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1. Measurements of the separated longitudinal structure function FL from hydrogen and deuterium targets at low Q2

Author

Bogdan Wojtsekhowski, E. McGrath, T. Angelescu, D. H. Potterveld, B. L. Berman, B. Zihlmann, P. E. Reimer, E. R. Kinney, G. Chang, T. Horn, V. V. Frolov, C. Yan, J. Arrington, Y. Liang, G. M. Huber, A. Lung, G. S. Adams, Rolf Ent, James J. Kelly, J. Telfeyan, D. G. Meekins, T. Dodario, Curtis Smith, E. Segbefia, T. Ostapenko, H. E. Jackson, H. Mkrtchyan, Glen A. Warren, K. Hafidi, Donal Day, A. Uzzle, W. F. Vulcan, W. U. Boeglin, V. Tvaskis, E. J. Brash, N. S. Chant, M. E. Christy, G. Mbianda, I. Niculescu, P. Stoler, Joerg Reinhold, M. Ungaro, X. Jiang, O. K. Baker, Z. Papandreou, G. R. Smith, H. C. Fenker, M. M. Dalton, H. P. Blok, H. Breuer, A. Tvaskis, V. P. Kubarovsky, Cynthia Keppel, A. S. Biselli, J. Kuhn, Paul Gueye, S. A. Wood, A. Ahmidouch, J. A. Dunne, D. Abbott, Simon Henry Connell, S. Vidakovic, V. Tadevosyan, D. J. Mack, K. Garrow, R. J. Holt, Avraham Klein, Jim Napolitano, Stephen Avery, N. Benmouna, S. Danagoulian, S. E. Rock, N. El Khayari, E. Schulte, G. Niculescu, S. Malace, P. Bosted, F. R. Wesselmann, G. J. Lolos, J. Roche, M. Nozar, L. Todor, A. N. Villano, D. Mckee, T. Navasardyan, M. K. Jones, Dipanwita Dutta, R. Asaturyan, Pete Markowitz, D. Gaskell, W. Hinton, Ronald Gilman, Andrei Afanasev, K. Joo, and L. G. Tang

Subjects
Physics, Proton, 010308 nuclear & particles physics, Scattering, Momentum transfer, Parton, Deep inelastic scattering, 01 natural sciences, Molecular physics, Nuclear physics, Deuterium, 0103 physical sciences, Neutron, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Structure functions, as measured in lepton-nucleon scattering, have proven to be very useful in studying the partonic dynamics within the nucleon. However, it is experimentally difficult to separately determine the longitudinal and transverse structure functions, and consequently there are substantially less data available in particular for the longitudinal structure function. Here, we present separated structure functions for hydrogen and deuterium at low four-momentum transfer squared, Q2

Published
2018

2. Measurement of parton distributions of strange quarks in the nucleon from charged-kaon production in deep-inelastic scattering on the deuteron

Author

A. Reischl, W. Augustyniak, R. Perez-Benito, B. Maiheu, Alessandra Fantoni, D. Veretennikov, M. Negodaev, B. Hommez, G. Ciullo, Tetsuya Hasegawa, M. Hoek, E. De Sanctis, V. A. Gapienko, W.H.A. Hesselink, B. Zihlmann, Y. Naryshkin, P. E. Reimer, A. Kisselev, J. G. Rubin, A. Brull, B. Tchuiko, M. Kopytin, Cynthia Marie Hadjidakis, Y. Miyachi, A. Nass, G. Gapienko, I. Lehmann, D. Hasch, A. López Ruiz, Z. Akopov, A. Elalaoui-Moulay, Frank Ellinghaus, C. Shearer, B. Seitz, A. Hillenbrand, Y. Imazu, E. Nappi, Y. Van Haarlem, Michael Tytgat, E. R. Kinney, Y. Holler, A. Airapetian, U. Elschenbroich, S. Taroian, P. Lenisa, David Mahon, Y. Salomatin, B. Marianski, A. Trzcinski, P. B. van der Nat, J. Burns, Shan Wang, F. Stinzing, Andreas Schäfer, H. E. Jackson, V. G. Krivokhijine, A. Funel, B. Q. Ma, J. J. M. Steijger, Michael Düren, G. van der Steenhoven, A. Osborne, M. Stancari, P. Zupranski, C. Riedl, S. E. Rock, P. Di Nezza, V. Vikhrov, L. Rubacek, R. De Leo, A. Rostomyan, K. Rith, C. B. Van Hulse, A. Borissov, A. R. Reolon, A. Avetissian, M. Capiluppi, P. Liebing, A. Ivanilov, S. Belostotski, G. Rosner, H. Böttcher, V. Bryzgalov, J. Dreschler, L. De Nardo, W. Yu, F. Garibaldi, Morgan Murray, G. Iarygin, Zhenyu Ye, E. C. Aschenauer, G. Hill, K. P. Schüler, Y. X. Ye, P.F. Dalpiaz, J. Stewart, I. Vilardi, Andreas Mussgiller, A. Andrus, M. Diefenthaler, V. Gharibyan, P. Tait, L. A. Linden-Levy, W.-D. Nowak, T. A. Shibata, E. Avetissian, M. Demey, Nicola Bianchi, R.O. Avakian, H. Marukyan, C. Bonomo, E. Cisbani, V. A. Kozlov, D. Reggiani, G. Schnell, F. Giordano, S. Joosten, J. Streit, I. M. Gregor, H. Ye, A. Jgoun, Arne Vandenbroucke, Riccardo Fabbri, L. Manfré, Stephen V. Gliske, H. Guler, M. Varanda, L. Felawka, X. R. Lu, L. Lagamba, S. Yen, G. P. Capitani, Ralf Kaiser, E. Steffens, G. Gavrilov, L. Lapikás, M. Contalbrigo, Martin Raithel, I. Sanjiev, Naomi C R Makins, M. Ehrenfried, Andrey V. Izotov, C. A. Miller, D. Gabbert, Tsutomu Kobayashi, M. Statera, S. Frullani, N. Pickert, Dirk Ryckbosch, D. Zeiler, C. Vogel, V. A. Korotkov, G. Elbakian, S. Lu, Y. J. Mao, P. Kravchenko, Adel Terkulov, T. Keri, L. L. Pappalardo, Hasko Stenzel, Wouter Deconinck, Valeria Muccifora, V. Mexner, A. Nagaitsev, N. Akopov, S. Yaschenko, Vitaly Shutov, H. P. Blok, Wolfgang Lorenzon, Ivana Hristova, R. Lamb, (Astro)-Particles Physics, Photo Conversion Materials, and Student Lab and Education

Subjects
Quark, Particle physics, Strange quark, Nuclear and High Energy Physics, Nuclear Theory, FOS: Physical sciences, Parton, 01 natural sciences, NO, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), 13.60.-r, 13.88.+e, 14.20.Dh, 14.65.-q, 0103 physical sciences, ddc:530, SDG 14 - Life Below Water, 010306 general physics, Nuclear Experiment, Physics, 010308 nuclear & particles physics, Scattering, Deep inelastic scattering, Helicity, Strange matter, Physics and Astronomy, High Energy Physics::Experiment, Nucleon
Abstract

The momentum and helicity density distributions of the strange quark sea in the nucleon are obtained in leading order from charged-kaon production in deep-inelastic scattering on the deuteron. The distributions are extracted from spin-averaged K+/- multiplicities, and from K+/- and inclusive double-spin asymmetries for scattering of polarized positrons by a polarized deuterium target. The shape of the momentum distribution is softer than that of the average of the ubar and dbar quarks. In the region of measurement 0.02 < x < 0.6 and Q^2 > 1.0 GeV^2, the helicity distribution is zero within experimental uncertainties., 5 pages, 5 figures, 1 table; text slightly expanded, 10 references added

Published
2008
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3. Measurement of the Elastic Magnetic Form Factor of3Heat High Momentum Transfer

Author

M. C. Berisso, X. Jiang, P. Bosted, R. S. Hicks, T. Kobayashi, A. Cichocki, A. Hotta, R. A. Miskimen, W. Turchinetz, J. Shaw, I. Nakagawa, F. Casagrande, B. Asavapibhop, S. E. Rock, K. Burchesky, Tadaaki Tamae, Toshio Suda, S. Churchwell, K. Wang, and G. A. Peterson

Subjects
Physics, Transfer (group theory), Scattering, Magnetic form factor, Momentum transfer, General Physics and Astronomy, Electron, Atomic physics, High momentum, Electron scattering
Abstract

New electron scattering measurements have been made that extend data on the ${}^{3}\mathrm{He}$ elastic magnetic form factor up to ${Q}^{2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}42.6{\mathrm{fm}}^{\ensuremath{-}2}$. These new data test theoretical conjectures regarding non-nucleonic effects in the three-body system. The very small cross sections, as low as ${10}^{\ensuremath{-}40}{\mathrm{cm}}^{2}/\mathrm{sr}$, required the use of a high-pressure cryogenic gas target and a detector system with excellent background rejection capability. No existing theoretical calculation satisfactorily accounts for all the available data.

Published
2001

4. Measurements of R=σL/σT for 0.03<x<0.1 and fit to world data

Author

P. Raines, Ingo Sick, S.St. Lorant, D. Kawall, H. Borel, H. Tang, C. Y. Prescott, J. M. Bauer, H. R. Band, R. G. Arnold, F. S. Dietrich, L. M. Stuart, T. Maruyama, Ch. Hyde-Wright, D. Walz, J. L. White, J. S. McCarthy, P. E. Bosted, G. Court, T. Averett, Vincent Breton, P. Grenier, B. Raue, Kevin P. Coulter, S. Hoibraten, Pascal Steiner, R. Erbacher, F. Staley, D. Reyna, O. Rondon, P.L. Anthony, K. A. Griffioen, A. Feltham, E. W. Hughes, D. Crabb, J. Button-Shafer, R. Prepost, S. E. Rock, Timothy Chupp, A. Rijllart, J. Gomez, Timothy B. Smith, Y. Terrien, J. A. Dunne, L. C. Smith, K. Witte, T. L. Usher, W. Meyer, C. C. Young, J. Fellbaum, J. R. Johnson, D. Zimmermann, Avraham Klein, J. Morgenstern, M. Kuriki, Y. Roblin, Donal Day, Z. E. Meziani, F. Suekane, J. P. Chen, H. Dutz, R. C. Minehart, B. Zihlmann, Emil Frlez, B. Youngman, Koji Abe, R. Antonov, R. M. Lombard-Nelsen, H. Fonvieille, L. S. Rochester, R. A. Lindgren, G. G. Petratos, R. Gearhart, J. Marroncle, F.R. Wesselmann, John C. Mitchell, H. Yuta, G. H. Zapalac, R. Pitthan, J. Clendenin, T. J. Liu, Dinko Pocanic, S. E. Kuhn, Z. M. Szalata, T. Akagi, M. Spengos, X.K. Maruyama, D. Garvey, C. Comptour, and M. Daoudi

Subjects
Physics, Nuclear and High Energy Physics, Cross section.transverse, 010308 nuclear & particles physics, Scattering, chemistry.chemical_element, Electron, 01 natural sciences, Nuclear physics, Cross section (physics), chemistry, 0103 physical sciences, 010306 general physics, Carbon
Abstract

Measurements were made at SLAC of the cross section for scattering 29 GeV electrons from carbon at a laboratory angle of 4.5°, corresponding to 0.03

Published
1999

5. Measurement of the Proton and Deuteron Spin Structure Functiong1in the Resonance Region

Author

D. Crabb, A. Rijllart, J. P. Chen, F.R. Wesselmann, G. Court, John C. Mitchell, L. S. Rochester, R. Pitthan, Timothy B. Smith, H. Tang, D. Reyna, Ingo Sick, H. Borel, B. Zihlmann, Emil Frlez, M. Kuriki, L. C. Smith, J. Fellbaum, R. Antonov, Vincent Breton, O. Rondon, K. Witte, K. P. Coulter, R. M. Lombard-Nelsen, K. A. Griffioen, J. Clendenin, E. W. Hughes, J. R. Johnson, P.L. Anthony, C. Y. Prescott, A. Feltham, R. G. Arnold, P. Raines, T. J. Liu, Dinko Pocanic, F. S. Dietrich, R. Gearhart, S. E. Rock, S. E. Kuhn, J. Gomez, F. Suekane, James L. White, P. Grenier, R. Prepost, S.St. Lorant, G. H. Zapalac, W. Meyer, J. Button-Shafer, J. Marroncle, J. A. Dunne, R. C. Minehart, Koji Abe, Z. M. Szalata, C. C. Young, D. Walz, Avraham Klein, Ch. Hyde-Wright, H. Yuta, D. Kawall, P. E. Bosted, D. Garvey, H. Fonvieille, B. Raue, H. Dutz, R. A. Lindgren, Timothy Chupp, S. Hoibraten, Pascal Steiner, F. Staley, B. Youngman, G. G. Petratos, T. Averett, R. Erbacher, Z. E. Meziani, J. Morgenstern, X.K. Maruyama, Donal Day, C. Comptour, M. Daoudi, J. M. Bauer, H. R. Band, Y. Roblin, L. M. Stuart, T. Maruyama, T. L. Usher, D. Zimmermann, Y. Terrien, J. S. McCarthy, T. Akagi, and M. Spengos

Subjects
Physics, Nuclear physics, Proton, Scattering, General Physics and Astronomy, Resonance, Electron, Atomic physics, Inelastic scattering, Spin structure, Nucleon, Spin-½
Abstract

We have measured the proton and deuteron spin structure functions g[sup p][sub 1] and g[sup d][sub 1] in the region of the nucleon resonances for W2 < 5GeV2 and Q2(similar, equals)0.5 and Q2(similar, equals)1.2GeV2 by inelastically scattering 9.7 GeV polarized electrons off polarized 15NH3 and 15ND3 targets. We observe significant structure in g[sup p][sub 1] in the resonance region. We have used the present results, together with the deep-inelastic data at higher W2, to extract Gamma (Q2)(equivalent)01 g1(x,Q2)dx. This is the first information on the low-Q2 evolution of Gamma toward the Gerasimov-Drell-Hearn limit at Q2 = 0.

