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35 results on '"D. POTTERVELD"'

2. Measurement of R=σL/σT and the separated longitudinal and transverse structure functions in the nucleon-resonance region

Author

Y. Liang, V. Tvaskis, M. E. Christy, A. Ahmidouch, C. S. Armstrong, J. Arrington, R. Asaturyan, S. Avery, O. K. Baker, D. H. Beck, H. P. Blok, C. W. Bochna, W. Boeglin, P. Bosted, M. Bouwhuis, H. Breuer, D. S. Brown, A. Bruell, R. D. Carlini, J. Cha, N. S. Chant, A. Cochran, L. Cole, S. Danagoulian, D. B. Day, J. Dunne, D. Dutta, R. Ent, H. C. Fenker, B. Fox, L. Gan, H. Gao, K. Garrow, D. Gaskell, A. Gasparian, D. F. Geesaman, R. Gilman, P. L. J. Guèye, M. Harvey, R. J. Holt, X. Jiang, M. Jones, C. E. Keppel, E. Kinney, W. Lorenzon, A. Lung, D. J. Mack, P. Markowitz, J. W. Martin, K. McIlhany, D. McKee, D. Meekins, M. A. Miller, R. G. Milner, J. H. Mitchell, H. Mkrtchyan, B. A. Mueller, A. Nathan, G. Niculescu, I. Niculescu, T. G. O'Neill, V. Papavassiliou, S. F. Pate, R. B. Piercey, D. Potterveld, R. D. Ransome, J. Reinhold, E. Rollinde, O. Rondon, P. Roos, A. J. Sarty, R. Sawafta, E. C. Schulte, E. Segbefia, C. Smith, S. Stepanyan, S. Strauch, V. Tadevosyan, L. Tang, R. Tieulent, A. Uzzle, W. F. Vulcan, S. A. Wood, F. Xiong, L. Yuan, M. Zeier, B. Zihlmann, and V. Ziskin

Published
2022

3. Fission Barrier of Superheavy Nuclei and Persistence of Shell Effects at High Spin: Cases of 254No and 220Th

Author

Greg, Henning, T L, Khoo, A, Lopez-Martens, D, Seweryniak, M, Alcorta, M, Asai, B B, Back, P F, Bertone, D, Boilley, M P, Carpenter, C J, Chiara, P, Chowdhury, B, Gall, P T, Greenlees, G, Gürdal, K, Hauschild, A, Heinz, C R, Hoffman, R V F, Janssens, A V, Karpov, B P, Kay, F G, Kondev, S, Lakshmi, T, Lauritsen, C J, Lister, E A, McCutchan, C, Nair, J, Piot, D, Potterveld, P, Reiter, A M, Rogers, N, Rowley, S, Zhu, CSNSM SNO, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), 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)-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)-Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), 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), Université de Caen Normandie (UNICAEN), Normandie Université (NU), Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), 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), 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)-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)-Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
superheavy elements, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], fysiikka, ComputingMilieux_MISCELLANEOUS, 27.90.+b, 21.10.Hw, 24.60.Dr, 24.75.+i
Abstract

We report on the first measurement of the fission barrier height in a heavy shell-stabilized nucleus. The fission barrier height of 254No is measured to be Bf=6.0±0.5 MeV at spin 15ℏ and, by extrapolation, Bf=6.6±0.9 MeV at spin 0ℏ. This information is deduced from the measured distribution of entry points in the excitation energy versus spin plane. The same measurement is performed for 220Th and only a lower limit of the fission barrier height can be determined: Bf(I)8 MeV. Comparisons with theoretical fission barriers test theories that predict properties of superheavy elements.

Published
2014

4. Electroproduction of kaons on light nuclei

Author

R. Sawafta, J. H. Liu, John C. Mitchell, T. Eden, C. Yan, D. G. Meekins, E. Christy, F. Dohrmann, P. Ambrozewicz, L. Cole, M. Sarsour, A. Ahmidouch, Y. Sato, P. E. Reimer, S. Tajima, J. A. Dunne, J. Roche, S. Danagoulian, Kevin Bailey, B. Mueller, J. W. Price, W. Hinton, N. S. Chant, H. Mkrtchyan, J. Crowder, H. Juengst, Haiyan Gao, John Arrington, G. Savage, C. Cothran, J. P. Schiffer, B. Zihlmann, M. Zeier, H. C. Fenker, J.-O. Hansen, Paul Gueye, Rolf Ent, R. D. Carlini, Brian Raue, R. Asaturyan, L. Gan, W. J. Cummings, A. Semenov, D. F. Geesaman, J. Cha, D. S. Brown, M. Elaasar, A. Cochran, H. Breuer, Dipangkar Dutta, Pete Markowitz, L. Yuan, J. Reinhold, H. Bitao, A. Uzzle, K. Gustafsson, B. Terburg, F. Duncan, S. Stepanyan, P. G. Roos, Ketevi Assamagan, Avraham Klein, G. Collins, Thomas O'Neill, D. Potterveld, V. Tadevosian, K. Garrow, H. E. Jackson, D. Koltenuk, C. S. Armstrong, Y. Liang, O. K. Baker, I. Niculescu, B. Zeidman, A. F. Lung, G. Niculescu, Toshinobu Miyoshi, H. Yamaguchi, R. Madey, D. Abbott, L. Ewell, H. T. Fortune, Y. Fujii, K. Hafidi, R. E. Segel, S. Beedoe, S. Mtingwa, C. J. Martoff, R. Mohring, C. E. Keppel, S. A. Wood, D. J. Mack, Stephen Avery, and L. G. Tang

Subjects
Physics, Nuclear and High Energy Physics, Meson, Proton, Helium-3, Hadron, Production (computer science), Elementary particle, Atomic physics, Nuclear Experiment, Lambda, Isotopes of helium
Abstract

The A(e,e{prime}K{sup +})YX reaction on H, D, {sup 3}He, and {sup 4}He was investigated in Hall C at CEBAF. Data were obtained for Q{sup 2} {approx} 0.35 and 0.5 GeV{sup 2} at 3.245 GeV. The missing mass spectra for both H and D are fitted with Monte-Carlo simulations incorporating peaks corresponding to {Lambda} production on the proton and {Sigma} production on both the proton and neutron. For D, the cross section ratio {Sigma}{sup 0}/{Sigma}{sup {minus}} {approx} 2, and excess yield close to the thresholds for {Lambda} and {Sigma} production can be attributed to final-state interactions that are compared to the data. The analysis of the data for the He targets is in a more preliminary state with broader quasi-free peaks resulting from the higher Fermi momenta. Evidence for bound {Lambda}-hypernuclear states is seen and other structure may be present.

