flügge, D. Lüers, Daniel Fournier, V. Schröder, B. Grossetete, F. Le Diberder, R. George, O. Hamon, Peter Schacht, H. Küster, G. Hopp, H. Lierl, F. Pierre, G. Grindhammer, R. Pain, G. D'Agostini, M. Rivoal, G. Cozzika, G. Bonneaud, J. Bouchez, A. Gaidot, K. Gamerdinger, G. Buschhorn, Jean-Francois Grivaz, M. J. Schachter, P. Colas, G. Carnesecchi, Horst Oberlack, R. Kotthaus, B. Gunderson, H. J. Behrend, Patrick Jarry, C. Kiesling, W. Fues, H. Fenner, V. Journé, W. De Boer, F. Kovacs, Y. Ducros, H. Schneider, G. London, U. Mallik, D. C. Fries, J. J. Veillet, F. Laplanche, J. H. Field, J. P. Pansart, J. Engler, H. Müller, R. Aleksan, P. Grosse-Wiesmann, Th. Henkes, G. Schmidt, H. Randoll, M. Davier, F. Kapusta, M. Goldberg, J. Haissinski, U. Kruse, H. Sindt, B. Forstbauer, W. D. Apel, J. Pamela, Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and CELLO

Subjects
Physics, Quantum chromodynamics, Nuclear and High Energy Physics, Particle physics, Annihilation, Chiral perturbation theory, 010308 nuclear & particles physics, High Energy Physics::Lattice, Electron–positron annihilation, Nuclear Theory, High Energy Physics::Phenomenology, Hadron, Detector, 01 natural sciences, Hadronization, Nuclear physics, 0103 physical sciences, Quark–gluon plasma, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics
Abstract

Hadronic events obtained with the CELLO detector at PETRA are compared with second order QCD predictions using different models for the fragmentation of quarks and gluons into hadrons. We find that the model dependence in the determination of the strong coupling constant persists when going from first to second order QCD calculations.

Published
1984

17. Experimental limit on monojet production in e+e--annihilation

Author

F. Ould Saada, B. Stella, F. Kapusta, F. Kovacs, M. Gaspero, Kevin M. Smith, H. Sindt, J. J. Veillet, R. George, R. Aleksan, Daniel Fournier, J. Hansmeyer, Peter Schacht, B. Sack, O. Hamon, R. Kotthaus, Jean-Arcady Meyer, L. Criegee, G. Grindhammer, M. Goldberg, K. Gamerdinger, G. D'Agostini, Alan Campbell, I. O. Skillicorn, G. Buschhorn, Juan Fuster, Werner Wiedenmann, G. G. Winter, Gideon Bella, Peter Bussey, H. Spitzer, J. M. Scarr, K. H. Ranitzsch, J. Engler, Volker Blobel, F. Pierre, A. Spadafora, P. Grosse-Wiesmann, G. Shooshtari, M. Rivoal, J. H. Field, J. Knapp, G. McCurrach, F. Le Diberder, J. Haissinski, Luc Poggioli, M. Gaillard, Y. Gnat, M. Davier, G. Cozzika, W. De Boer, R. Pain, B. Gunderson, D. C. Fries, Gideon Alexander, D. Hendry, J. Grunhaus, H. Schneider, Hannes Jung, W. Zimmermann, Y. Lavagne, Horst Oberlack, J. B. Dainton, J. Pamela, V. Journé, Eduardo Ros, M. Krüger, A. Cordier, H. J. Behrend, Y. Ducros, Th. Henkes, W. Christiansen, H. Müller, G. Franke, J. Zacek, W. Fues, J. D. Burger, W. D. Apel, M. Poppe, Jean-Francois Grivaz, H. Fenner, Ch. Kiesling, G. Hopp, Patrick Jarry, B. Fatah, U. Timm, Hubert Kroha, Y. Holler, G. Flügge, D. Lüers, and V. Schröder

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Electron–positron annihilation, High Energy Physics::Phenomenology, Higgs boson, High Energy Physics::Experiment, Production (computer science), Limit (mathematics), Boson
Abstract

We have searched for monojet production in e + e − -annihilation with the CELLO detector operating at the highest PETRA energies. No events were found, which makes it unlikely that the recently observed monojets in p p collisions originate from unusual Z 0 decays. The upper limits on monojet cross sections are compared with various models, thus yielding upper limits on the production cross sections of Higgs bosons and higgsinos.