Published
1997

6. Deep inelastic scattering of polarized electrons by polarizedHe3and the study of the neutron spin structure

Author

W. Meyer, Sayed Rokni, Timothy Chupp, Y. Roblin, J. Morgenstern, C. C. Young, R. Prepost, H. Borel, E. W. Hughes, Z. M. Szalata, S. E. Rock, Timothy B. Smith, R. G. Arnold, H. Fonvieille, M. Woods, H. R. Band, F. S. Dietrich, P. E. Bosted, J. Fellbaum, F. Staley, H. Middleton, M. Spengos, Y. Terrien, Alan K. Thompson, L. M. Stuart, R. Erbacher, J. A. Dunne, T. Maruyama, J. Xu, Z. E. Meziani, Gilbert Shapiro, J. R. Johnson, N. R. Newbury, D. Kawall, G. G. Petratos, R. Holmes, G. H. Zapalac, J. Marroncle, P.L. Anthony, C. E. Keppel, James L. White, Vincent Breton, S. E. Kuhn, Gordon D. Cates, R. Pitthan, Paul A Souder, R. M. Lombard-Nelsen, and R. A. Gearhart

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Proton, High density, Neutron, Electron, Spin structure, Nucleon, Deep inelastic scattering
Abstract

The neutron longitudinal and transverse asymmetries ${A}_{1}^{n}$ and ${A}_{2}^{n}$ have been extracted from deep inelastic scattering of polarized electrons by a polarized $^{3}\mathrm{He}$ target at incident energies of 19.42, 22.66, and 25.51 GeV. The measurement allows for the determination of the neutron spin structure functions ${g}_{1}^{n}(x, {Q}^{2})$ and ${g}_{2}^{n}(x, {Q}^{2})$ over the range $0.03lxl0.6$ at an average ${Q}^{2}$ of 2 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$. The data are used for the evaluation of the Ellis-Jaffe and Bjorken sum rules. The neutron spin structure function ${g}_{1}^{n}(x, {Q}^{2})$ is small and negative within the range of our measurement, yielding an integral $\ensuremath{\int}{0.03}^{0.6}{g}_{1}^{n}(x)\mathrm{dx}=\ensuremath{-}0.028\ifmmode\pm\else\textpm\fi{}0.006 (\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.006 (\mathrm{syst})$. Assuming Regge behavior at low $x$, we extract ${\ensuremath{\Gamma}}_{1}^{n}=\ensuremath{\int}{0}^{1}{g}_{1}^{n}(x)\mathrm{dx}=\ensuremath{-}0.031\ifmmode\pm\else\textpm\fi{}0.006 (\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.009 (\mathrm{syst})$. Combined with previous proton integral results from SLAC experiment E143, we find ${\ensuremath{\Gamma}}_{1}^{p}\ensuremath{-}{\ensuremath{\Gamma}}_{1}^{n}=0.160\ifmmode\pm\else\textpm\fi{}0.015$ in agreement with the Bjorken sum rule prediction ${\ensuremath{\Gamma}}_{1}^{p}\ensuremath{-}{\ensuremath{\Gamma}}_{1}^{n}=0.176\ifmmode\pm\else\textpm\fi{}0.008$ at a ${Q}^{2}$ value of 3 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$ evaluated using ${\ensuremath{\alpha}}_{s}=0.32\ifmmode\pm\else\textpm\fi{}0.05$.

Published
1996

7. Inclusive electron scattering from nuclei atx≃1

Author

J. Arrington, H. J. Bulten, Haiyan Gao, H. E. Jackson, P. L. Anthony, D. H. Potterveld, B. Mueller, L. H. Tao, Kisoo Lee, B. Zeidman, P. E. Bosted, R. Gearhart, S. E. Kuhn, C. E. Jones, J. O. Hansen, K. P. Coulter, Ross Milner, J. L. White, E. R. Kinney, J. E. Belz, M. Spengos, B. W. Filippone, D. F. Geesaman, G. G. Petratos, R. G. Arnold, Z. M. Szalata, Michael Chapman, S. E. Rock, F. S. Dietrich, R. Ent, van den J.F.J. Brand, R. D. McKeown, D. Winter, E. J. Beise, D. J. Margaziotis, C. E. Keppel, R. J. Holt, Naomi C R Makins, Thomas O'Neill, A. Lung, M. Epstein, V. Papavassiliou, Jenny Nelson, Wolfgang Lorenzon, van K. Bibber, and J. Napolitano

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Scattering, Momentum transfer, Duality (optimization), Scattering length, Electron, 01 natural sciences, Nuclear physics, 0103 physical sciences, Atomic physics, 010306 general physics, Nucleon, Electron scattering, Scaling
Abstract

The inclusive A(e,e′) cross section for x≃1 was measured on ^2H, C, Fe, and Au for momentum transfers Q^2 from 1 to 6.8 (GeV/c)^2. The scaling behavior of the data was examined in the region of transition from y scaling to x scaling. Throughout this transitional region, the data exhibit ξ scaling, reminiscent of the Bloom-Gilman duality seen in free nucleon scattering.

Published
1996

8. Measurements of the Proton and Deuteron Spin Structure Functiong2and AsymmetryA2

Author

Y. Terrien, L.S. Rochester, T. L. Usher, J. Morgenstern, Donal Day, J. M. Bauer, R. A. Lindgren, D. Zimmermann, R. Prepost, K. A. Griffioen, H. R. Band, R. A. Gearhart, H. Borel, John C. Mitchell, C. Y. Prescott, T. Akagi, Y. Roblin, J. Gomez, H. Fonvieille, P. Grenier, E. W. Hughes, J. Button-Shafer, G. H. Zapalac, R. G. Arnold, J. Marroncle, D. Kawall, Jian-Ping Chen, T. Averett, W. Meyer, D. Walz, P. Raines, F. S. Dietrich, H. Yuta, C. E. Hyde-Wright, Timothy B. Smith, R. Pitthan, L. M. Stuart, K. Witte, P. E. Bosted, T. Maruyama, P.L. Anthony, Avraham Klein, Kevin P. Coulter, James L. White, J. Fellbaum, S.St. Lorant, D. Reyna, D. Garvey, B. Zihlmann, Emil Frlez, F. Staley, C. C. Young, T. J. Liu, M. Spengos, A. Rijllart, B. Raue, Z. M. Szalata, S. Hoibraten, R. Antonov, M. Kuriki, H. Dutz, J. A. Dunne, R. M. Lombard-Nelsen, Dinko Pocanic, K. Abe, Pascal Steiner, B. Youngman, X.K. Maruyama, L. C. Smith, O. Rondon, J. Clendenin, R. Erbacher, Z. E. Meziani, S. E. Kuhn, S. E. Rock, C. Comptour, G. G. Petratos, M. Daoudi, Ingo Sick, Timothy Chupp, J.R. Johnson, Vincent Breton, R. C. Minehart, A. Feltham, G.R. Court, D. G. Crabb, H. Tang, J. S. McCarthy, and F. Suekane

Subjects
Physics, Matrix (mathematics), Deuterium, Proton, Scattering, media_common.quotation_subject, General Physics and Astronomy, Electron, Atomic physics, Spin structure, Asymmetry, media_common, Spin-½
Abstract

We have measured proton and deuteron virtual photon-nucleon asymmetries A{sup p}{sub 2} and A{sup d}{sub 2} and structure functions g{sup p}{sub 2} and g{sup d}{sub 2} over the range 0.03 < x < 0.8 and 1.3 < Q{sup 2} < 10 (GeV/c){sup 2} by inelastically scattering polarized electrons off polarized ammonia targets. Results for A{sub 2} are significantly smaller than the positivity limit (sqrt)R for both targets. Within experimental precision the g{sub 2} data are well described by the twist-2 contribution, g{sup ww}{sub 2}. Twist-3 matrix elements have been extracted and are compared to theoretical predictions.

Published
1996

9. Measurements of the Q2-dependence of the proton and deuteron spin structure functions g1 and g1

Author

A. Rijllart, J. Marroncle, Z. M. Szalata, J. Clendenin, T. Akagi, P. Raines, H. Dutz, T. J. Liu, Dinko Pocanic, H. R. Band, M. Kuriki, J. P. Chen, John C. Mitchell, S. E. Kuhn, B. Youngman, R. Prepost, S.St. Lorant, D. Walz, G. Court, Ingo Sick, Timothy B. Smith, J. Gomez, X.K. Maruyama, D. Kawall, K. Witte, L. M. Stuart, T. Maruyama, P. E. Bosted, P.L. Anthony, J. Fellbaum, C. Comptour, M. Daoudi, C. E. Hyde-Wright, R. Pitthan, D. Garvey, C. Y. Prescott, W. Meyer, Avraham Klein, R. A. Lindgren, G. G. Petratos, M. Spengos, F. Staley, L.S. Rochester, C. C. Young, T. L. Usher, B. Raue, S. Hoibraten, R. C. Minehart, D. Zimmermann, Pascal Steiner, H. Yuta, P. Grenier, K. A. Griffioen, Timothy Chupp, L. C. Smith, F. Suekane, J. Morgenstern, J. R. Johnson, G. H. Zapalac, Donal Day, Y. Roblin, D. G. Crabb, H. Tang, J. Button-Shafer, Koji Abe, J. A. Dunne, H. Fonvieille, H. Borel, J. S. McCarthy, F. S. Dietrich, T. Averett, R. G. Arnold, R. Erbacher, Z. E. Meziani, D. Reyna, R. A. Gearhart, A. Feltham, E. W. Hughes, J. L. White, J. M. Bauer, Vincent Breton, Kevin P. Coulter, O. Rondon, S. E. Rock, Y. Terrien, B. Zihlmann, Emil Frlez, R. Antonov, and R. M. Lombard-Nelsen

Subjects
Nuclear physics, Physics, High Energy Physics - Experiment (hep-ex), Nuclear and High Energy Physics, Deuterium, Proton, FOS: Physical sciences, Spin structure, High Energy Physics - Experiment
Abstract

The ratio g1/F1 has been measured over the range 0.031 (GeV/c)2. A trend is observed for g1/F1 to decrease at lower Q2. Fits to world data with and without a possible Q2-dependence in g1/F1 are in agreement with the Bjorken sum rule, but Delta_q is substantially less than the quark-parton model expectation., Comment: 16 pages, format is postscript file, gzip-ed, uuencode-ed

Published
1995

10. Evidence For Virtual Compton-Scattering From The Proton

Author

B. W. Filippone, Jenny Nelson, Kisoo Lee, Haiyan Gao, D. H. Potterveld, D. F. Geesaman, E. R. Kinney, H. E. Jackson, B. Zeidman, S. E. Rock, R. D. McKeown, K. van Bibber, B. Mueller, Michael Chapman, M. B. Epstein, K. P. Coulter, R. A. Gearhart, Jim Napolitano, Wolfgang Lorenzon, D. J. Margaziotis, J. Arrington, E. J. Beise, H. J. Bulten, P.L. Anthony, J.-O. Hansen, F. S. Dietrich, S. E. Kuhn, J. F. J. van den Brand, P. E. Bosted, G. G. Petratos, J. E. Belz, Thomas O'Neill, L. H. Tao, M. Spengos, Rolf Ent, V. Papavassiliou, Z. M. Szalata, A. Lung, D. A. Wasson, R. G. Arnold, C. E. Jones, C. E. Keppel, Ross Milner, James L. White, R. J. Holt, and Naomi C R Makins

Subjects
Physics, Photon, Proton, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Compton scattering, Electron, Compton wavelength, MAGNETIC FORM-FACTORS, Inelastic scattering, Q(2)=1.75, Linear particle accelerator, Nuclear physics, (GEV/C)(2), Physics::Accelerator Physics, Nucleon, Nuclear Experiment
Abstract

In virtual Compton scattering an electron is scattered off a nucleon such that the nucleon emits a photon. We show that these events can be selected experimentally, and present the first evidence for virtual Compton scattering from the proton in data obtained at the Stanford Linear Accelerator Center. The angular and energy dependence of the data is well described by a calculation that includes the coherent sum of electron and proton radiation.