Published
2001

5. Electroproduction of kaons and light hypernuclei

Author

John C. Mitchell, Y. Liang, T. Eden, Thomas O'Neill, D. F. Geesaman, R. E. Segel, L. Ewell, J. Cha, H. Bitao, E. Christy, Ketevi Assamagan, M. Sarsour, J. Crowder, L. Cole, J. W. Price, S. Danagoulian, Dipangkar Dutta, H. Juengst, H. Yamaguchi, H.T. Fortune, D. Koltenuk, N. Chant, J. H. Liu, D. Abbott, R. Asaturyan, D. G. Meekins, W. Hinton, T. Miyoshi, J. Roche, Brian Raue, Paul Gueye, W. U. Boeglin, J. Reinhold, Pete Markowitz, J.-O. Hansen, L. G. Tang, R. Mohring, R. Sawafta, K. Garrow, J. P. Schiffer, C. E. Keppel, C. J. Martoff, C. Cothran, John Arrington, Kevin Bailey, C. Yan, B. Zihlmann, H. C. Fenker, B. Terburg, C. S. Armstrong, P. Roos, Y. Sato, Rolf Ent, S. Tajima, B. Mueller, P. Ambrozewicz, G. Savage, S. Stepanyan, D. S. Brown, A. Uzzle, O. K. Baker, Avraham Klein, A. Cochran, H. Mkrtchyan, A. Semenov, L. Gan, W. J. Cummings, G. Collins, F. Duncan, K. Gustafsson, F. Dohrmann, Y. Fujii, R. Madey, M. Zeier, J. A. Dunne, A. Ahmidouch, R. D. Carlini, S. A. Wood, A. F. Lung, D. J. Mack, L. Yuan, S. Beedoe, M. Elaasar, Stephen Avery, G. Niculescu, I. Niculescu, D. Potterveld, V. Tadevosian, S. Mtingwa, H. Breuer, K. Hafidi, Haiyan Gao, H. E. Jackson, P. E. Reimer, B. Zeidman, and (Astro)-Particles Physics

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Deuterium, Production (computer science), Electron, Nucleon, Fundamental interaction
Abstract

A detailed investigation of the basic hyperon-nucleon interactions in nuclei is one of the aims of Experiment 91-016, approved with high priority at CEBAF, to study the electroproduction of kaons on targets of deuterium, {sup 3}He, and {sup 4}He. Inasmuch as both the electron and K{sup +} are particles that interact relatively weakly with nucleons, electroproduction of light hypernuclei provides a low-distortion method for investigating the fundamental interactions between nucleons, {Alpha}`s, and {Epsilon}`s in few-body systems. In particular, the (e,e`K{sup +}) reactions on cryogenic targets of D, {sup 3}He, and {sup 4}He will be studied at incident electron energies near 3 GeV with coincident detection of the emergent e and K{sup +} in the HMS and SOS magnetic spectrometers in Hall C. Construction of the He target, operating at {approximately}10 atm, {approximately}50 K and capable of dissipating {approximately}30 W, is expected to be complete prior to commencement of production runs in Hall C. The first data runs for E91-016, expected to begin late in FY 1995, will also be the basis for a doctoral thesis at Hampton University. In addition to providing new information on the phases of hyperon-nucleon interactions, measurements of cross sections for hypernuclear formation, and interference phenomena,more » the data may provide evidence for the presence of bound {Epsilon}`s and strange di-baryonic states that are the subject of considerable theoretical discussion.« less

Published
2001

6. Evidence for Valencelike Quark-Hadron Duality

Author

W. F. Vulcan, C. Yan, I. Niculescu, S. A. Wood, J. H. Mitchell, Paul Gueye, John Arrington, D. J. Mack, P. Stoler, J. W. Price, H. E. Jackson, Donal Day, C. E. Keppel, B. Terburg, J. Reinhold, V. Frolov, D. G. Meekins, L. G. Tang, Rolf Ent, D. Koltenuk, C. S. Armstrong, J. Cha, Dipangkar Dutta, C. Bochna, R. E. Segel, R. D. Carlini, D. van Westrum, D. Potterveld, R. Mohring, G. Niculescu, C. Cothran, W. Hinton, R. J. Holt, D. F. Geesaman, Ketevi Assamagan, O. K. Baker, M. A. Miller, J. A. Dunne, Douglas H Beck, B. Zeidman, and Haiyan Gao

Subjects
Quantum chromodynamics, Quark, Physics, Particle physics, Scattering, Nuclear Theory, Hadron, General Physics and Astronomy, Elementary particle, Resonance (particle physics), Nuclear physics, Nuclear Experiment, Nucleon, Scaling
Abstract

A newly obtained data sample of inclusive electron-nucleon scattering from both hydrogen and deuterium targets is analyzed. These JLab data span the nucleon resonance region up to four-momentum transfers of 5 (GeV/c){sup 2} . The data are found to follow an average scaling curve. The inclusion of low-momentum transfer data yields a scaling curve resembling deep inelastic neutrino-nucleus scattering data, suggesting a sensitivity to valencelike structure only. (c) 2000 The American Physical Society.

Published
2000

7. Longitudinal and Transverse Cross Sections in the1H(e,e′K+)ΛReaction

Author

G. Niculescu, R. M. Mohring, P. Gueye, D. Abbott, A. Ahmidouch, Ts. A. Amatuni, P. Ambrozewicz, T. Angelescu, C. S. Armstrong, K. Assamagan, S. Avery, K. Bailey, O. K. Baker, K. Beard, S. Beedoe, E. Beise, H. Breuer, R. Carlini, J. Cha, C. C. Chang, N. Chant, E. Cisbani, G. Collins, W. Cummings, S. Danagoulian, R. De Leo, F. Duncan, J. Dunne, D. Dutta, T. Eden, R. Ent, L. Eyraud, L. Ewell, M. Finn, T. Fortune, V. Frolov, S. Frullani, C. Furget, F. Garibaldi, D. Gaskell, D. F. Geesaman, K. K. Gustafsson, J.-O. Hansen, M. Harvey, W. Hinton, E. Hungerford, M. Iodice, C. Jackson, C. Keppel, W. Kim, K. Kino, D. Koltenuk, S. Kox, L. Kramer, T. Leone, G. Lolos, A. Lung, D. Mack, R. Madey, M. Maeda, S. Majewski, P. Markowitz, C. J. Martoff, D. Meekins, A. Mihul, J. Mitchell, H. Mkrtchyan, S. Mtingwa, I. Niculescu, R. Perrino, D. Potterveld, J. W. Price, B. A. Raue, J.-S. Real, J. Reinhold, P. Roos, T. Saito, G. Savage, R. Sawafta, R. Segel, S. Stepanyan, P. Stoler, V. Tadevosian, L. Tang, L. Teodorescu, T. Terasawa, H. Tsubota, G. M. Urciuoli, J. Volmer, W. Vulcan, P. Welch, R. Williams, S. Wood, C. Yan, and B. Zeidman

Subjects
Nuclear physics, Physics, Transverse plane, Science and engineering, General Physics and Astronomy, Lambda
Abstract

U.S. Department of Energy, National Science Foundation, Stichting voor Fundamenteel Onderzoek der Materie (Netherlands), Korean Science and Engineering Foundation

Published
1998

8. 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

9. High energy deuteron photodisintegration

Author

J. Napolitano, S.J. Freedman, D.F. Geesaman, R. Gilman, M.C. Green, R.J. Holt, H.E. Jackson, E.R. Kinney, R. Kowalczyk, C. Marchand, J. Nelson, D. Potterveld, B. Zeidman, R.E. Segel, T.-Y. Tung, D. Beck, G. Boyd, D. Collins, B.W. Filippone, J. Jourdan, R.D. McKeown, R. Milner, R. Walker, C. Woodward, P.E. Bosted, Z.-E. Meziani, and R. Minehart

Subjects
Quark, Physics, Nuclear and High Energy Physics, Particle physics, High energy, High Energy Physics::Phenomenology, Nuclear Theory, Hadron, Degrees of freedom (physics and chemistry), Nuclear physics, Low energy, Deuterium, Photodisintegration, Nuclear Experiment
Abstract

I discuss the issue of the “transition” between hadronic and quark degrees of freedom. I review the pertinent existing world data concerning this issue, particularly in low energy deuteron photodisintegration, including new unpublished results.