18. Limits on spin 0 bosons in e+e- annihilation up to 45.2 GeV CM energy

Author

B. Gunderson, O. Hamon, Gideon Bella, Daniel Fournier, Alan Campbell, Luc Poggioli, F. Pierre, Jean-Francois Grivaz, R. Pain, J. D. Burger, F. Kapusta, G. Buschhorn, D. Hendry, G. Hopp, Eduardo Ros, G. G. Winter, I. O. Skillicorn, W. D. Apel, Y. Lavagne, M. Poppe, B. Forstrauer, J. Grunhaus, Patrick Jarry, G. Bonneaud, H. J. Behrend, G. Cozzika, J. Knapp, G. Grindhammer, G. Carnesecchi, G. Schmidt, J. Pamela, R. Kotthaus, G. Flügge, D. Lüers, H. Lierl, Peter Schacht, H. Küster, W. Fues, J. M. Scarr, P. J. Bussey, V. Schröder, H. Spitzer, G. D'Agostini, R. George, M. Goldberg, V. Journé, Th. Henkes, K. Gamerdinger, F. Lediberder, K. H. Ranitzsch, J. P. Pansart, J. Engler, W. De Boer, Jean-Arcady Meyer, H. Randoll, D. C. Fries, M. Davier, M. Rivoal, J. Bouchez, W. Zimmermann, M. Gaspero, M. Krüger, J. Haissinski, Gideon Alexander, H. Schneider, A. Cordier, C. Kiesling, H. Fenner, U. Timm, J. H. Field, F. Kovacs, J. J. Veillet, R. Aleksan, F. Ould Saada, B. Stella, H. Sindt, Y. Gnat, A. Gaidot, Horst Oberlack, P. Grosse-Wiesmann, Y. Ducros, U. Mallik, H. Müller, G. Franke, Kevin M. Smith, L. Criegee, J. B. Dainton, O. Achterberg, and P. Colas

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Range (particle radiation), Annihilation, Radiative transfer, High Energy Physics::Experiment, Spin (physics), Energy (signal processing), Boson
Abstract

We have studied the reactions e + e − → e + e − , e + e − → γγ , e + e − → μ + μ − , and e + e − → τ + τ − in the centre-of-mass (CM) energy range from 39.8 to 45.2 GeV using the CELLO detector at PETRA. Upper limits on the partial widths for new spin 0 bosons with masses both within and above the energy range covered are determined. No evidence for contributions of such new particles has been observed up to the highest PETRA energies in a model independent way. Under the assumptions of recently suggested models relating the existence of spin 0 bosons to the radiative width Γ τ of the Z 0 we exclude such bosons at the 95% confidence level for masses below the Z 0 -mass if Γ τ > 20 MeV.

19. Search for new heavy quarks in e+e- collisions up to 46.78 GeV CM energy

Author

M. Krüger, G. Grindhammer, G. Buschhorn, Daniel Fournier, J. P. Pansart, J. Engler, J. Pamela, G. Franke, Alan Campbell, J. Bouchez, Kevin M. Smith, F. Kovacs, J. J. Veillet, R. Aleksan, O. Hamon, G. Hopp, Gideon Bella, H. Lierl, R. Pain, U. Timm, Patrick Jarry, J. H. Field, J. Grunhaus, G. Schmidt, F. Pierre, L. Criegee, J. B. Dainton, O. Achterberg, Y. Gnat, B. Gunderson, R. George, W. De Boer, Jean-Francois Grivaz, M. Rivoal, D. C. Fries, C. Kiesling, Jean-Arcady Meyer, H. Fenner, P. Grosse-Wiesmann, W. Zimmermann, A. Gaidot, P. Colas, M. Gaspero, I. O. Skillicorn, M. Goldberg, Horst Oberlack, F. Ould Saada, B. Stella, J. Büger, Y. Ducros, R. Rotthaus, U. Mallik, H. Müller, Th. Henkes, P. J. Bussey, W. Fues, H. J. Behrend, G. Carnesecchi, H. Sindt, J. Haissinski, V. Journé, H. Spitzer, G. G. Winter, K. H. Ranitzsch, J. M. Scarr, Luc Poggioli, G. Bonneaud, D. Hendry, G. Flügge, D. Lüers, Y. Lavagne, V. Schröder, H. Randoll, M. Davier, Gideon Alexander, H. Schneider, A. Cordier, Peter Schacht, H. Küster, G. D'Agostini, K. Gamerdinger, J. Knapp, G. Cozzika, Eduardo Ros, F. Kapusta, F. Le Diberder, B. Forstbauer, W. D. Apel, and M. Poppe

Subjects
Systematic error, Physics, Quark, Nuclear and High Energy Physics, Particle physics, Annihilation, Branching fraction, Electron–positron annihilation, Hadron, Flavour, Nuclear physics, High Energy Physics::Experiment, Nuclear Experiment, Ground state
Abstract

The total e+e− annihilation onto hadron has been measured at CM energies between 33.00 and 36.72 GeV and between 38.66 and 46.78 GeV in steps of 20 and 30 MeV respectively. The average of the ratio R=σ(e+e−→hadrons)/ σ is 〈R〉=3.85±0.12 and 〈R〉=4.04±0.10 for the two energy ranges. The systematic error on 〈R〉 is 0.31. Both values are consistent with the expectation for the known coloured quarks u, d, s, c and b. No evidence was found for the production of new quarks. If the largest fluctuation in R is interpreted as a narrow resonance, it corresponds to a product of the electronic width and the hadronic branching ratio ΓeeBhad>2.9 keV at the 95% confidence level, well below the value expected for the toponium vector ground state with charge 2 3 e . The observed number of aplanar final states rules out the continuum production of a a new heavy flavour with pointlike cross section up to a CM energy of 45.4 GeV for a quarck charge of 1 3 e . and up to 46.6 GeV for 2 3 e at the 95% confidence level.

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