Published
1995

11. Precision Measurement of the Deuteron Spin Structure Functiong1d

Author

H. Dutz, B. Youngman, John C. Mitchell, J. M. Bauer, G. H. Zapalac, P.L. Anthony, J. Marroncle, F. Suekane, D. Crabb, A. Rijllart, Ingo Sick, P. Raines, Koji Abe, P. Grenier, L. S. Rochester, R. Pitthan, Y. Roblin, C. Y. Prescott, O. Rondon, K. P. Coulter, Ch. Hyde-Wright, W. Meyer, F. S. Dietrich, Jian-Ping Chen, R. C. Minehart, S. E. Rock, J. Gomez, H. Fonvieille, M. Kuriki, X.K. Maruyama, J. Button-Shafer, F. Staley, H. Borel, T. Averett, R. Prepost, Z. M. Szalata, Timothy B. Smith, S.St. Lorant, R. Erbacher, Z. E. Meziani, D. Walz, D. Kawall, Timothy Chupp, P. E. Bosted, R. G. Arnold, C. Comptour, T. L. Usher, H. Yuta, K. Witte, G. Court, Y. Terrien, M. Daoudi, D. Garvey, D. Zimmermann, H. Tang, M. Spengos, B. Raue, J. Fellbaum, R. A. Lindgren, G. G. Petratos, J. Morgenstern, S. Hoibraten, Pascal Steiner, T. J. Liu, Dinko Pocanic, Donal Day, L. C. Smith, S. E. Kuhn, J. Clendenin, T. Akagi, J. A. Dunne, J. R. Johnson, J. S. McCarthy, Avraham Klein, D. Reyna, B. Zihlmann, Emil Frlez, J. L. White, R. Antonov, R. M. Lombard-Nelsen, Vincent Breton, K. A. Griffioen, A. Feltham, E. W. Hughes, R. Gearhart, C. C. Young, L. M. Stuart, T. Maruyama, and H. R. Band

Subjects
Physics, Nuclear physics, General Physics and Astronomy, Library science, Christian ministry
Abstract

This work was supported by Department of Energy Contracts No. DE-AC05-84ER40150 (CEBAF), No. W-2795-Eng-48 (LLNL), No. DE-AC0376SF00515 (SLAC), No. DE-FG03-88ER40439 (Stanford), No. DE-FG05-88ER40390 and No. DEFG05-86ER4026 (Virginia), and No. DE-AC02-76ER00881 (Wisconsin); by National Science Foundation Grants No. 9114958 (American), No. 9307710 (Massachusetts), No. 9217979 (Michigan), No. 9104975 (ODU) and No. 9118137 (U. Penn.); by the Schweizersche Nationalfonds (Basel); by the Commonwealth of Virginia (Virginia); by the Centre NAtional de la Recherche Scientifique and the Commissariat a l'Energie Atomique (French groups); and by the Japanese Ministry of Education, Science and Culture (Tohoku).

Published
1995

12. Precision Measurement of the Proton Spin Structure Functiong1p

Author

T. Akagi, O. Rondon, H. Yuta, K. P. Coulter, K. Witte, J. Marroncle, S. E. Rock, R. Gearhart, D. Crabb, A. Rijllart, J. Gomez, C. C. Young, J. Clendenin, L. C. Smith, Y. Roblin, X.K. Maruyama, G. H. Zapalac, L. M. Stuart, K. A. Griffioen, John C. Mitchell, P. Grenier, R. C. Minehart, T. Maruyama, H. Borel, J. R. Johnson, Timothy B. Smith, Koji Abe, C. Comptour, M. Daoudi, T. L. Usher, C. Y. Prescott, Y. Terrien, F. S. Dietrich, J. A. Dunne, H. R. Band, P. Raines, A. Feltham, E. W. Hughes, Ch. Hyde-Wright, G.R. Court, M. Kuriki, H. Dutz, Avraham Klein, H. Fonvieille, Donal Day, J. Fellbaum, D. Zimmermann, J. P. Chen, T. J. Liu, Dinko Pocanic, J. L. White, J. Button-Shafer, T. Averett, S. E. Kuhn, Vincent Breton, R. Erbacher, Z. E. Meziani, J. M. Bauer, L. S. Rochester, S.St. Lorant, R. Pitthan, R. A. Lindgren, G. G. Petratos, D. Reyna, D. Kawall, F. Staley, Z. M. Szalata, R. Prepost, D. Walz, P. E. Bosted, Ingo Sick, D. Garvey, F. Suekane, J. S. McCarthy, R. G. Arnold, M. Spengos, P.L. Anthony, B. Raue, S. Hoibraten, Pascal Steiner, W. Meyer, Timothy Chupp, B. Youngman, J. Morgenstern, B. Zihlmann, Emil Frlez, R. Antonov, R. M. Lombard-Nelsen, and H. Tang

Subjects
Combinatorics, Physics, Nuclear magnetic resonance, Particle properties, Hydrogen compounds, Proton spin crisis, Structure function, General Physics and Astronomy
Abstract

We have measured the ratio [ital g][sup [ital p]][sub 1]/[ital F][sup [ital p]][sub 1] over the range 0.029[lt][ital x][lt]0.8 and 1.3[lt][ital Q][sup 2][lt]10 (GeV/[ital c])[sup 2] using deep-inelastic scattering of polarized electrons from polarized ammonia. An evaluation of the integral [integral][ital g][sup [ital p]][sub 1]([ital x],[ital Q][sup 2])[ital dx] at fixed [ital Q][sup 2]=3 (GeV/[ital c])[sup 2] yields 0.127[plus minus]0.004(stat)[plus minus]0.010(syst), in agreement with previous experiments, but well below the Ellis-Jaffe sum rule prediction of 0.160[plus minus]0.006. In the quark-parton model, this implies [Delta][ital q]=0.27[plus minus]0.10.

Published
1995

13. Measurements of the proton elastic form factors for1≤Q2≤3(GeV/c)2at SLAC

Author

E. M. Riordan, B. Debebe, A. Para, M. W. Krasny, B. W. Filippone, R. G. Arnold, R. S. Hicks, R. Gearhart, Sridhara Dasu, J. Alster, F. Dietrich, L.W. Whitlow, G. deChambrier, J. Jourdan, J. Button-Shafer, D. Benton, P. de Barbaro, Karol Lang, L. Andivahis, R. D. McKeown, K. van Bibber, P. E. Bosted, D. H. Potterveld, A. Bodek, Ross Milner, S. E. Rock, Z. M. Szalata, A. Lung, H. Harada, and R. C. Walker

Subjects
Physics, Combinatorics, Scattering cross-section, Particle physics, Particle properties, Proton, Particle model, Theoretical models
Abstract

We report measurements of the proton form factors [ital G][sub [ital E]][sup [ital p]] and [ital G][sub [ital M]][sup [ital p]] extracted from elastic scattering in the range 1[le][ital Q][sup 2][le]3 (GeV/[ital c])[sup 2] with total uncertainties [lt] 15% in [ital G][sub [ital E]][sup [ital p]] and [lt] 3% in [ital G][sub [ital M]][sup [ital p]]. Comparisons are made to theoretical models, including those based on perturbative QCD, vector-meson dominance, QCD sum rules, and diquark constituents in the proton. The results for [ital G][sub [ital E]][sup [ital p]] are somewhat larger than indicated by most theoretical parametrizations, and the ratios of the Pauli and Dirac form factors [ital Q][sup 2]([ital F][sub 2][sup [ital p]]/[ital F][sub 1][sup [ital p]]) are lower in value and demonstrate a weaker [ital Q][sup 2] dependence than those predictions. A global extraction of the elastic form factors from several experiments in the range 0.1 [lt] [ital Q][sup 2] [lt] 10 (GeV/[ital c])[sup 2] is also presented.

Published
1994

14. Measurement of kinematic and nuclear dependence ofR=σLσTin deep inelastic electron scattering

Author

M. W. Krasny, P. E. Bosted, B. W. Filippone, B. Debebe, D. Benton, J. Button-Shafer, A. Lung, R. S. Hicks, A. Bodek, G. deChambrier, S. E. Rock, R. A. Gearhart, F. S. Dietrich, Ross Milner, K. van Bibber, Sridhara Dasu, H. Harada, R. G. Arnold, J. Alster, D. H. Potterveld, R. D. McKeown, L.W. Whitlow, R. C. Walker, J. Jourdan, L. Andivahis, A. Para, Z. M. Szalata, P. de Barbaro, Karol Lang, and E. M. Riordan

Subjects
Nuclear physics, Physics, Quantum chromodynamics, Particle physics, Scattering, EMC effect, Elementary particle, Twist, Inelastic scattering, Nucleon, Deep inelastic scattering
Abstract

We report results on a precision measurement of the ratio R=σ_L/σ_T in deep inelastic electron-nucleon scattering in the kinematic range 0.2≤x≤0.5 and 1≤Q^2≤10 (GeV/c)^2. Our results show, for the first time, a clear falloff of R with increasing Q^2. Our R results are in agreement with QCD predictions only when corrections for target mass effects and some additional higher twist effects are included. At small x, the data on R favor structure functions with a large gluon contribution. We also report results on the differences R_A-R_D and the cross section ratio σ^A/σ^D between Fe and Au nuclei and the deuteron. Our results for R_A-R_D are consistent with zero for all x, Q^2 indicating that possible contributions to R from nuclear higher twist effects and spin-0 constituents in nuclei are not different from those in nucleons. The ratios σ^A/σ^D from all recent experiments, at all x, Q^2 values, are now in agreement.

Published
1994

15. Momentum transfer dependence of nuclear transparency from the quasielasticC12(e,e’p) reaction

Author

L. H. Tao, B. Mueller, C. E. Keppel, van Bibber K, B. W. Filippone, C. E. Jones, D. H. Potterveld, R. J. Holt, Naomi C R Makins, R. A. Gearhart, R. Ent, B. Zeidman, D. J. Margaziotis, M. B. Epstein, K. P. Coulter, Papavassiliou, S. E. Rock, Z. M. Szalata, Thomas O'Neill, H. J. Bulten, E. Belz, Haiyan Gao, J. O. Hansen, S. E. Kuhn, J. Nelson, Ross Milner, J. Arrington, H. E. Jackson, Michael Chapman, E. J. Beise, P. E. Bosted, M. Spengos, van den Brand Jf, Patratos Gg, J. L. White, E. R. Kinney, A. Lung, P. L. Anthony, R. G. Arnold, R. D. McKeown, Wolfgang Lorenzon, Kisoo Lee, D. F. Geesaman, J. Napolitano, and F. S. Dietrich

Subjects
Nuclear reaction, Physics, Scattering, Nuclear Theory, Momentum transfer, Hadron, General Physics and Astronomy, Nuclear physics, Baryon, Nuclear transparency, Atomic physics, Nuclear Experiment, Nucleon, Lepton
Abstract

The cross section for quasielastic ^(12)C(e,e’p) scattering has been measured at momentum transfer Q^2=1, 3, 5, and 6.8 (GeV/c)^2. The results are consistent with scattering from a single nucleon as the dominant process. The nuclear transparency is obtained and compared with theoretical calculations that incorporate color transparency effects. No significant rise of the transparency with Q^2 is observed.

Published
1994

16. Semi-Inclusive Charged-Pion Electroproduction off Protons and Deuterons: Cross Sections, Ratios and Access to the Quark-Parton Model at Low Energies

Author

N. Kalantarians, C. Xu, L. Yuan, T. Horn, A. Ahmidouch, Y. Cui, Dipangkar Dutta, P. E. Reimer, G. S. Adams, E. Schulte, W. Hinton, R. J. Holt, T. Navasardyan, R. Ent, S. A. Wood, Curtis Smith, Y. Liang, S. Danagoulian, M. Wang, H. Mkrtchyan, Simon Henry Connell, K. Hafidi, P. Bosted, Y. Li, E. Segbefia, S. E. Rock, A. N. Villano, A. Asaturyan, Bogdan Wojtsekhowski, John Arrington, S. Vidakovic, V. Tadevosyan, Glen A. Warren, C. Bertoncini, M. M. Dalton, James J. Kelly, I. Niculescu, M. E. Christy, O. K. Baker, P. McKee, X. Zheng, T. Angelescu, G. Niculescu, N. Benmouna, D. J. Mack, L. Gan, J. Roche, J. A. Dunne, X. Jiang, D. G. Meekins, A. Mkrtchyan, V. P. Kubarovsky, J. Reinhold, S. Malace, H. Breuer, W. U. Boeglin, Donal Day, E. V. Hungerford, A. K. Opper, E. McGrath, C. E. Keppel, F. R. Wesselmann, Geoffrey Smith, R. Asaturyan, N. El Khayari, Pete Markowitz, V. V. Frolov, G. M. Huber, M. Ungaro, P. Stoler, B. Moziak, H. P. Blok, K. Joo, A. Uzzle, H. C. Fenker, L. G. Tang, T. Ostapenko, W. F. Vulcan, M. K. Jones, and D. Gaskell

Subjects
Physics, Quark, Nuclear and High Energy Physics, Particle physics, Proton, 010308 nuclear & particles physics, Scattering, High Energy Physics::Phenomenology, Nuclear Theory, FOS: Physical sciences, Parton, Deep inelastic scattering, 01 natural sciences, Nuclear physics, Pion, 0103 physical sciences, Invariant mass, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), 010306 general physics, Nucleon, Nuclear Experiment
Abstract

A large set of cross sections for semi-inclusive electroproduction of charged pions ($��^\pm$) from both proton and deuteron targets was measured. The data are in the deep-inelastic scattering region with invariant mass squared $W^2$ > 4 GeV$^2$ and range in four-momentum transfer squared $2 < Q^2 < 4$ (GeV/c)$^2$, and cover a range in the Bjorken scaling variable 0.2 < x < 0.6. The fractional energy of the pions spans a range 0.3 < z < 1, with small transverse momenta with respect to the virtual-photon direction, $P_t^2 < 0.2$ (GeV/c)$^2$. The invariant mass that goes undetected, $M_x$ or W', is in the nucleon resonance region, W' < 2 GeV. The new data conclusively show the onset of quark-hadron duality in this process, and the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark --> pion production mechanisms. The x, z and $P_t^2$ dependences of several ratios (the ratios of favored-unfavored fragmentation functions, charged pion ratios, deuteron-hydrogen and aluminum-deuteron ratios for $��^+$ and $��^-$) have been studied. The ratios are found to be in good agreement with expectations based upon a high-energy quark-parton model description. We find the azimuthal dependences to be small, as compared to exclusive pion electroproduction, and consistent with theoretical expectations based on tree-level factorization in terms of transverse-momentum-dependent parton distribution and fragmentation functions. In the context of a simple model, the initial transverse momenta of $d$ quarks are found to be slightly smaller than for $u$ quarks, while the transverse momentum width of the favored fragmentation function is about the same as for the unfavored one, and both fragmentation widths are larger than the quark widths.