Published
1990

10. Determination of the pion charge form factor at Q2=1.60 and 2.45 (GeV/c)2

Author

T, Horn, K, Aniol, J, Arrington, B, Barrett, E J, Beise, H P, Blok, W, Boeglin, E J, Brash, H, Breuer, C C, Chang, M E, Christy, R, Ent, D, Gaskell, E, Gibson, R J, Holt, G M, Huber, S, Jin, M K, Jones, C E, Keppel, W, Kim, P M, King, V, Kovaltchouk, J, Liu, G J, Lolos, D J, Mack, D J, Margaziotis, P, Markowitz, A, Matsumura, D, Meekins, T, Miyoshi, H, Mkrtchyan, I, Niculescu, Y, Okayasu, L, Pentchev, C, Perdrisat, D, Potterveld, V, Punjabi, P, Reimer, J, Reinhold, J, Roche, P G, Roos, A, Sarty, G R, Smith, V, Tadevosyan, L G, Tang, V, Tvaskis, S, Vidakovic, J, Volmer, W, Vulcan, G, Warren, S A, Wood, C, Xu, and X, Zheng

Abstract

The 1H(e,e'pi+)n cross section was measured at four-momentum transfers of Q2=1.60 and 2.45 GeV2 at an invariant mass of the photon nucleon system of W=2.22 GeV. The charged pion form factor (F(pi)) was extracted from the data by comparing the separated longitudinal pion electroproduction cross section to a Regge model prediction in which F(pi) is a free parameter. The results indicate that the pion form factor deviates from the charge-radius constrained monopole form at these values of Q2 by one sigma, but is still far from its perturbative quantum chromodynamics prediction.

Published
2006

11. Angular distributions for (3,4)(Lambda)H bound states in the (3,4)He(e,e(')K+) reaction

Author

F, Dohrmann, A, Ahmidouch, C S, Armstrong, J, Arrington, R, Asaturyan, S, Avery, K, Bailey, H, Bitao, H, Breuer, D S, Brown, R, Carlini, J, Cha, N, Chant, E, Christy, A, Cochran, L, Cole, J, Crowder, S, Danagoulian, M, Elaasar, R, Ent, H, Fenker, Y, Fujii, L, Gan, K, Garrow, D F, Geesaman, P, Gueye, K, Hafidi, W, Hinton, H, Juengst, C, Keppel, Y, Liang, J H, Liu, A, Lung, D, Mack, P, Markowitz, J, Mitchell, T, Miyoshi, H, Mkrtchyan, S K, Mtingwa, B, Mueller, G, Niculescu, I, Niculescu, D, Potterveld, B A, Raue, P E, Reimer, J, Reinhold, J, Roche, M, Sarsour, Y, Sato, R E, Segel, A, Semenov, S, Stepanyan, V, Tadevosian, S, Tajima, L, Tang, A, Uzzle, S, Wood, H, Yamaguchi, C, Yan, L, Yuan, B, Zeidman, M, Zeier, and B, Zihlmann

Abstract

The (3,4)(Lambda)H and (4)(Lambda)H hypernuclear bound states have been observed for the first time in kaon electroproduction on (3,4)He targets. The production cross sections have been determined at Q(2)=0.35 GeV2 and W=1.91 GeV. For either hypernucleus the nuclear form factor is determined by comparing the angular distribution of the (3,4)He(e,e(')K+)(3,4)(Lambda)H processes to the elementary cross section 1H(e,e K+)Lambda on the free proton, measured during the same experiment.

Published
2004

12. Electroproduction of Strangeness on Light Nuclei

Author

F. DOHRMANN, D. ABBOTT, A. AHMIDOUCH, P. AMBROZEWICZ, C.S. ARMSTRONG, J. ARRINGTON, R. ASATURYAN, K. ASSAMAGAN, S. AVERY, K. BAILEY, O.K. BAKER, S. BEEDOE, H. BITAO, H. BREUER, D.S. BROWN, R. CARLINI, J. CHA, N. CHANT, E. CHRISTY, A. COCHRAN, L. COLE, G. COLLINS, C. COTHRAN, J. CROWDER, W.J. CUMMINGS, S. DANAGOULIAN, F. DUNCAN, J. DUNNE, D. DUTTA, T. EDEN, M. ELAASAR, R. ENT, L. EWELL, H. FENKER, H.T. FORTUNE, Y. FUJII, L. GAN, H. GAO, K. GARROW, D.F. GEESAMAN, P. GUEYE, K. GUSTAFSSON, K. HAFIDI, J.O. HANSEN, W. HINTON, H.E. JACKSON, H. JUENGST, C. KEPPEL, A. KLEIN, D. KOLTENUK, Y. LIANG, J.H. LIU, A. LUNG, D. MACK, R. MADEY, P. MARKOWITZ, C.J. MARTOFF, D. MEEKINS, J. MITCHELL, T. MIYOSHI, H. MKRTCHYAN, R. MOHRING, S.K. MTINGWA, B. MUELLER, T.G. O’NEILL, G. NICULESCU, I. NICULESCU, D. POTTERVELD, J.W. PRICE, B.A. RAUE, P.E. REIMER, J. REINHOLD, J. ROCHE, P. ROOS, M. SARSOUR, Y. SATO, G. SAVAGE, R. SAWAFTA, R.E. SEGEL, A.YU. SEMENOV, S. STEPANYAN, V. TADEVOSIAN, S. TAJIMA, L. TANG, B. TERBURG, A. UZZLE, S. WOOD, H. YAMAGUCHI, C. YAN, L. YUAN, M. ZEIER, B. ZEIDMAN, and B. ZIHLMANN

Subjects
Physics, Light nucleus, Electroproduction, Nuclear Theory, Strangeness, Hyperons, Spectral function, Nuclear physics, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, Nuclear Experiment, Hypernuclear boundstates, Electroproduction of strangeness, Nuclear targets
Abstract

The A(e,e'K+)YX reaction has been investigated in Hall C at Jefferson Laboratory for 6 different targets. Data were taken for Q2)approx 0.35 and 0.5 GeV2) at a beam energy of 3.245GeV for 1)H, 2)H, 3)He, 4)He, C and Al targets. The missing mass spectra are fitted with Monte Carlo simulations taking into account the production of Lambda and Sigma0) hyperon production off the proton, and Sigma-) off the neutron. Models for quasifree production are compared to the data, excess yields close to threshold are attributed to FSI. Evidence for Lambda-hypernuclear bound states is seen for 3,4)He targets.

Published
2004

13. Quasielastic(e,e′p)reaction onC12,Fe56, andAu197

Author

D. Dutta, D. van Westrum, D. Abbott, A. Ahmidouch, Ts. A. Amatuoni, C. Armstrong, J. Arrington, K. A. Assamagan, K. Bailey, O. K. Baker, S. Barrow, K. Beard, D. Beatty, S. Beedoe, E. Beise, E. Belz, C. Bochna, P. E. Bosted, H. Breuer, E. E. W. Bruins, R. Carlini, J. Cha, N. Chant, C. Cothran, W. J. Cummings, S. Danagoulian, D. Day, D. DeSchepper, J.-E. Ducret, F. Duncan, J. Dunne, T. Eden, R. Ent, H. T. Fortune, V. Frolov, D. F. Geesaman, H. Gao, R. Gilman, P. Guèye, J. O. Hansen, W. Hinton, R. J. Holt, C. Jackson, H. E. Jackson, C. Jones, S. Kaufman, J. J. Kelly, C. Keppel, M. Khandaker, W. Kim, E. Kinney, A. Klein, D. Koltenuk, L. Kramer, W. Lorenzon, A. Lung, K. McFarlane, D. J. Mack, R. Madey, P. Markowitz, J. Martin, A. Mateos, D. Meekins, M. A. Miller, R. Milner, J. Mitchell, R. Mohring, H. Mkrtchyan, A. M. Nathan, G. Niculescu, I. Niculescu, T. G. O’Neill, D. Potterveld, J. W. Price, J. Reinhold, C. Salgado, J. P. Schiffer, R. E. Segel, P. Stoler, R. Suleiman, V. Tadevosyan, L. Tang, B. Terburg, T. P. Welch, C. Williamson, S. Wood, C. Yan, J.-C. Yang, J. Yu, B. Zeidman, W. Zhao, and B. Zihlmann

Subjects
Physics, Nuclear and High Energy Physics, Mathematical physics
Published
2003

14. HYPERON–NUCLEON BOUND STATES AND ELECTROPRODUCTION OF STRANGENESS ON LIGHT NUCLEI

Author

A. Ahmidouch, Haiyan Gao, D. Abbott, J. O. Hansen, B. Zeidman, D. F. Geesaman, F. Dohrmann, D. Potterveld, Thomas O'Neill, H. E. Jackson, W. J. Cummings, J. Arrington, C. S. Armstrong, P. Ambrozewicz, J. Reinhold, B. Mueller, K. Hafidi, K. Bailey, P. E. Reimer, and K. Garrow

Subjects
Physics, Particle physics, Meson, Hadron, Hyperon, Production (computer science), Strangeness, Lambda baryon, Nucleon, Sigma baryon
Abstract

The A(e,e{prime}K{sup +})Y X reaction has been investigated in Hall C at Jefferson Lab. Data were taken for Q{sup 2} {approx} 0.35 and 0.5 GeV{sup 2} at a beam energy of 3.245 GeV for {sup 1}H, {sup 2}H, {sup 3}He and {sup 4}He, C and Al targets. The missing mass spectra are fitted with Monte Carlo simulations including {Lambda}, {Sigma}{sup 0}, {Sigma}{sup -} hyperon production. Models for quasifree production are compared to the data, excess yields close to threshold are attributed to FSI. Evidence for {Lambda}-hypernuclear bound states is seen for {sup 3,4}He targets.

Published
2003

15. Nuclear transparency from quasielasticA(e,e′p)reactions up toQ2=8.1(GeV/c)2

Author

K. Garrow, D. McKee, A. Ahmidouch, C. S. Armstrong, J. Arrington, R. Asaturyan, S. Avery, O. K. Baker, D. H. Beck, H. P. Blok, C. W. Bochna, W. Boeglin, P. Bosted, M. Bouwhuis, H. Breuer, D. S. Brown, A. Bruell, R. D. Carlini, N. S. Chant, A. Cochran, L. Cole, S. Danagoulian, D. B. Day, J. Dunne, D. Dutta, R. Ent, H. C. Fenker, B. Fox, L. Gan, D. Gaskell, A. Gasparian, H. Gao, D. F. Geesaman, R. Gilman, P. L. J. Guèye, M. Harvey, R. J. Holt, X. Jiang, C. E. Keppel, E. Kinney, Y. Liang, W. Lorenzon, A. Lung, D. J. Mack, P. Markowitz, J. W. Martin, K. McIlhany, D. Meekins, M. A. Miller, R. G. Milner, J. H. Mitchell, H. Mkrtchyan, B. A. Mueller, A. Nathan, G. Niculescu, I. Niculescu, T. G. O’Neill, V. Papavassiliou, S. Pate, R. B. Piercey, D. Potterveld, R. D. Ransome, J. Reinhold, E. Rollinde, P. Roos, A. J. Sarty, R. Sawafta, E. C. Schulte, E. Segbefia, C. Smith, S. Stepanyan, S. Strauch, V. Tadevosyan, L. Tang, R. Tieulent, A. Uzzle, W. F. Vulcan, S. A. Wood, F. Xiong, L. Yuan, M. Zeier, B. Zihlmann, and V. Ziskin

Subjects
Nuclear physics, Mass number, Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Range (particle radiation), Deuterium, Nuclear transparency, Momentum transfer, Color transparency, Energy (signal processing)
Abstract

The quasielastic (e,e'p) reaction was studied on targets of deuterium, carbon, and iron up to a value of momentum transfer Q{sup 2} of 8.1 (GeV/c){sup 2}. A nuclear transparency was determined by comparing the data to calculations in the Plane-Wave Impulse Approximation. The dependence of the nuclear transparency on Q{sup 2} and the mass number A was investigated in a search for the onset of the Color Transparency within our range of Q{sup 2}. A fit to the world's nuclear transparency data reflects the energy dependence of the free proton-nucleon cross section.