Published
2011

17. Determination of the neutron spin structure function

Author

H. Fonvieille, E. W. Hughes, Y. Terrien, Sayed Rokni, Thomas E. Smith, P. E. Bosted, J. Xu, H. Borel, F. S. Dietrich, R. A. Gearhart, J. Fellbaum, P.L. Anthony, S. E. Rock, H. Middleton, M. Spengos, F. Staley, Nathan R. Newbury, R. G. Arnold, Vincent Breton, H. R. Band, Gordon D. Cates, R. Prepost, S. E. Kuhn, R. Erbacher, Gilbert Shapiro, J. A. Dunne, James L. White, M. Woods, Z. E. Meziani, G. G. Petratos, W. Meyer, Timothy Chupp, R. Holmes, G. H. Zapalac, J. Marroncle, J.R. Johnson, Z. M. Szalata, Paul Souder, C. E. Keppel, C. C. Young, R. Pitthan, R. M. Lombard-Nelsen, L. M. Stuart, D. Kawall, J. Morgenstern, T. Maruyama, Alan K. Thompson, Y. Roblin, Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), E142, and Hughes V.W. Cavata C.

Subjects
Physics, Nuclear reaction, Particle physics, Proton, 010308 nuclear & particles physics, Hadron, General Physics and Astronomy, Elementary particle, Inelastic scattering, 01 natural sciences, 7. Clean energy, 0103 physical sciences, Proton spin crisis, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Sum rule in quantum mechanics, 010306 general physics, Nucleon
Abstract

The authors report the results of the experiment E142 which measured the spin dependent structure function of the neutron, g{sub 1}{sup n}(x, Q{sup 2}). The experiment was carried out at the Stanford Linear Accelerator Center by measuring an asymmetry in the deep inelastic scattering of polarized electrons from a polarized {sup 3}He target, at electron energies from 19 to 26 GeV. The structure function was determined over the kinematic range 0.03 < BJorken x < 0.6 and 1.0 < Q{sup 2} < 5.5 (GeV/c){sup 2}. An evaluation of the integral {integral}{sub 0}{sup 1} g{sub 1}{sup n}(x,Q{sup 2})dx at fixed Q{sup 2} = 2 (GeV/c){sup 2} yields the final result {Lambda}{sub 1}{sup n} = -0.032 {+-} 0.006 (stat.) {+-} 0.009 (syst.). This result, when combined with the integral of the proton spin structure function measured in other experiments, confirms the fundamental Bjorken sum rule with O({alpha}{sub s}{sup 3}) corrections to within one standard deviation. This is a major success for perturbative Quantum Chromodynamics. Some ancillary results include the findings that the Ellis-Jaffe sum rule for the neutron is violated at the 2 {sigma} level, and that the total contribution of the quarks to the helicity of the nucleon is 0.36 {+-}more » 0.10. The strange sea polarization is estimated to be small and negative, {Delta}s = -0.07 {+-} 0.04.« less

Published
1993

18. Measurements of the electric and magnetic form factors of the neutron fromQ2=1.75 to 4.00 (GeV/c)2

Author

A. Lung, L. M. Stuart, P. E. Bosted, L. Andivahis, J. Alster, R. G. Arnold, C. C. Chang, F. S. Dietrich, W. R. Dodge, R. Gearhart, J. Gomez, K. A. Griffioen, R. S. Hicks, C. E. Hyde-Wright, C. Keppel, S. E. Kuhn, J. Lichtenstadt, R. A. Miskimen, G. A. Peterson, G. G. Petratos, S. E. Rock, S. H. Rokni, W. K. Sakumoto, M. Spengos, K. Swartz, Z. Szalata, and L. H. Tao

Subjects
General Physics and Astronomy
Published
1993

19. Measurements of the electric and magnetic form factors of the proton fromQ2=1.75 to 8.83 (GeV/c)2

Author

P. E. Bosted, Sayed Rokni, J. Alster, M. Spengos, L. M. Stuart, K. A. Griffioen, L. Andivahis, R. G. Arnold, L. H. Tao, C. E. Hyde-Wright, Sakumoto Wk, W. R. Dodge, J. Lichtenstadt, A. Lung, Z. M. Szalata, F. S. Dietrich, S. E. Rock, J. Gomez, G. G. Petratos, R. S. Hicks, R. A. Gearhart, G. A. Peterson, C. C. Chang, K. Swartz, S. E. Kuhn, R. A. Miskimen, and C. E. Keppel

Subjects
Scattering cross-section, Physics, Particle physics, Particle properties, Proton, Particle model, Quark model, Hadron, Form factor (quantum field theory), General Physics and Astronomy, Elementary particle, Vector meson dominance, Baryon, Combinatorics, Crystallography, Neutron, Nucleon
Abstract

The proton elastic form factors ${\mathit{G}}_{\mathit{E}\mathit{p}}$(${\mathit{Q}}^{2}$) and ${\mathit{G}}_{\mathit{M}\mathit{p}}$(${\mathit{Q}}^{2}$) have been extracted for ${\mathit{Q}}^{2}$=1.75 to 8.83 (GeV/c${)}^{2}$ via a Rosenbluth separation to ep elastic cross section measurements in the angular range 13\ifmmode^\circ\else\textdegree\fi{}\ensuremath{\le}\ensuremath{\theta}\ensuremath{\le}90\ifmmode^\circ\else\textdegree\fi{}. The ${\mathit{Q}}^{2}$ range covered more than doubles that of the existing data. For ${\mathit{Q}}^{2}$4 (GeV/c${)}^{2}$, where the data overlap with previous measurements, the total uncertainties have been reduced to 14% in ${\mathit{G}}_{\mathit{E}\mathit{p}}$ and 1.5% in ${\mathit{G}}_{\mathit{M}\mathit{p}}$. Results for ${\mathit{G}}_{\mathit{E}\mathit{p}}$(${\mathit{Q}}^{2}$) are consistent with the dipole fit ${\mathit{G}}_{\mathit{D}}$(${\mathit{Q}}^{2}$)=(1+${\mathit{Q}}^{2}$/0.71${)}^{\mathrm{\ensuremath{-}}2}$, while those for ${\mathit{G}}_{\mathit{M}\mathit{p}}$(${\mathit{Q}}^{2}$)/${\mathrm{\ensuremath{\mu}}}_{\mathit{p}}$${\mathit{G}}_{\mathit{D}}$(${\mathit{Q}}^{2}$) decrease smoothly from 1.05 to 0.92. Deviations from form factor scaling are observed up to 20%. The ratio ${\mathit{Q}}^{2}$${\mathit{F}}_{2}$/${\mathit{F}}_{1}$ is observed to approach a constant value for ${\mathit{Q}}^{2}$g3 (GeV/c${)}^{2}$. Comparisons are made to vector meson dominance, dimensional scaling, QCD sum rule, diquark, and constituent quark models, none of which fully characterize all the new data.

Published
1992

20. Electroproduction ofηmesons in theS11(1535)resonance region at high momentum transfer

Author

R. J. Holt, H. Mkrtchyan, N. El Khayari, E. Schulte, S. A. Wood, Simon Henry Connell, M. K. Jones, S. E. Rock, Y. Li, M. E. Christy, P. Bosted, Bogdan Wojtsekhowski, N. Kalantarians, L. Gan, P. E. Reimer, C. Xu, E. V. Hungerford, T. Horn, A. N. Villano, C. Bertoncini, L. Yuan, H. Breuer, M. M. Dalton, V. V. Frolov, T. Navasardyan, A. K. Opper, F. R. Wesselmann, A. Uzzle, G. M. Huber, Y. Liang, M. Wang, R. Asaturyan, D. Gaskell, Pete Markowitz, P. Stoler, N. Benmouna, D. G. Meekins, Curtis Smith, Y. Cui, G. S. Adams, A. Ahmidouch, O. K. Baker, Rolf Ent, K. Hafidi, V. Tvaskis, B. Moziak, W. U. Boeglin, S. Vidakovic, V. Tadevosyan, James J. Kelly, T. Dodario, G. Niculescu, W. Hinton, X. Jiang, T. Ostapenko, X. Zheng, W. F. Vulcan, Glen A. Warren, V. P. Kubarovsky, H. C. Fenker, E. Segbefia, Joerg Reinhold, P. McKee, Hongbo Zhu, Cynthia Keppel, J. A. Dunne, S. Danagoulian, Donal Day, M. Ungaro, G. R. Smith, Dipangkar Dutta, K. Joo, S. Malace, I. Niculescu, J. Arrington, T. Angelescu, L. Tang, and J. Roche

Subjects
Nuclear physics, Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle decay, Particle physics, Amplitude, Meson, Momentum transfer, Perturbative QCD, Resonance (particle physics), Helicity
Abstract

The differential cross-section for the exclusive process p(e, e0p) has been measured at Q2 5.7 and 7.0 (GeV/c)2, which represents the highest momentum transfer measurement of this to date, significantly higher than the previous highest at Q2 3.6 (GeV/c)2. Data was taken for centre-of-mass energies from threshold to 1.8 GeV, encompassing the S11(1535) resonance, which dominates the pη channel. The total cross section is obtained, from which is extracted the helicity-conserving transition amplitude A1/2, for the production of the S11(1535) resonance. This quantity appears to begin scaling as Q-3, a predicted signal of the dominance of perturbative QCD, within the Q2 range of this measurement. No currently available theoretical predictions can account for the behaviour of this quantity over the full measured range of Q2.

Published
2009

21. Elastic magnetic electron scattering fromC13atQ2=1GeV2/c2

Author

R. A. Miskimen, M. Frodyma, W. Turchinetz, K. S. Lee, J. Martino, K. A. Dow, S. H. Rokni, R. S. Hicks, S. E. Rock, R.L. Huffman, G. A. Peterson, P. E. Bosted, A. Hotta, B. Frois, S.K. Platchkov, J. D. Zumbro, and H. Baghaei

Subjects
Physics, Elastic scattering, Nuclear reaction, Nuclear and High Energy Physics, Scattering, Momentum transfer, Form factor (quantum field theory), Atomic physics, Ground state, Electron scattering, Omega
Abstract

Electron scattering from {sup 13}C was measured at a momentum transfer of 5.08 fm{sup {minus}1}. No electron events were observed in the vicinity of the elastic peak, giving an upper limit for the elastic cross section of 1.2{times}10{sup {minus}39} cm{sup 2}/sr with a confidence level of 90%. At this momentum transfer, the square of the elastic {ital M}1 form factor apparently continues to fall exponentially with {ital q}. Comparison of the data with shell-model calculations indicates that admixtures of 2{h bar}{omega} configurations in the {sup 13}C ground state cannot entirely explain the high-{ital q} enhancement of the {ital M}1 form factor relative to 1{ital p}-shell calculations.

Published
1991

22. Fast tracking in a trigger system based on a memory lookup unit

Author

Eli Piasetzky, J. Alster, A. Navon, Yael Mardor, I. Navon, and S. E. Rock

Subjects
Physics, Nuclear and High Energy Physics, Spectrometer, business.industry, Event (computing), Fortran, Tracking (particle physics), Software, Logic gate, Table (database), business, Instrumentation, computer, Computer hardware, Electronic circuit, computer.programming_language
Abstract

One section of a fast tracking trigger system for a proposed large particle spectrometer is presented. This subsystem is based on a novel use of a memory lookup unit. The electronic circuit and the associated software table are described in detail. The subsystem can accomplish the tracking for a complex event in a few microseconds. A prototype subsystem was assembled and tested successfully.