Published
2002

16. Longitudinal Electroproduction of Charged Pions fromH1,H2, andH3e

Author

A. Cowley, P. Ambrozewicz, Ronald Gilman, P. Roos, D. Van Westrum, R. Carlini, B. Beise, B. Zeidman, D. McKee, P. Gueye, H. Anklin, C. Jackson, D. Dutta, D. S. Brown, O. Hashimoto, J. Cha, R. Segel, M. Harvey, A. Lung, R. Ent, J. Mitchell, A. Gasparian, T. Takahashi, L. Yuan, L. Gan, T. G. O'Neill, D. Potterveld, I. Niculescu, T. P. Welch, Stephen Avery, B. Zihlmann, H. E. Jackson, J. Reinhold, D. F. Geesaman, H. Breuer, V. Papavassiliou, G. Kyle, S. Stepanyan, W. Hinton, G. Niculescu, N. Chant, J. Volmer, J. Arrington, D. Mack, K. Bailey, D. Koltenuk, V. Tadevosyan, D. De Schepper, C. Glashausser, E. Kinney, B. Mueller, O. K. Baker, B. Terburg, K. Assamagan, A. Ahmidouch, R. Sawafta, D. Gaskell, James Dunne, L. Tang, S. Danagoulian, G. Hofman, C. Keppel, H. Mkrtchyan, S. Beedoe, and S. Wood

Subjects
Physics, Particle physics, Meson, Nuclear Theory, Hadron, General Physics and Astronomy, Fermi surface, Elementary particle, Nuclear physics, Pion, Recoil, High Energy Physics::Experiment, Invariant mass, Nuclear Experiment, Boson
Abstract

Separated longitudinal and transverse cross sections for charged pion electroproduction from (1)H, (2)H, and (3)He were measured at Q(2) = 0.4 (GeV/c)(2) for two values of the invariant mass, W = 1.15 GeV and W = 1.60 GeV, in a search for a mass dependence which would signal the effect of nuclear pions. This is the first such study that includes recoil momenta significantly above the Fermi surface. The longitudinal cross section, if dominated by the pion-pole process, should be sensitive to nuclear pion currents. Comparisons of the longitudinal cross section target ratios to a quasifree calculation reveal a significant suppression in (3)He at W = 1.60 GeV. The W = 1.15 GeV results are consistent with simple estimates of the effect of nuclear pion currents, but are also consistent with pure quasifree production.

Published
2001

17. Measurement of the Charged Pion Electromagnetic Form Factor

Author

J. Volmer, D. Abbott, H. Anklin, C. Armstrong, J. Arrington, K. Assamagan, S. Avery, O. K. Baker, H. P. Blok, C. Bochna, E. J. Brash, H. Breuer, N. Chant, J. Dunne, T. Eden, R. Ent, D. Gaskell, R. Gilman, K. Gustafsson, W. Hinton, G. M. Huber, H. Jackson, M. K. Jones, C. Keppel, P. H. Kim, W. Kim, A. Klein, D. Koltenuk, M. Liang, G. J. Lolos, A. Lung, D. J. Mack, D. McKee, D. Meekins, J. Mitchell, H. Mkrtchyan, B. Mueller, G. Niculescu, I. Niculescu, D. Pitz, D. Potterveld, L. M. Qin, J. Reinhold, I. K. Shin, S. Stepanyan, V. Tadevosyan, L. G. Tang, R. L. J. van der Meer, K. Vansyoc, D. Van Westrum, W. Vulcan, S. Wood, C. Yan, W.-X. Zhao, B. Zihlmann, and (Astro)-Particles Physics

Subjects
Physics, Particle physics, 010308 nuclear & particles physics, Momentum transfer, Form factor (quantum field theory), Magnetic monopole, FOS: Physical sciences, General Physics and Astronomy, Charge (physics), 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Transverse plane, Cross section (physics), Pion, 0103 physical sciences, High Energy Physics::Experiment, Invariant mass, Nuclear Experiment (nucl-ex), Nuclear Experiment, 010306 general physics
Abstract

Separated longitudinal and transverse structure functions for the reaction 1H(e,eprime pi+)n were measured in the momentum transfer region Q2=0.6-1.6 (GeV/c)**2 at a value of the invariant mass W=1.95 GeV. New values for the pion charge form factor were extracted from the longitudinal cross section by using a recently developed Regge model. The results indicate that the pion form factor in this region is larger than previously assumed and is consistent with a monopole parameterization fitted to very low Q2 elastic data., Comment: 5 pages, 3 figures

Published
2001

18. Experimental Verification of Quark-Hadron Duality

Author

S. A. Wood, D. Koltenuk, C. S. Armstrong, R. J. Holt, D. van Westrum, B. W. Filippone, D. J. Mack, J. Reinhold, B. Zeidman, Paul Gueye, John Arrington, J. A. Dunne, C. E. Keppel, C. Cothran, G. Niculescu, L. G. Tang, R. E. Segel, R. D. Carlini, Douglas H Beck, Rolf Ent, W. F. Vulcan, Donal Day, R. Mohring, B. Terburg, Haiyan Gao, W. Hinton, C. Bochna, P. Stoler, D. G. Meekins, J. H. Mitchell, J. W. Price, J. Cha, Dipangkar Dutta, D. F. Geesaman, D. Potterveld, I. Niculescu, O. K. Baker, Ketevi Assamagan, H. E. Jackson, V. Frolov, M. A. Miller, and C. Yan

Subjects
Quark, Physics, Particle physics, Hadron, Nuclear Theory, General Physics and Astronomy, Duality (optimization), Elementary particle, Resonance (particle physics), Nuclear physics, Magnetic form factor, Twist, Nucleon, Nuclear Experiment, Caltech Library Services
Abstract

A newly-obtained sample of inclusive electron-nucleon scattering data has been analyzed for precision tests of quark-hadron duality. The data are in the nucleon resonance region, and span the range 0.3 < Q{sup 2} < 5.0 (GeV/c){sup 2}. Duality is observed both in limited and extended regions around the prominent resonance enhancements. Higher twist contributions to the F{sub 2} structure function are found to be minimal on average, even in the low Q{sub 2} regime of approximately 0.5 (GeV/c){sup 2}. The proton magnetic form factor, extracted from purely inelastic data assuming duality, is in good agreement with the direct measurements. In all cases, duality appears to be a non-trivial property of the nucleon structure function.

Published
2000

19. DAD - Distributed Adamo Database system at Hermes

Author

M. A. Funk, M. Düren, P.W. Green, K. Ackerstaff, P. Welch, P. Oelwein, W. Wander, M. Ferstl, and D. Potterveld

Subjects
World Wide Web, Physics, Data processing, Operating system, computer.software_genre, computer
Published
1996

20. A study of the nuclear and kinematic dependence of R = σL/σT in deep inelastic electron scattering

Author

L.W. Whitlow, J. Button-Shafer, P. de Barbaro, M. W. Krasny, R. D. Mckeown, B. W. Filippone, A. Bodek, Karol Lang, S. E. Rock, R. Milner, P. E. Bosted, R. S. Hicks, R. G. Arnold, H. Harada, G. De Chambrier, S. Dasu, A. Lung, F. S. Dietrich, E. M. Riordan, R. C. Walker, B. Debfbe, L. Clogher, J. Jourdan, A. Para, K. Van Bibber, R. A. Gearhart, D. Benton, J. Alster, D. Potterveld, and Z. M. Szalata

Subjects
Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Range (particle radiation), Large Hadron Collider, Nuclear Theory, EMC effect, Nuclear physics, Cross section (physics), Deuterium, High Energy Physics::Experiment, Atomic physics, Twist, Nuclear Experiment, Nucleon
Abstract

We report preliminary results on the nuclear dependence of R = σL/σT in the deep inelastic electron scattering from deuterium, iron, and gold nuclei. In the x, Q2 range of 0.2 ⩽ x ⩽ 0.5 and 1 ⩽ Q2 ⩽ 5 (GeV/c)2, the average RFe − RD is 0.03 ± 0.02 (stat) ± 0.06 (syst); the final systematic errors are expected to be reduced to ± 0.03. The results indicate that there are no significant spin-0 constituents or higher twist effects in nuclei as compared to free nucleons. Models for the EMC effect with significant nuclear dependence of R are ruled out. The discrepancy, at low x, between CERN and SLAC results for the cross section ratio σFe/σD cannot be attributed to a nuclear dependence of R as suggested by some authors. The kinematic variation of RD with x and Q2 in the SLAC energy is in agreement with the predictions of QCD with the addition of target mass effects.