Published
1991

23. Cross sections for hard exclusive electroproduction of pi(+) mesons on a hydrogen target

Author

W. Augustyniak, A. López Ruiz, Vitaly Shutov, H. P. Blok, Y. Van Haarlem, M. Hoek, M. Kopytin, A. Nass, V. A. Gapienko, N. Bianchi, Wolfgang Lorenzon, Ivana Hristova, C. B. Van Hulse, A. Ivanilov, P. E. Reimer, S. Yaschenko, H. Böttcher, E. De Sanctis, V. Gharibyan, C. Shearer, B. Seitz, E. Nappi, P. B. van der Nat, P. Lenisa, Z. Akopov, Arne Vandenbroucke, P. Zupranski, G. Gapienko, Andreas Mussgiller, A. Trzcinski, Riccardo Fabbri, T. A. Shibata, A. Kisselev, J. G. Rubin, I. Lehmann, E. Avetissian, H. Ye, S. Lu, S. Frullani, V. Muccifora, G. Rosner, G. Hill, Morgan Murray, N. Pickert, M. Statera, W.-D. Nowak, L. A. Linden-Levy, H. Guler, G. Ciullo, S. E. Rock, Y. Salomatin, Dirk Ryckbosch, M. Negodaev, A. Airapetian, W. Yu, G. Schnell, D. Zeiler, S. Joosten, J. Streit, A. Hillenbrand, Y. Imazu, C. Vogel, A. Borissov, H. E. Jackson, L. L. Pappalardo, K. P. Schüler, P.F. Dalpiaz, Stephen V. Gliske, L. Barion, S. Yen, V. G. Krivokhijine, Hasko Stenzel, E. Thomas, F. Stinzing, C. Bonomo, V. A. Korotkov, Shan Wang, L. Lapikás, F. Giordano, T. Keri, L. Lagamba, Ralf Kaiser, M. Ehrenfried, M. Varanda, P. Di Nezza, R. De Leo, R. Perez-Benito, B. Marianski, R. Lamb, H. Marukyan, D. Hasch, J. J. M. Steijger, C. Riedl, G. Elbakian, Michael Düren, M. Stancari, V. Vikhrov, L. Rubacek, M. Diefenthaler, G. Gavrilov, S. Belostotski, V. Bryzgalov, C. A. Miller, M. Capiluppi, A. Rostomyan, A. Avetissian, F. Garibaldi, A. Fantoni, D. Gabbert, J. Stewart, A. R. Reolon, L. De Nardo, Zhenyu Ye, Frank Ellinghaus, Michael Tytgat, E. Cisbani, E. R. Kinney, I. Vilardi, S. Taroian, X. R. Lu, Y. Naryshkin, M. Contalbrigo, Martin Raithel, E. C. Aschenauer, B. Zihlmann, Y. Miyachi, Naomi C R Makins, P. Kravchenko, Alexander Ilyichev, Wouter Deconinck, N. Akopov, D. Veretennikov, M. Demey, G.P. Capitani, Klaus Rith, J. Burns, C. Hadjidakis, J. Dreschler, G. van der Steenhoven, David Mahon, Andreas Schäfer, (Astro)-Particles Physics, and Student Lab and Education

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Scattering, Four-momentum, Virtual particle, FOS: Physical sciences, DESY, Parton, Electron, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Positron, 0103 physical sciences, ddc:530, High Energy Physics::Experiment, 010306 general physics, Nuclear Experiment, SDG 6 - Clean Water and Sanitation
Abstract

The exclusive electroproduction of pi+ mesons was studied with the Hermes spectrometer at the DESY laboratory by scattering 27.6 GeV positron and electron beams off an internal hydrogen gas target. The virtual-photon cross sections were measured as a function of the Mandelstam variable t and the squared four momentum -Q^2 of the exchanged virtual photon. A model calculation based on Generalized Parton Distributions is in fair agreement with the data at low values of |t| if power corrections are included. A model calculation based on the Regge formalism gives a good description of the magnitude and the t and Q^2 dependences of the cross section., Comment: 7 pages, 5 figures, revised text

Published
2008

24. Transverse electrodisintegration of the deuteron in the threshold region at highQ2

Author

J. Lichtenstadt, J. Alster, F. S. Dietrich, R. A. Gearhart, G. deChambrier, G. A. Peterson, D. Benton, G. G. Petratos, R. S. Hicks, P. E. Bosted, van Bibber K, M. Frodyma, A. Lung, A. A. Rahbar, A. Hotta, Z. M. Szalata, J. Lambert, S. E. Rock, A. T. Katramatou, B. Debebe, R. G. Arnold, and L. Clogher

Subjects
Quark, Elastic scattering, Physics, Nuclear reaction, Nuclear and High Energy Physics, Scattering, Computer Science::Information Retrieval, Nuclear Theory, Impulse (physics), Inelastic scattering, Charged particle, Deuterium, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment
Abstract

Cross sections for 180{degree} deuteron electrodisintegration have been measured near threshold for the {ital Q}{sup 2} range 1.21 to 2.77 (GeV/{ital c}){sup 2}. The data are compared to several nonrelativistic meson-nucleon and hybrid quark-hadron models. The data are in strong disagreement with the impulse approximation, indicating the importance of non-nucleonic degrees of freedom. None of the models are in good agreement with the data at all values of {ital Q}{sup 2}. The ratio {ital W}{sub 1}/{ital W}{sub 2} of inelastic structure functions has been extracted using previous forward angle data and is found to decrease strongly near threshold, also indicating the importance of interaction effects.

Published
1990

25. Transverse momentum dependence of semi-inclusive pion production

Author

G. Niculescu, E. Segbefia, A. N. Villano, V. V. Frolov, I. Niculescu, V. Tadevosyan, T. Horn, X. Zheng, Y. Cui, T. Angelescu, X. Jiang, S. Vidakovic, E. V. Hungerford, A. K. Opper, E. McGrath, Glen A. Warren, H. Breuer, Donal Day, S. A. Wood, V. P. Kubarovsky, P. Stoler, O. K. Baker, Pete Markowitz, N. Kalantarians, C. Xu, L. Yuan, R. J. Holt, H. Mkrtchyan, T. Dodario, C. Bertoncini, M. M. Dalton, L. G. Tang, T. Ostapenko, Y. Li, J. A. Dunne, Curtis Smith, K. Hafidi, B. Moziak, E. Schulte, W. F. Vulcan, John Arrington, S. E. Rock, A. Uzzle, A. Ahmidouch, Bogdan Wojtsekhowski, James J. Kelly, H. C. Fenker, N. Benmouna, Hongbo Zhu, M. K. Jones, C. E. Keppel, N. El Khayari, P. Bosted, G. S. Adams, F. R. Wesselmann, R. Asaturyan, K. Joo, Rolf Ent, Dipangkar Dutta, D. G. Meekins, P. McKee, S. Danagoulian, M. E. Christy, L. Gan, W. U. Boeglin, M. Ungaro, G. R. Smith, D. Gaskell, W. Hinton, H. P. Blok, G. M. Huber, J. Reinhold, S. Malace, T. Navasardyan, P. E. Reimer, Y. Liang, M. Wang, Simon Henry Connell, J. Roche, and (Astro)-Particles Physics

Subjects
Quark, Physics, Scattering cross-section, Nuclear and High Energy Physics, Particle physics, Proton, Physics::Instrumentation and Detectors, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Nuclear Theory, FOS: Physical sciences, Nuclear physics, Transverse plane, High Energy Physics - Phenomenology, Pion, High Energy Physics - Phenomenology (hep-ph), Deuterium, Transverse momentum, Fragmentation function, High Energy Physics::Experiment, SDG 6 - Clean Water and Sanitation, Nuclear Experiment, Astrophysics::Galaxy Astrophysics
Abstract

Cross sections for semi-inclusive electroproduction of charged pions ($\pi^{\pm}$) from both proton and deuteron targets were measured for $0.2, Comment: 15 pages, 4 figures. Fit form changed to include Cahn effect Minor revisions. Added one new figure

Published
2007

26. Onset of Quark-Hadron Duality in Pion Electroproduction

Author

W. Hinton, S. E. Rock, Glen A. Warren, S. Danagoulian, Y. Cui, T. Angelescu, R. J. Holt, D. G. Meekins, P. Stoler, Hongbo Zhu, G. S. Adams, K. Joo, Rolf Ent, W. U. Boeglin, F. R. Wesselmann, G. Niculescu, M. K. Jones, P. E. Reimer, S. Vidakovic, V. Tadevosyan, B. Moziak, A. N. Villano, Geoffrey Smith, J. A. Dunne, X. Jiang, T. Horn, Y. Li, John Arrington, Donal Day, V. V. Frolov, Y. Liang, James J. Kelly, M. Wang, M. E. Christy, H. Mkrtchyan, O. K. Baker, T. Navasardyan, S. A. Wood, E. Segbefia, N. Kalantarians, A. Ahmidouch, N. El Khayari, H. Breuer, Curtis Smith, C. Bertoncini, M. M. Dalton, R. Asaturyan, K. Hafidi, Simon Henry Connell, D. Gaskell, Pete Markowitz, C. E. Keppel, A. Uzzle, N. Benmouna, C. Xu, I. Niculescu, L. Yuan, G. M. Huber, E. Schulte, H. C. Fenker, P. Bosted, P. McKee, L. Gan, J. Roche, T. Dodario, T. Ostapenko, W. F. Vulcan, L. G. Tang, M. Ungaro, H. P. Blok, J. Reinhold, S. Malace, Bogdan Wojtsekhowski, Dipangkar Dutta, X. Zheng, V. Kubarovski, E. V. Hungerford, A. K. Opper, E. McGrath, and (Astro)-Particles Physics

Subjects
Quark, Physics, Particle physics, 010308 nuclear & particles physics, Scattering, High Energy Physics::Lattice, Hadron, High Energy Physics::Phenomenology, Nuclear Theory, General Physics and Astronomy, FOS: Physical sciences, Electron, 01 natural sciences, Duality (electricity and magnetism), Nuclear physics, High Energy Physics - Phenomenology, Pion, High Energy Physics - Phenomenology (hep-ph), Factorization, 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Nuclear Experiment, Ansatz
Abstract

A large data set of charged-pion electroproduction from both hydrogen and deuterium targets has been obtained spanning the low-energy residual-mass region. These data conclusively show the onset of the quark-hadron duality phenomenon, as predicted for high-energy hadron electroproduction. We construct several ratios from these data to exhibit the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark-to- pion production mechanisms., Comment: 11 pages, 3 figures, accepted in Phys. Rev. Lett. Tables added

Published
2007

27. Precision measurement of the weak mixing angle in Møller scattering

Author

J. Cahoon, R. Holmes, M. Woods, K. S. Kumar, A. Deur, Jaideep Singh, R. D. McKeown, W. Emam, M. Olson, Joshua J. Turner, Jiansong Gao, M. Gary, D. Lhuillier, Z. M. Szalata, Paul Souder, G. R. Bower, D. Relyea, M. Cooke, J. P. Chen, G. M. Jones, P. Decowski, R. Erickson, I. Younus, E. W. Hughes, G. A. Peterson, O. H. Saxton, Antonin Vacheret, Zach Marshall, R. S. Hicks, R. G. Arnold, T. Fieguth, K. Bega, R. Michaels, Yu. G. Kolomensky, Kent Paschke, R. Pitthan, S. E. Rock, R. M. Lombard-Nelsen, J. Weisend, D. Walz, K. Gustafsson, Peter S. LaViolette, L. Keller, C. Arroyo, T. Weber, C. Field, E. Chudakov, P. Bosted, P. Mastromarino, B. Tweedie, L. J. Kaufman, J. Niedziela, J. Biesiada, G. D. Cates, P.L. Anthony, T. B. Humensky, and R. Carr

Subjects
Elastic scattering, Physics, Particle physics, Scattering, media_common.quotation_subject, General Physics and Astronomy, FOS: Physical sciences, Elementary particle, Weinberg angle, Fermion, Asymmetry, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), High Energy Physics::Experiment, Møller scattering, Atomic physics, Lepton, media_common
Abstract

We report on a precision measurement of the parity-violating asymmetry in fixed target electron-electron (Moller) scattering: A_PV = -131 +/- 14 (stat.) +/- 10 (syst.) parts per billion, leading to the determination of the weak mixing angle \sin^2\theta_W^eff = 0.2397 +/- 0.0010 (stat.) +/- 0.0008 (syst.), evaluated at Q^2 = 0.026 GeV^2. Combining this result with the measurements of \sin^2\theta_W^eff at the Z^0 pole, the running of the weak mixing angle is observed with over 6 sigma significance. The measurement sets constraints on new physics effects at the TeV scale., Comment: 4 pages, 2 postscript figues, submitted to Physical Review Letters

Published
2005

28. Observation of Parity Nonconservation in Moller Scattering

Author

E. Chudakov, C. Arroyo, F.-J. Decker, D.H. Whittum, K. Baird, Gilbert Shapiro, R. Carr, T. Fieguth, T. Weber, C. Field, M. Woods, R. Michaels, W. Emam, J. Biesiada, K. Pope, R. G. Arnold, Baris T. Tonguc, Gordon D. Cates, K. Bega, R. M. Lombard-Nelsen, K. S. Kumar, R. Pitthan, Jaideep Singh, J. Weisend, Z. M. Szalata, B. Mayer, O. H. Saxton, P. Bosted, M. Olson, W. A. Tobias, M. Cooke, B. Tweedie, Yu. G. Kolomensky, L. J. Kaufman, Matthew L. Breuer, G. A. Peterson, Jiansong Gao, A. Deur, R. D. McKeown, J. P. Chen, E. W. Hughes, P.L. Anthony, Joshua J. Turner, Paul Souder, D. Relyea, P. Decowski, R. Erickson, R. Holmes, D. Lhuillier, Antonin Vacheret, T. B. Humensky, G. M. Jones, R. S. Hicks, Kent Paschke, P. Mastromarino, S. E. Rock, I. Younus, D. Walz, and K. Gustafsson

Subjects
Elastic scattering, Physics, Particle physics, 010308 nuclear & particles physics, Scattering, media_common.quotation_subject, General Physics and Astronomy, FOS: Physical sciences, Parity (physics), Electron, 01 natural sciences, Asymmetry, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, Grand Unified Theory, High Energy Physics::Experiment, Møller scattering, Quantum field theory, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, media_common
Abstract