Published
1988

21. Measurement of the high energy two-body deuteron photodisintegration differential cross section

Author

S. A. Wood, H. C. Fenker, Pete Markowitz, K. McIlhany, Thomas O'Neill, D. J. Mack, Raphael Noel Tieulent, R. J. Holt, X. Jiang, Stephen Avery, D. F. Geesaman, H. P. Blok, Paul Gueye, Alan M. Nathan, E. R. Kinney, V. Ziskin, Dipanwita Dutta, L. Cole, Wolfgang Lorenzon, F. Xiong, C. E. Keppel, Haiyan Gao, B. D. Fox, J. Reinhold, S. Stepanyan, G. Niculescu, P. G. Roos, M. Harvey, A. Bruell, Douglas H Beck, H. Breuer, Arijit Saha, M. A. Miller, L. G. Tang, R. Sawafta, R. V. Cadman, M. Bouwhuis, B. Mueller, S. F. Pate, H. Mkrtchyan, D. Potterveld, A. Ahmidouch, Y. Liang, I. Niculescu, John Arrington, S. Strauch, Ronald Gilman, M. Zeier, E. Rollinde, V. Papavassiliou, L. Yuan, W. F. Vulcan, N. S. Chant, A. Uzzle, Ronald Ransome, J. H. Mitchell, E. Segbefia, L. Gan, Charles Glashausser, J. W. Martin, R. B. Piercey, D. Meekins, H. E. Jackson, W. U. Boeglin, V. Tadevosyan, A. J. Sarty, Ross Milner, M. Sutter, J. A. Dunne, P. Bosted, K. Garrow, A. Lung, Rolf Ent, B. Zihlmann, T. Shin, D. S. Brown, A. Gasparian, A. Cochran, C. Bochna, C. S. Armstrong, D. McKee, O. K. Baker, Donal Day, S. Danagoulian, R. D. Carlini, E. Schulte, David Gaskell, R. Asaturyan, and (Astro)-Particles Physics

Subjects
Physics, Nuclear reaction, Particle physics, Astrophysics::High Energy Astrophysical Phenomena, Hadron, General Physics and Astronomy, Particle accelerator, Elementary particle, law.invention, Baryon, Nuclear physics, law, Photodisintegration, Neutron, Nuclear Experiment, Nucleon
Abstract

The first measurements of the d(gamma,p)n differential cross section at forward angles and photon energies above 4 GeV were performed at the Thomas Jefferson National Accelerator Facility (JLab). The results indicate evidence of an angular dependent scaling threshold. Results at straight theta(cm) = 37 degrees are consistent with the constituent counting rules for E(gamma) greater, similar 4 GeV, while those at 70 degrees are consistent with the constituent counting rules for E(gamma) greater, similar 1.5 GeV.

22. Solving the Puzzles of the Decay of the Heaviest Known Proton-Emitting Nucleus ^{185}Bi.

Author

Doherty DT, Andreyev AN, Seweryniak D, Woods PJ, Carpenter MP, Auranen K, Ayangeakaa AD, Back BB, Bottoni S, Canete L, Cubiss JG, Harker J, Haylett T, Huang T, Janssens RVF, Jenkins DG, Kondev FG, Lauritsen T, Lederer-Woods C, Li J, Müller-Gatermann C, Potterveld D, Reviol W, Savard G, Stolze S, and Zhu S

Abstract

Two long-standing puzzles in the decay of ^{185}Bi, the heaviest known proton-emitting nucleus are revisited. These are the nonobservation of the 9/2^{-} state, which is the ground state of all heavier odd-A Bi isotopes, and the hindered nature of proton and α decays of its presumed 60-μs 1/2^{+} ground state. The ^{185}Bi nucleus has now been studied with the ^{95}Mo(^{93}Nb,3n) reaction in complementary experiments using the Fragment Mass Analyzer and Argonne Gas-Filled Analyzer at Argonne National Laboratory's ATLAS facility. The experiments have established the existence of two states in ^{185}Bi; the short-lived T&#95;{1/2}=2.8&#95;{-1.0}^{+2.3}  μs, proton- and α-decaying ground state, and a 58(2)-μs γ-decaying isomer, the half-life of which was previously attributed to the ground state. The reassignment of the ground-state lifetime results in a proton-decay spectroscopic factor close to unity and represents the only known example of a ground-state proton decay to a daughter nucleus (^{184}Pb) with a major shell closure. The data also demonstrate that the ordering of low- and high-spin states in ^{185}Bi is reversed relative to the heavier odd-A Bi isotopes, with the intruder-based 1/2^{+} configuration becoming the ground, similar to the lightest At nuclides.

Published
2021
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23. Unique Access to u-Channel Physics: Exclusive Backward-Angle Omega Meson Electroproduction.

Author

Li WB, Huber GM, Blok HP, Gaskell D, Horn T, Semenov-Tian-Shansky K, Pire B, Szymanowski L, Laget JM, Aniol K, Arrington J, Beise EJ, Boeglin W, Brash EJ, Breuer H, Chang CC, Christy ME, Ent R, Gibson EF, Holt RJ, Jin S, Jones MK, Keppel CE, Kim W, King PM, Kovaltchouk V, Liu J, Lolos GJ, Mack DJ, Margaziotis DJ, Markowitz P, Matsumura A, Meekins D, Miyoshi T, Mkrtchyan H, Niculescu I, Okayasu Y, Pentchev L, Perdrisat C, Potterveld D, Punjabi V, Reimer PE, Reinhold J, Roche J, Roos PG, Sarty A, Smith GR, Tadevosyan V, Tang LG, Tvaskis V, Volmer J, Vulcan W, Warren G, Wood SA, Xu C, and Zheng X

Abstract

Backward-angle meson electroproduction above the resonance region, which was previously ignored, is anticipated to offer unique access to the three quark plus sea component of the nucleon wave function. In this Letter, we present the first complete separation of the four electromagnetic structure functions above the resonance region in exclusive ω electroproduction off the proton, ep→e^{'}pω, at central Q^{2} values of 1.60, 2.45  GeV^{2}, at W=2.21  GeV. The results of our pioneering -u≈-u&#95;{min} study demonstrate the existence of a unanticipated backward-angle cross section peak and the feasibility of full L/T/LT/TT separations in this never explored kinematic territory. At Q^{2}=2.45  GeV^{2}, the observed dominance of σ&#95;{T} over σ&#95;{L}, is qualitatively consistent with the collinear QCD description in the near-backward regime, in which the scattering amplitude factorizes into a hard subprocess amplitude and baryon to meson transition distribution amplitudes: universal nonperturbative objects only accessible through backward-angle kinematics.