We report a measurement of the parity-violating asymmetry in fixed target electron-electron (Moller) scattering: A_PV = -175 +/- 30 (stat.) +/- 20 (syst.) parts per billion. This first direct observation of parity nonconservation in Moller scattering leads to a measurement of the electron's weak charge at low energy Q^e_W = -0.053 +/- 0.011. This is consistent with the Standard Model expectation at the current level of precision: sin^2\theta_W(M_Z)_MSbar = 0.2293 +/- 0.0024 (stat.) +/- 0.0016 (syst.) +/- 0.0006 (theory)., Comment: Version 3 is the same as version 2. These versions contain minor text changes from referee comments and a change in the extracted value of Q^e_W and sin^2\theta_W due to a change in the theoretical calculation of the bremsstrahulung correction (ref. 16)

Published
2003

29. Measurement of the Proton Spin Structure Functiong1(x,Q2)forQ2from 0.15 to1.6 GeV2with CLAS

Author

S. J. Gaff, D. Doughty, M. Seely, G. Ricco, D. Heddle, R. J. Feuerbach, Philip L. Cole, C. S. Whisnant, L. Farhi, Bernhard Mecking, V. Sapunenko, Dinko Pocanic, Valeria Muccifora, K. V. Dharmawardane, C. D. Keith, P. Eugenio, Shalev Gilad, M. Taiuti, M. Guillo, Gerard Gilfoyle, S. E. Kuhn, R. A. Niyazov, John T. O'Brien, S. Strauch, Friedrich Klein, L. C. Dennis, B. E. Bonner, B. Carnahan, F. Sabatié, W. K. Brooks, L. M. Qin, P. Corvisiero, J. H. Kelley, R. S. Hicks, Brian Raue, Jing Zhao, William Bertozzi, C. Tur, S. Mehrabyan, D. Protopopescu, J. P. Cummings, H. R. Weller, Volker D. Burkert, C. Cetina, A. S. Biselli, S. Pozdniakov, M. Garçon, Thierry Auger, J. R. Calarco, F. W. Hersman, K. S. Egiyan, V. Koubarovski, K. Mikhailov, E. Anciant, Michael Vineyard, Baile Zhang, E. Pasyuk, B. M. Preedom, G. V. O'Rielly, L. Elouadrhiri, Z. L. Zhou, C. Butuceanu, M. Kossov, W. Kim, E. Wolin, R. A. Miskimen, S. A. Dytman, M. Ripani, J. P. Santoro, C. E. Hyde-Wright, J. Hu, D. Branford, Rakhsha Nasseripour, M. Khandaker, A. V. Skabelin, G. S. Mutchler, D. G. Jenkins, Susan Taylor, H. Egiyan, K. Sabourov, J. P. Ball, Y. Prok, M. Eckhause, M. Sargsyan, D. G. Crabb, M. Spraker, Y. Ilieva, Patrick Girard, J. Shaw, Michael Wood, M. Mirazita, J. M. Laget, K. Wang, C. Salgado, P. E. Bosted, A. P. Freyberger, Harut Avakian, Y. Kuang, K. Y. Kim, C. Marchand, Laird Kramer, V. S. Serov, S. McAleer, E. Polli, M. Battaglieri, M. Bellis, K. Park, Federico Ronchetti, K. A. Griffioen, Roy Thompson, V. Frolov, Elton Smith, M. Guidal, R. Bradford, M. M. Ito, J. Ficenec, G. Niculescu, L. Ciciani, A. Longhi, M. Klusman, Ji Li, L. Todor, R. Clark, P. Heimberg, Jens H. Kuhn, M. Holtrop, Thomas E. Smith, M. Anghinolfi, M. D. Mestayer, A. Empl, O. Pogorelko, S. Simionatto, J. D. Kellie, S. Stepanyan, Nicola Bianchi, K. Lukashin, Sylvain Bouchigny, K. Livingston, James Mueller, H. Funsten, Cynthia Marie Hadjidakis, K. L. Giovanetti, B. Asavapibhop, P. Rossi, S. Boiarinov, P. D. Rubin, J. W. Price, Michael Dugger, Larry Weinstein, M. Osipenko, Y. G. Sharabian, H. Denizli, Daniel S. Carman, G. Audit, K. Beard, G. A. Peterson, J. Connelly, Kalvir S. Dhuga, Alexei V. Klimenko, S. Barrow, M. Bektasoglu, G. Gavalian, Barry Ritchie, M. Nozar, R. C. Minehart, C. A. Meyer, P. Stoler, S. O. Nelson, K. Hicks, R. Fatemi, A. V. Vlassov, R. De Vita, J. J. Manak, E. De Sanctis, D. I. Sober, A.V. Stavinsky, L. Sorrel, D. J. Tedeschi, V. Gyurjyan, H. Bagdasaryan, D. Hancock, L. Guo, M. Ungaro, P. Dragovitsch, S. Niccolai, K. Joo, J. Yun, J. Hardie, D. Cords, A. Yegneswaran, G. E. Dodge, P. V. Degtyarenko, K. Kim, I. Niculescu, D. Lawrence, R. A. Schumacher, J. Lachniet, D. Rowntree, C. I O Gordon, L. Morand, T. A. Forest, A. Coleman, B. B. Niczyporuk, N. Pivnyuk, S. E. Rock, Avraham Klein, J. Napolitano, W. Major, G. S. Adams, Hall Crannell, G. Riccardi, J. W C McNabb, S. A. Morrow, C. Djalali, U. Thoma, D. P. Weygand, and L. C. Smith

Subjects
Physics, Nuclear physics, Particle physics, Scattering, Proton spin crisis, General Physics and Astronomy, Electron, Nucleon, Parametrization, Resonance (particle physics), Scaling, Sign (mathematics)
Abstract

Double-polarization asymmetries for inclusive $ep$ scattering were measured at Jefferson Lab using 2.6 and 4.3 GeV longitudinally polarized electrons incident on a longitudinally polarized NH$_3$ target in the CLAS detector. The polarized structure function $g_1(x,Q^2)$ was extracted throughout the nucleon resonance region and into the deep inelastic regime, for $Q^2 = 0.15 -1.64 $GeV$^2$. The contributions to the first moment $\Gamma_1(Q^2) = \int g_1(x,Q^2)dx$ were determined up to $Q^2=1.2$ GeV$^2$. Using a parametrization for $g_1$ in the unmeasured low $x$ regions, the complete first moment was estimated over this $Q^2$ region. A rapid change in $\Gamma_1$ is observed for $Q^2 < 1 $GeV$^2$, with a sign change near $Q^2 = 0.3 $GeV$^2$, indicating dominant contributions from the resonance region. At $Q^2=1.2$ GeV$^2$ our data are below the pQCD evolved scaling value.

Published
2003

30. Threshold electrodisintegration of3He

Author

Hiroyuki Kamada, W. Glöckle, W. Turchinetz, A. Hotta, R. S. Hicks, X. Jiang, M. C. Berisso, A. Nogga, R. Skibiński, Jacek Golak, B. Asavapibhop, F. Casagrande, A. Cichocki, K. Burchesky, P. Bosted, G. A. Peterson, Tadaaki Tamae, S. E. Rock, J. Shaw, T. Kobayashi, I. Nakagawa, K. Wang, Henryk Witała, Toshio Suda, S. Churchwell, and R. A. Miskimen

Subjects
Physics, Nuclear and High Energy Physics, Cross section.transverse, 010308 nuclear & particles physics, Nuclear Theory, Momentum transfer, Relativistic dynamics, 01 natural sciences, Nuclear physics, Momentum, Transverse plane, 0103 physical sciences, Nuclear force, 010306 general physics
Abstract

Cross sections were measured for the near-threshold electrodisintegration of ${}^{3}\mathrm{He}$ at momentum transfer values of $q=2.4,$ $4.4,$ and $4.7{\mathrm{fm}}^{\ensuremath{-}1}.$ From these and prior measurements the transverse and longitudinal response functions ${R}_{T}$ and ${R}_{L}$ were deduced. Comparisons are made against previously published and new nonrelativistic $A=3$ calculations using the best available nucleon-nucleon NN potentials. In general, for $ql2{\mathrm{fm}}^{\ensuremath{-}1}$ these calculations accurately predict the threshold electrodisintegration of ${}^{3}\mathrm{He}.$ Agreement at increasing q demands consideration of two-body terms, but discrepancies still appear at the highest momentum transfers probed, perhaps due to the neglect of relativistic dynamics, or to the underestimation of high-momentum wave-function components.

Published
2003

31. Single Spin Asymmetry in Open Charm Photoproduction and Decay as a Test of pQCD

Author

K. A. Griffioen, S. E. Rock, N. Ya. Ivanov, and Peter E. Bosted

Subjects
Quark, Physics, Nuclear and High Energy Physics, Particle physics, Photon, 010308 nuclear & particles physics, Linear polarization, media_common.quotation_subject, High Energy Physics::Phenomenology, FOS: Physical sciences, 01 natural sciences, 7. Clean energy, Asymmetry, Spectral line, 3. Good health, Gluon, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Nuclear Experiment, media_common, Fermi Gamma-ray Space Telescope, Lepton
Abstract

We analyze the possibility of measuring the single spin asymmetry (SSA) in open charm production by linearly polarized photons in the planned E160/E161 experiments at SLAC using the inclusive spectra of secondary (decay) leptons. In leading order pQCD, the SSA in the azimuthal distribution of the charged decay lepton is predicted to be about 0.2 for SLAC kinematics. Our calculations show that the SSA in the decay lepton distribution is well defined in pQCD: it is stable both perturbatively and parametrically, and practically insensitive to theoretical uncertainties in the charm semileptonic decays. Nonperturbative contributions to the leptonic SSA due to the gluon transverse motion in the target, heavy quark fragmentation and Fermi motion of the $c$-quark inside the $D$-meson are predicted to be about 10%. We conclude that measurements of the azimuthal asymmetry in the secondary lepton distribution would provide a good test of the applicability of pQCD to open charm production at energies of fixed target experiments. Our analysis of the SLAC experimental conditions shows that this SSA can be measured in E160/E161 with an accuracy of about ten percent., Comment: 18 pages, 10 figures, RevTeX, references corrected

Published
2002
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32. Measurement of the elastic magnetic form factor of (3)He at high momentum transfer

Author

I, Nakagawa, J, Shaw, S, Churchwell, X, Jiang, B, Asavapibhop, M C, Berisso, P E, Bosted, K, Burchesky, F, Casagrande, A, Cichocki, R S, Hicks, A, Hotta, T, Kobayashi, R A, Miskimen, G A, Peterson, S E, Rock, T, Suda, T, Tamae, W, Turchinetz, and K, Wang

Abstract

New electron scattering measurements have been made that extend data on the (3)He elastic magnetic form factor up to Q(2) = 42.6 fm(-2). These new data test theoretical conjectures regarding non-nucleonic effects in the three-body system. The very small cross sections, as low as 10(-40) cm(2)/sr, required the use of a high-pressure cryogenic gas target and a detector system with excellent background rejection capability. No existing theoretical calculation satisfactorily accounts for all the available data.

Published
2000

33. Measurements of the proton and deuteron spin structure functionsg1andg2

Author

Timothy Chupp, R. Gearhart, S.St. Lorant, Koji Abe, D. Kawall, P. Raines, C. Y. Prescott, H. Fonvieille, F. S. Dietrich, L. S. Rochester, J. P. Chen, D. Crabb, M. Kuriki, Ch. Hyde-Wright, T. Averett, A. Rijllart, J. Clendenin, J. Morgenstern, Donal Day, L. C. Smith, R. C. Minehart, R. Erbacher, Z. E. Meziani, F. Staley, G. Court, B. Zihlmann, R. Prepost, Emil Frlez, J. R. Johnson, P. Grenier, Timothy B. Smith, Y. Roblin, R. Antonov, R. M. Lombard-Nelsen, C. C. Young, Avraham Klein, R. Pitthan, T. J. Liu, Dinko Pocanic, J. S. McCarthy, R. A. Lindgren, F. Suekane, G. G. Petratos, Ingo Sick, J. Fellbaum, J. Button-Shafer, H. Borel, K. A. Griffioen, S. E. Kuhn, K. Witte, John C. Mitchell, A. Feltham, E. W. Hughes, D. Walz, F.R. Wesselmann, P. E. Bosted, Z. M. Szalata, D. Garvey, J. M. Bauer, Y. Terrien, T. L. Usher, B. Raue, S. Hoibraten, Pascal Steiner, D. Zimmermann, Vincent Breton, H. R. Band, O. Rondon, H. Tang, K. P. Coulter, S. E. Rock, J. Gomez, R. G. Arnold, L. M. Stuart, T. Maruyama, D. Reyna, J. A. Dunne, X.K. Maruyama, C. Comptour, M. Daoudi, T. Akagi, M. Spengos, H. Yuta, P.L. Anthony, W. Meyer, G. H. Zapalac, H. Dutz, J. Marroncle, B. Youngman, and James L. White

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Proton, Deuterium, Full data, Zero (complex analysis), Resonance, Spin structure, Beam energy
Abstract

Measurements are reported of the proton and deuteron spin structure functions ${g}_{1}^{p}$ and ${g}_{1}^{d}$ at beam energies of 29.1, 16.2, and 9.7 GeV, and ${g}_{2}^{p}$ and ${g}_{2}^{d}$ at a beam energy of 29.1 GeV. The integrals ${\ensuremath{\Gamma}}_{p}={\ensuremath{\int}}_{0}^{1}{g}_{1}^{p}{(x,Q}^{2})dx$ and ${\ensuremath{\Gamma}}_{d}={\ensuremath{\int}}_{0}^{1}{g}_{1}^{d}{(x,Q}^{2})dx$ were evaluated at fixed ${Q}^{2}=3(\mathrm{GeV}{/c)}^{2}$ using the full data set to yield ${\ensuremath{\Gamma}}_{p}=0.132\ifmmode\pm\else\textpm\fi{}0.003(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.009(\mathrm{syst})$ and ${\ensuremath{\Gamma}}_{d}=0.047\ifmmode\pm\else\textpm\fi{}0.003\ifmmode\pm\else\textpm\fi{}0.006.$ The ${Q}^{2}$ dependence of the ratio ${g}_{1}{/F}_{1}$ was studied and found to be small for ${Q}^{2}g1(\mathrm{GeV}{/c)}^{2}.$ Within experimental precision the ${g}_{2}$ data are well described by the twist-2 contribution, ${g}_{2}^{\mathrm{WW}}.$ Twist-3 matrix elements were extracted and compared to theoretical predictions. The asymmetry ${A}_{2}$ was measured and found to be significantly smaller than the positivity limit $\sqrt{R}$ for both proton and deuteron targets. ${A}_{2}^{p}$ is found to be positive and inconsistent with zero. Measurements of ${g}_{1}$ in the resonance region show strong variations with $x$ and ${Q}^{2},$ consistent with resonant amplitudes extracted from unpolarized data. These data allow us to study the ${Q}^{2}$ dependence of the integrals ${\ensuremath{\Gamma}}_{p}$ and ${\ensuremath{\Gamma}}_{n}$ below the scaling region.