Published
2019
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24. Fission barrier of superheavy nuclei and persistence of shell effects at high spin: cases of 254No and 220Th.

Author

Henning G, Khoo TL, Lopez-Martens A, Seweryniak D, Alcorta M, Asai M, Back BB, Bertone PF, Boilley D, Carpenter MP, Chiara CJ, Chowdhury P, Gall B, Greenlees PT, Gürdal G, Hauschild K, Heinz A, Hoffman CR, Janssens RV, Karpov AV, Kay BP, Kondev FG, Lakshmi S, Lauritsen T, Lister CJ, McCutchan EA, Nair C, Piot J, Potterveld D, Reiter P, Rogers AM, Rowley N, and Zhu S

Abstract

We report on the first measurement of the fission barrier height in a heavy shell-stabilized nucleus. The fission barrier height of 254No is measured to be Bf=6.0±0.5  MeV at spin 15ℏ and, by extrapolation, Bf=6.6±0.9  MeV at spin 0ℏ. This information is deduced from the measured distribution of entry points in the excitation energy versus spin plane. The same measurement is performed for 220Th and only a lower limit of the fission barrier height can be determined: Bf(I)>8  MeV. Comparisons with theoretical fission barriers test theories that predict properties of superheavy elements.

Published
2014
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25. Separated response function ratios in exclusive, forward π(±) electroproduction.

Author

Huber GM, Blok HP, Butuceanu C, Gaskell D, Horn T, Mack DJ, Abbott D, Aniol K, Anklin H, Armstrong C, Arrington J, Assamagan K, Avery S, Baker OK, Barrett B, Beise EJ, Bochna C, Boeglin W, Brash EJ, Breuer H, Chang CC, Chant N, Christy ME, Dunne J, Eden T, Ent R, Fenker H, Gibson EF, Gilman R, Gustafsson K, Hinton W, Holt RJ, Jackson H, Jin S, Jones MK, Keppel CE, Kim PH, Kim W, King PM, Klein A, Koltenuk D, Kovaltchouk V, Liang M, Liu J, Lolos GJ, Lung A, Margaziotis DJ, Markowitz P, Matsumura A, McKee D, Meekins D, Mitchell J, Miyoshi T, Mkrtchyan H, Mueller B, Niculescu G, Niculescu I, Okayasu Y, Pentchev L, Perdrisat C, Pitz D, Potterveld D, Punjabi V, Qin LM, Reimer PE, Reinhold J, Roche J, Roos PG, Sarty A, Shin IK, Smith GR, Stepanyan S, Tang LG, Tadevosyan V, Tvaskis V, van der Meer RL, Vansyoc K, Van Westrum D, Vidakovic S, Volmer J, Vulcan W, Warren G, Wood SA, Xu C, Yan C, Zhao WX, Zheng X, and Zihlmann B

Abstract

The study of exclusive π(±) electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio RL=σL(π-)/σL(π+) is sensitive to isoscalar contamination to the dominant isovector pion exchange amplitude, which is the basis for the determination of the charged pion form factor from electroproduction data. A change in the value of RT=σT(π-)/σT(π+) from unity at small -t, to 1/4 at large -t, would suggest a transition from coupling to a (virtual) pion to coupling to individual quarks. Furthermore, the mentioned ratios may show an earlier approach to perturbative QCD than the individual cross sections. We have performed the first complete separation of the four unpolarized electromagnetic structure functions above the dominant resonances in forward, exclusive π(±) electroproduction on the deuteron at central Q(2) values of 0.6, 1.0, 1.6  GeV(2) at W=1.95  GeV, and Q(2)=2.45  GeV(2) at W=2.22  GeV. Here, we present the L and T cross sections, with emphasis on RL and RT, and compare them with theoretical calculations. Results for the separated ratio RL indicate dominance of the pion-pole diagram at low -t, while results for RT are consistent with a transition between pion knockout and quark knockout mechanisms.

Published
2014
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26. Determination of the pion charge form factor at Q2=1.60 and 2.45 (GeV/c)2.

Author

Horn T, Aniol K, Arrington J, Barrett B, Beise EJ, Blok HP, Boeglin W, Brash EJ, Breuer H, Chang CC, Christy ME, Ent R, Gaskell D, Gibson E, Holt RJ, Huber GM, Jin S, Jones MK, Keppel CE, Kim W, King PM, Kovaltchouk V, Liu J, Lolos GJ, Mack DJ, Margaziotis DJ, Markowitz P, Matsumura A, Meekins D, Miyoshi T, Mkrtchyan H, Niculescu I, Okayasu Y, Pentchev L, Perdrisat C, Potterveld D, Punjabi V, Reimer P, Reinhold J, Roche J, Roos PG, Sarty A, Smith GR, Tadevosyan V, Tang LG, Tvaskis V, Vidakovic S, Volmer J, Vulcan W, Warren G, Wood SA, Xu C, and Zheng X

Abstract

The 1H(e,e'pi+)n cross section was measured at four-momentum transfers of Q2=1.60 and 2.45 GeV2 at an invariant mass of the photon nucleon system of W=2.22 GeV. The charged pion form factor (F(pi)) was extracted from the data by comparing the separated longitudinal pion electroproduction cross section to a Regge model prediction in which F(pi) is a free parameter. The results indicate that the pion form factor deviates from the charge-radius constrained monopole form at these values of Q2 by one sigma, but is still far from its perturbative quantum chromodynamics prediction.

Published
2006
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27. Angular distributions for (3,4)(Lambda)H bound states in the (3,4)He(e,e(')K+) reaction.

Author

Dohrmann F, Ahmidouch A, Armstrong CS, Arrington J, Asaturyan R, Avery S, Bailey K, Bitao H, Breuer H, Brown DS, Carlini R, Cha J, Chant N, Christy E, Cochran A, Cole L, Crowder J, Danagoulian S, Elaasar M, Ent R, Fenker H, Fujii Y, Gan L, Garrow K, Geesaman DF, Gueye P, Hafidi K, Hinton W, Juengst H, Keppel C, Liang Y, Liu JH, Lung A, Mack D, Markowitz P, Mitchell J, Miyoshi T, Mkrtchyan H, Mtingwa SK, Mueller B, Niculescu G, Niculescu I, Potterveld D, Raue BA, Reimer PE, Reinhold J, Roche J, Sarsour M, Sato Y, Segel RE, Semenov A, Stepanyan S, Tadevosian V, Tajima S, Tang L, Uzzle A, Wood S, Yamaguchi H, Yan C, Yuan L, Zeidman B, Zeier M, and Zihlmann B

Abstract

The (3,4)(Lambda)H and (4)(Lambda)H hypernuclear bound states have been observed for the first time in kaon electroproduction on (3,4)He targets. The production cross sections have been determined at Q(2)=0.35 GeV2 and W=1.91 GeV. For either hypernucleus the nuclear form factor is determined by comparing the angular distribution of the (3,4)He(e,e(')K+)(3,4)(Lambda)H processes to the elementary cross section 1H(e,e K+)Lambda on the free proton, measured during the same experiment.