Published
1998

34. Measurements of theΔ(1232)transition form factor and the ratioσn/σpfrom inelastic electron-proton and electron-deuteron scattering

Author

P. E. Bosted, Sayed Rokni, R. A. Gearhart, M. Spengos, G. A. Peterson, K. Swartz, K. A. Griffioen, A. Lung, J. Lichtenstadt, S. E. Rock, S. E. Kuhn, L. Andivahis, R. G. Arnold, L. H. Tao, J. Gomez, W. R. Dodge, J. Alster, C. E. Hyde-Wright, L. M. Stuart, F. S. Dietrich, G. G. Petratos, Sakumoto Wk, R. S. Hicks, Z. M. Szalata, C. C. Chang, C. E. Keppel, and R. A. Miskimen

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Proton, Deuterium, Scattering, Form factor (quantum field theory), Resonance, Perturbative QCD, Production (computer science), Atomic physics, Deep inelastic scattering
Abstract

Measurements of inclusive electron-scattering cross sections using hydrogen and deuterium targets in the region of the $\ensuremath{\Delta}(1232)$ resonance are reported. A global fit to these new data and previous data in the resonance region is also reported for the proton. Transition form factors have been extracted from the proton cross sections for this experiment over the four-momentum transfer squared range $1.64l{Q}^{2}l6.75 (\mathrm{GeV}{/c)}^{2}$ and from previous data over the range $2.41l{Q}^{2}l9.82 (\mathrm{GeV}{/c)}^{2}.$ The results confirm previous reports that the $\ensuremath{\Delta}(1232)$ transition form factor decreases more rapidly with ${Q}^{2}$ than expected from perturbative QCD. The ratio of ${\ensuremath{\sigma}}_{n}/{\ensuremath{\sigma}}_{p}$ in the $\ensuremath{\Delta}(1232)$ resonance region has been extracted from the deuteron data for this experiment in the range $1.64l{Q}^{2}l3.75 (\mathrm{G}\mathrm{e}\mathrm{V}/{c)}^{2}$ and for a previous experiment in the range $2.4l{Q}^{2}l7.9 (\mathrm{GeV}{/c)}^{2}.$ A study has been made of the model dependence of these results. This ratio ${\ensuremath{\sigma}}_{n}/{\ensuremath{\sigma}}_{p}$ for $\ensuremath{\Delta}(1232)$ production is slightly less than unity, while ${\ensuremath{\sigma}}_{n}/{\ensuremath{\sigma}}_{p}$ for the nonresonant cross sections is approximately 0.5, which is consistent with deep inelastic scattering results.

Published
1998

35. Large enhancement of deuteron polarization with frequency modulated microwaves

Author

J. Vogt, A. Nagaitsev, John C. Mitchell, A. Magnon, D. Crabb, Iskender Atilla Reyhancan, H. J. Kessler, Roland Windmolders, VW Hughes, Kwong Lau, J. Kyynäräinen, I.A. Savin, F. Tessarotto, J. Çuhadar, D. Peshekhonov, E. Rondio, R. Kaiser, A. Arvidson, J. Nassalski, B. W. Mayes, J. H. Moromisato, A. Brüll, C.S. Ozben, J. Pretz, J. Martino, L. Ropelewski, S. Dalla Torre, G. Gracia, T. Matsuda, Gerhard K. Mallot, K. M. Teichert, Anna Zanetti, M. Lowe, A. Rijllart, M. Plo, C. Garabatos, T. Kageya, Jay Roberts, T. Lindqvist, D. Sanders, J. M. Rieubland, M. Grosse Perdekamp, P. Björkholm, Bernardo Adeva, C. A. Whitten, C. Cavata, M. Boutemeur, A. Witzmann, A. Ogawa, J.M. Clement, V. Kukhtin, Abhay Deshpande, G. Salvato, Roy Weinstein, S. Ishimoto, N. De Groot, Takahiro Iwata, F. Feinstein, D. Pose, Alessandro Bressan, N. Horikawa, Heinrich B. Stuhrmann, J. P. Chen, M. Clocchiatti, I. Bird, D. von Harrach, I. Kiryushin, B. Frois, J. Zhao, H. Postma, Yannis K. Semertzidis, J. Pyrlik, N. de Botton, Aina Yañez, J. Saborido, M. Lamanna, G.S. Mutchler, R. van Dantzig, L. Betev, B. Neganov, T. O. Niinikoski, B. E. Bonner, Etienne Burtin, S. E. Rock, Regine Willumeit, I. Sabo, A. Dyring, J.A. Buchanan, Sergey M. Sergeev, V. G. Krivokhijine, Rudiger Voss, J. S. McCarthy, G. van Middelkoop, S. Bültmann, E. Arik, C. A. Heusch, P. Shanahan, E. P. Sichtermann, S. Platchkov, David Miller, J. Lichtenstadt, L. Naumann, Cristino Pérez, M. K. Ballintijn, G.I. Smirnov, T. Hasegawa, T. Layda, C. Dulya, A. Kishi, Patrick Hautle, J. M. Le Goff, A. Rosado, F. Lehar, Ricardo Piegaia, G. Bardin, M. Giorgi, Shafqat Ahmad, A. de Lesquen, F. Sever, Donal Day, R. E. Segel, E. Gülmez, E. M. Kabuß, D. Fasching, S. Lopez-Ponte, T. Pussieux, D. Krämer, A. Sandacz, W. Wislicki, A. Steinmetz, Alan D. Martin, F. Marie, I. A. Golutvin, Ulrich Landgraf, W. Thiel, M. Litmaath, M. Velasco, O. Rondon, S. Eichblatt, M. D. Corcoran, Günter Baum, J. E.J. Oberski, P. Berglund, T. Gaussiran, E. von Goeler, A. Staude, Aldo Penzo, J. Cranshaw, N. Zamiatin, T. J. Ketel, Shoji Okumi, L. Klostermann, R. Seitz, B. Badelek, C. Fernandez, N. Hayashi, R. Birsa, M. Rodriguez, F. Perrot-Kunne, A. Karev, Lawrence Pinsky, Kunikazu Mori, J. C. Faivre, G. Igo, K. Medved, Andrés Gómez, J. A. Garzon, Franco Bradamante, P. Schiavon, Y. Kisselev, M. de Jong, K. P. Schüler, S. Dhawan, and (Astro)-Particles Physics

Subjects
Physics, Nuclear and High Energy Physics, Polarization rotator, Absorption spectroscopy, Scattering, business.industry, FOS: Physical sciences, DYNAMIC NUCLEAR-POLARIZATION, TARGET, Polarization (waves), law.invention, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Optics, Deuterium, law, Nuclear Experiment (nucl-ex), Atomic physics, Detectors and Experimental Techniques, business, Electron paramagnetic resonance, Nuclear Experiment, Instrumentation, Frequency modulation, Microwave
Abstract

We report a large enhancement of 1.7 in deuteron polarization up to values of 0.6 due to frequency modulation of the polarizing microwaves in a two liters polarized target using the method of dynamic nuclear polarization. This target was used during a deep inelastic polarized muon-deuteron scattering experiment at CERN. Measurements of the electron paramagnetic resonance absorption spectra show that frequency modulation gives rise to additional microwave absorption in the spectral wings. Although these results are not understood theoretically, they may provide a useful testing ground for the deeper understanding of dynamic nuclear polarization., 10 pages, including the figures coming in uuencoded compressed tar files in poltar.uu, which also brings cernart.sty and crna12.sty files needed

Published
1995

36. Two body photodisintegration of the deuteron up to 2.8 GeV

Author

R. Gearhart, Douglas H Beck, Richard G. Milner, M. Epstein, Z. M. Szalata, John Nelson, C. E. Keppel, K. van Bibber, R. D. McKeown, K. P. Coulter, K. Lee, B. Mueller, Wolfgang Lorenzon, Jim Napolitano, H. J. Bulten, P. Bosted, D. J. Margaziotis, Haiyan Gao, P. L. Anthony, A. Lung, H. E. Jackson, S. E. Kuhn, J. F. J. van den Brand, L. H. Tao, R. Ent, J. E. Belz, E. R. Kinney, V. Papavassiliou, Thomas O'Neill, E. J. Beise, J. Arrington, J. O. Hansen, M. Spengos, D. H. Potterveld, G. G. Petratos, C. E. Jones, R. J. Holt, S. E. Rock, Michael Chapman, F. S. Dietrich, Z. E. Meziani, James L. White, Naomi C R Makins, D. F. Geesaman, R. G. Arnold, B. Zeidman, R. E. Segel, B. W. Filippone, Seestrom, S. J., and ZEUS at HERA (IHEF, IoP, FNWI)

Subjects
Physics, Elastic scattering, Nuclear reaction, Quantum chromodynamics, Particle physics, Photon, Hadron, Momentum transfer, Nuclear Theory, General Physics and Astronomy, Nuclear physics, Cross section (physics), Deuterium, Photodisintegration, Neutron, High Energy Physics::Experiment, Nuclear Experiment
Abstract

Measurements were performed for the photodisintegration cross section of the deuteron for photon energies from 1.6 to 2.8 GeV and center-of-mass angles from 37° to 90°. The measured energy dependence of the cross section at θ_(c.m.)=90° is in agreement with the constituent counting rules.

Published
1995

37. Exclusive electron scattering from deuterium at high momentum transfer

Author

P. E. Bosted, M. Spengos, J. Arrington, S. E. Kuhn, M. Epstein, H. J. Bulten, R. Ent, R. D. McKeown, Haiyan Gao, Wolfgang Lorenzon, Z. M. Szalata, J. O. Hansen, B. W. Filippone, Ross Milner, F. S. Dietrich, K. P. Coulter, J. L. White, H. E. Jackson, E. R. Kinney, Thomas O'Neill, B. Mueller, G. G. Petratos, L. H. Tao, P. L. Anthony, J. Nelson, J. F. J. van den Brand, D. H. Potterveld, Kisoo Lee, V. Papavassiliou, Michael Chapman, D. J. Margaziotis, A. Lung, R. Gearhart, S. E. Rock, C. E. Jones, K. van Bibber, E. J. Beise, J. Napolitano, B. Zeidman, E. Belz, D. F. Geesaman, R. G. Arnold, C. E. Keppel, R. J. Holt, Naomi C R Makins, and Other Research IHEF (IoP, FNWI)

Subjects
Physics, Scattering, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Momentum transfer, General Physics and Astronomy, Particle accelerator, Observable, Electron, law.invention, Nuclear physics, Momentum, Deuterium, law, Atomic physics, QUARK EXCHANGE, Nuclear Experiment, Electron scattering, Caltech Library Services
Abstract

Cross sections are presented for the reaction 2H(e,e′p)n for momentum transfers in the range 1.2≤Q^2≤6.8 (GeV/c)^2 and for missing momenta from 0 to 250 MeV/c. The longitudinal-transverse interference structure function has been separated at Q^2 = 1.2 (GeV/c)^2. The observables are compared to calculations performed in nonrelativistic and relativistic frameworks. The data are best described by a fully relativistic calculation.

Published
1995

38. Measurement of the A dependence of deep-inelastic electron scattering

Author

A. T. Katramatou, P. E. Bosted, G. G. Petratos, R. G. Arnold, Arie Bodek, D. J. Sherden, N. Giokaris, A. A. Rahbar, C. C. Chang, S. E. Rock, A. F. Sill, J. Gomez, R. M. Lombard-Nelsen, Z. M. Szalata, and B. Mecking

Subjects
Physics, Nuclear reaction, Cover (topology), Scattering, Center (category theory), Atomic physics, Inelastic scattering, Nucleon, Deep inelastic scattering, Nuclear density
Abstract

Cross sections for deep-inelastic electron scattering from liquid deuterium, gaseous $^{4}\mathrm{He}$, and solid Be, C, Al, Ca, Fe, Ag, and Au targets were measured at the Stanford Linear Accelerator Center using electrons with energies ranging from 8 to 24.5 GeV. These data cover a range in the Bjorken variable $x$ from 0.089 to 0.8, and in momentum transfer ${Q}^{2}$ from 2 to 15 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$. The ratios of cross sections per nucleon ${(\frac{{\ensuremath{\sigma}}^{A}}{{\ensuremath{\sigma}}^{d}})}_{\mathrm{is}}$ for isoscalar nuclei have been extracted from the data. These ratios are greater than unity in the range $0.1lxl0.3$, while for $0.3lxl0.8$ they are less than unity and decrease logarithmically with atomic weight $A$, or linearly with average nuclear density. No ${Q}^{2}$ dependence in the ratios was observed over the kinematic range of the data. These results are compared to various theoretical predictions.