Published
2004
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28. Cross-section measurement of charged-pion photoproduction from hydrogen and deuterium.

Author

Zhu LY, Arrington J, Averett T, Beise E, Calarco J, Chang T, Chen JP, Chudakov E, Coman M, Clasie B, Crawford C, Dieterich S, Dohrmann F, Dutta D, Fissum K, Frullani S, Gao H, Gilman R, Glashausser C, Gomez J, Hafidi K, Hansen JO, Higinbotham DW, Holt RJ, De Jager CW, Jiang X, Kinney E, Kramer K, Kumbartzki G, LeRose J, Liyanage N, Mack D, Markowitz P, McCormick K, Meekins D, Meziani ZE, Michaels R, Mitchell J, Nanda S, Potterveld D, Ransome R, Reimer PE, Reitz B, Saha A, Schulte EC, Seely J, Sirca S, Strauch S, Sulkosky V, Vlahovic B, Weinstein LB, Wijesooriya K, Williamson CF, Wojtsekhowski B, Xiang H, Xiong F, Xu W, Zeng J, and Zheng X

Abstract

We have measured the differential cross section for the gamman-->pi(-)p and gammap-->pi(+)n reactions at theta(c.m.)=90 degrees in the photon energy range from 1.1 to 5.5 GeV at Jefferson Lab (JLab). The data at E(gamma) greater, similar 3.3 GeV exhibit a global scaling behavior for both pi(-) and pi(+) photoproduction, consistent with the constituent counting rule and the existing pi(+) photoproduction data. Possible oscillations around the scaling value are suggested by these new data. The data show enhancement in the scaled cross section at a center-of-mass energy near 2.2 GeV. The cross section ratio of exclusive pi(-) to pi(+) photoproduction at high energy is consistent with the prediction based on one-hard-gluon-exchange diagrams.

Published
2003
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29. Longitudinal electroproduction of charged pions from (1)H, (2)H, and (3)He.

Author

Gaskell D, Ahmidouch A, Ambrozewicz P, Anklin H, Arrington J, Assamagan K, Avery S, Bailey K, Baker OK, Beedoe S, Beise B, Breuer H, Brown DS, Carlini R, Cha J, Chant N, Cowley A, Danagoulian S, De Schepper D, Dunne J, Dutta D, Ent R, Gan L, Gasparian A, Geesaman DF, Gilman R, Glashausser C, Gueye P, Harvey M, Hashimoto O, Hinton W, Hofman G, Jackson C, Jackson HE, Keppel C, Kinney E, Koltenuk D, Kyle G, Lung A, Mack D, McKee D, Mitchell J, Mkrtchyan H, Mueller B, Niculescu G, Niculescu I, O'Neill TG, Papavassiliou V, Potterveld D, Reinhold J, Roos P, Sawafta R, Segel R, Stepanyan S, Tadevosyan V, Takahashi T, Tang L, Terburg B, Van Westrum D, Volmer J, Welch TP, Wood S, Yuan L, Zeidman B, and Zihlmann B

Abstract

Separated longitudinal and transverse cross sections for charged pion electroproduction from (1)H, (2)H, and (3)He were measured at Q(2) = 0.4 (GeV/c)(2) for two values of the invariant mass, W = 1.15 GeV and W = 1.60 GeV, in a search for a mass dependence which would signal the effect of nuclear pions. This is the first such study that includes recoil momenta significantly above the Fermi surface. The longitudinal cross section, if dominated by the pion-pole process, should be sensitive to nuclear pion currents. Comparisons of the longitudinal cross section target ratios to a quasifree calculation reveal a significant suppression in (3)He at W = 1.60 GeV. The W = 1.15 GeV results are consistent with simple estimates of the effect of nuclear pion currents, but are also consistent with pure quasifree production.

Published
2001
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30. Measurement of the charged pion electromagnetic form factor.

Author

Volmer J, Abbott D, Anklin H, Armstrong C, Arrington J, Assamagan K, Avery S, Baker OK, Blok HP, Bochna C, Brash EJ, Breuer H, Chant N, Dunne J, Eden T, Ent R, Gaskell D, Gilman R, Gustafsson K, Hinton W, Huber GM, Jackson H, Jones MK, Keppel C, Kim PH, Kim W, Klein A, Koltenuk D, Liang M, Lolos GJ, Lung A, Mack DJ, McKee D, Meekins D, Mitchell J, Mkrtchyan H, Mueller B, Niculescu G, Niculescu I, Pitz D, Potterveld D, Qin LM, Reinhold J, Shin IK, Stepanyan S, Tadevosyan V, Tang LG, van der Meer RL, Vansyoc K, Van Westrum D, Vulcan W, Wood S, Yan C, Zhao WX, and Zihlmann B

Abstract

Separated longitudinal and transverse structure functions for the reaction 1H(e,e(')pi(+))n were measured in the momentum transfer region Q2 = 0.6--1.6 (GeV/c)(2) at a value of the invariant mass W = 1.95 GeV. New values for the pion charge form factor were extracted from the longitudinal cross section by using a recently developed Regge model. The results indicate that the pion form factor in this region is larger than previously assumed and is consistent with a monopole parametrization fitted to very low Q2 elastic data.

Published
2001
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32. Measurement of kinematic and nuclear dependence of R= sigma L/ sigma T in deep inelastic electron scattering.

Author

Dasu S, de Barbaro P, Bodek A, Harada H, Krasny MW, Lang K, Riordan EM, Andivahis L, Arnold R, Benton D, Bosted P, deChambrier G, Lung A, Rock SE, Szalata ZM, Walker RC, Filippone BW, Jourdan J, Milner R, McKeown R, Potterveld D, Para A, Dietrich F, Van Bibber K, Button-Shafer J, Debebe B, Hicks RS, Gearhart R, Whitlow LW, and Alster J

Published
1994
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33. Measurement of the difference in R= sigma L/ sigma T and of sigma A/ sigma D in deep-inelastic e-D, e-Fe, and e-Au scattering.

Author

Dasu S, de Barbaro P, Bodek A, Harada H, Krasny MW, Lang K, Riordan EM, Arnold R, Benton D, Bosted P, Clogher L, deChambrier G, Lung A, Rock SE, Szalata ZM, Walker RC, Filippone BW, Jourdan J, Milner R, McKeown R, Potterveld D, Para A, Dietrich F, Van Bibber K, Button-Shafer J, Debebe B, Hicks RS, Gearhart R, Whitlow LW, and Alster J

Published
1988
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