Published
1994

39. Measurement of the Spin-Dependent Structure Function $g_1(x)$ of the Proton

Author

Kwong Lau, A. Witzmann, E. M. Kabuβ, M. D. Corcoran, G. Gracia, H. Postma, N. Horikawa, B. Meyes, R. E. Segel, L. Naumann, J. Saborido, L. S. Pinsky, David Miller, Anne-Laure Martin, Alessandro Bressan, D. von Harrach, R. Kaiser, Drew Parks, Iskender Atilla Reyhancan, C. Fernandez, Patrick Hautle, P. Björkholm, H. J. Kessler, Roland Windmolders, M. Lowe, Yannis K. Semertzidis, J. Pyrlik, A. Arvidson, Massimo Lamanna, Yu. Kisselev, I. Sabo, E. von Goeler, M. Crawford, Mayda Velasco, E. Burtin, Regine Willumeit, F. Marie, L. Betev, R. van Dantzig, U. Stiegler, T. Lindqvist, F. Tessarotto, K. P. Schüler, T. Matsuda, C. Cavata, D. Fasching, D.V. Peshekhonov, M. Litmaath, G. Igo, E. Rondio, Satish Dhawan, Erhan Gülmez, C. Dulya, V. W. Hughes, S. Lopez-Ponte, T. Layda, M. Plo, G. Bardin, Per Berglund, A. Kishi, I.A. Savin, T. Iwata, Ricardo Piegaia, S. Platchkov, J. S. McCarthy, M. Giorgi, J. Cranshaw, Aldo Penzo, M. Grosse Perdekamp, J. Martino, Ulrich Landgraf, J. A. Garzon, Roy Weinstein, N. Shumeiko, Anna Zanetti, Franco Bradamante, Cristino Pérez, A. Rosado, A. Magnon, M. Clocchiatti, Julien Faivre, T. Çuhadar, L. Klostermann, C. A. Heusch, A. de Lesquen, P. Shanahan, T. Gaussiran, R. Seitz, A. Brüll, T. Pussieux, P. Schiavon, M. J. Le Goff, M. Ballintijn, G. van Middelkoop, Tjeerd Ketel, F. Feinstein, J. Lichtenstadt, N. De Groot, T. Hasegawa, G. Baum, C. A. Whitten, B. E. Bonner, S. E. Rock, B. Badelek, K. M. Teichert, I. G. Bird, S. Eichblatt, Matias Rodriguez, Rudiger Voss, N. Hayashi, Gerhard K. Mallot, V. Krivokhijine, Jay Roberts, S. Bültmann, A. Karev, D. Pose, R. Birsa, D. G. Crabb, W. Wislicki, A. Sandacz, A. Steinmetz, F. Perrot-Kunne, T. O. Niinikoski, F. Lehar, Daniel B. Kramer, J. Oberski, A. Staude, N. de Botton, Victor Kukhtin, J. M. Rieubland, A. Nagaitsev, J. Kyynäräinen, Kunikazu Mori, K. Medved, J. H. Moromisato, J. Nassalski, G.I. Smirnov, S. Dalla Torre, B. Frois, F. Sever, J. Vogt, J. Pretz, S. Ishimoto, A. Dyring, E. Arik, Heinrich B. Stuhrmann, D. Adams, J. Zhao, A. Rijllart, Bernardo Adeva, Adams, D., Adeva, B., Arik, E., Arvidson, A., Badelek, B., Ballintijn, M. K., Bardin, G., Baum, G., Berglund, P., Betev, L., Bird, I. G., Birsa, Renato, Björkholm, P., Bonner, B. E., de Botton, N., Bradamante, Franco, Bressan, Andrea, Brüll, A., Bültmann, S., Burtin, E., Cavata, C., Clocchiatti, M., Corcoran, M. D., Crabb, D., Cranshaw, J., Crawford, M., Çuhadar, T., DALLA TORRE, Silvia, van Dantzig, R., Dhawan, S., Dulya, C., Dyring, A., Eichblatt, S., Faivre, J. C., Fasching, D., Feinstein, F., Fernandez, C., Frois, B., Garzon, J. A., Gaussiran, T., Giorgi, Marcello, von Goeler, E., Gracia, G., de Groot, N., Grosse Perdekamp, M., Gülmez, E., von Harrach, D., Hasegawa, T., Hautle, P., Hayashi, N., Heusch, C. A., Horikawa, N., Hughes, V. W., Igo, G., Ishimoto, S., Iwata, T., Kabuß, E. M., Kaiser, R., Karev, A., Kessler, H. J., Ketel, T. J., Kishi, A., Kisselev, Y. u., Klostermann, L., Krämer, D., Krivokhijine, V., Kukhtin, V., Kyynäräinen, J., Lamanna, M., Landgraf, U., Lau, K., Layda, T., Le Goff, M. J., Lehar, F., de Lesquen, A., Lichtenstadt, J., Lindqvist, T., Litmaath, M., Lopez Ponte, S., Lowe, M., Magnon, A., Mallot, G. K., Marie, F., Martin, Anna, Martino, J., Matsuda, T., Meyes, B., Mccarthy, J. S., Medved, K., van Middelkoop, G., Miller, D., Mori, K., Moromisato, J., Nagaitsev, A., Nassalski, J., Naumann, L., Niinikoski, T. O., Oberski, J. E. J., Parks, D. P., Penzo, A., Perez, C., Perrot Kunne, F., Peshekhonov, D., Piegaia, R., Pinsky, L., Platchkov, S., Plo, M., Pose, D., Postma, H., Pretz, J., Pussieux, T., Pyrlik, J., Reyhancan, I., Rieubland, J. M., Rijllart, A., Roberts, J. B., Rock, S., Rodriguez, M., Rondio, E., Rosado, A., Sabo, I., Saborido, J., Sandacz, A., Savin, I., Schiavon, Paolo, Schüler, K. P., Segel, R., Seitz, R., Semertzidis, Y., Sever, F., Shanahan, P., Shumeiko, N., Smirnov, G., Staude, A., Steinmetz, A., Stiegler, U., Stuhrmann, H., Teichert, K. M., Tessarotto, F., Velasco, M., Vogt, J., Voss, R., Weinstein, R., Whitten, C., Windmolders, R., Willumeit, R., Wislicki, W., Witzmann, A., Zanetti, A. M., and Zhao, J.

Subjects
Nuclear and High Energy Physics, Proton, approx. 190 GeV-cms, Hadron, HERA, Nuclear Theory, FOS: Physical sciences, Elementary particle, spin dependence, x-dependence, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), p: polarized target, deep inelastic scattering: muon p, p: structure function, POLARIZED ELECTROPRODUCTION, structure function: moment, NUCLEON, Nuclear Experiment, polarized beam: muon, Spin-½, Physics, BJORKEN SUM-RULE, cross section: asymmetry, High Energy Physics::Phenomenology, Fermion, polarized target: p, dependence: spin, CERN SPS, DEUTERON, magnetic spectrometer: experimental results, sum rule, Baryon, F2, High Energy Physics - Phenomenology, Deuterium, DEEP INELASTIC-SCATTERING, E-P, ASYMMETRY, muon p: deep inelastic scattering, Physics::Accelerator Physics, Phenomenology-HEP, High Energy Physics::Experiment, muon: polarized beam, Atomic physics, Nucleon
Abstract

We have measured the spin-dependent structure function $g_1^p$ of the proton in deep inelastic scattering of polarized muons off polarized protons, in the kinematic range $0.003, Comment: 11 pages, CERN-PPE/94-57

Published
1994

40. Threshold inelastic electron scattering from the proton at high momentum transfers

Author

D. J. Sherden, G. G. Petratos, A. T. Katramatou, C. C. Chang, C. J. Martoff, R. M. Lombard-Nelsen, Lambert Jm, S. E. Rock, J. Gomez, A. A. Rahbar, Z. M. Szalata, A. F. Sill, P. E. Bosted, and R. G. Arnold

Subjects
Nuclear physics, Physics, Proton, Structure function, Inelastic electron scattering, High momentum, Mathematical physics
Abstract

Cross sections for threshold electron scattering from the proton have been measured in the missing mass squared region [ital M][sup 2][lt][ital W][sup 2][lt]2 (GeV)[sup 2] and the four-momentum transfer squared region 6[lt][ital Q][sup 2][lt]30 (GeV/[ital c])[sup 2]. Scaling of the extracted values of the structure function [ital F][sub 2]=[nu][ital W][sub 2] is examined in the variables [ital x], [xi], and [ital W][sup 2]. The best scaling is found for the quantity [ital Q][sup 6][ital F][sub 2], which is found to be linearly proportional to ([ital W][sup 2][minus][ital W][sub th][sup 2]), where [ital W][sub th]=[ital M]+[ital M][sub [pi]].

Published
1994

41. Measurements of elastic electron-proton scattering at large momentum transfer

Author

A. F. Sill, P. E. Bosted, S. E. Rock, J. Gomez, R. G. Arnold, C. C. Chang, R. M. Lombard-Nelsen, A. T. Katramatou, Z. M. Szalata, C. J. Martoff, J. M. Lambert, D. J. Sherden, G. G. Petratos, and A. A. Rahbar

Subjects
Elastic scattering, Quantum chromodynamics, Physics, Proton, Scattering, Quantum mechanics, Magnetic form factor, Momentum transfer, Form factor (quantum field theory), Electron
Abstract

Measurements of the forward-angle differential cross section for elastic electron-proton scattering were made in the range of momentum transfer from [ital Q][sup 2]=2.9 to 31.3 (GeV/[ital c])[sup 2] using an electron beam at the Stanford Linear Accelerator Center. The data span six orders of magnitude in cross section. Combinded statistical and systematic uncertainties in the cross section measurements ranged from 3.6% at low [ital Q][sup 2] to 19% at high [ital Q][sup 2]. These data have been used to extract the proton magnetic form factor [ital G][sub [ital M]][sup [ital p]]([ital Q][sup 2]) and Dirac form factor [ital F][sub 1][sup [ital p]]([ital Q][sup 2]) by using form factor scaling. The logarithmic falloff of [ital Q][sup 4][ital F][sub 1][sup [ital p]] expected from leading twist predictions of perturbative quantum chromodynamics is consistent with the new data at high [ital Q][sup 2]. Some nonperturbative and hybrid calculations also agree with our results.

Published
1993

42. Measurements of transverse electron scattering from the deuteron in the threshold region at high momentum transfers

Author

J. Lichtenstadt, R. S. Hicks, A. Hotta, P. E. Bosted, A. A. Rahbar, K. van Bibber, G. G. Petratos, L. Clogher, M. Frodyma, J. Alster, B. Debebe, J. Lambert, F. S. Dietrich, R. G. Arnold, R. A. Gearhart, A. T. Katramatou, G. A. Peterson, D. Benton, S. E. Rock, G. deChambrier, Z. M. Szalata, and A. Lung

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Transverse plane, Particle physics, Forward angle, Deuterium, Structure function, Quark model, Atomic physics, Electron scattering, High momentum
Abstract

Deuteron electrodisintegration cross sections near 180\ifmmode^\circ\else\textdegree\fi{} have been measured near breakup threshold for the four-momentum transfer squared ${\mathit{Q}}^{2}$ range 1.21--2.76 (GeV/c${)}^{2}$. Evidence for a change of slope in the cross section near ${\mathit{Q}}^{2}$=1 (GeV/c${)}^{2}$ has been obtained. The data are compared to nonrelativistic calculations, which predict a strong influence of meson-exchange currents. The data are also compared to a hybrid quark-hadron model. None of these calculations agrees with the data over the entire measured range of ${\mathit{Q}}^{2}$. The ratio of inelastic structure functions ${\mathit{W}}_{1}$(${\mathit{Q}}^{2}$,${\mathit{E}}_{\mathit{n}\mathit{p}}$)/${\mathit{W}}_{2}$(${\mathit{Q}}^{2}$,${\mathit{E}}_{\mathit{n}\mathit{p}}$) is extracted from the present results and previous forward angle data. No prediction is in good agreement with the deduced ratios at small relative energy ${\mathit{E}}_{\mathit{n}\mathit{p}}$.

Published
1993

43. Study of nuclear effects in the deuteron and extraction of neutron to proton structure function ratio

Author

A. Bodek, S. E. Rock, and S. Dasu

Subjects
Physics, Muon, Proton, Nuclear Theory, High Energy Physics::Phenomenology, EMC effect, Inelastic scattering, Deep inelastic scattering, Nuclear physics, Deuterium, High Energy Physics::Experiment, Neutron, Atomic physics, Neutrino, Nuclear Experiment
Abstract

We performed a combined analysis of electron, muon, neutrino, and anti‐neutrino deep inelastic scattering structure functions of hydrogen and deuterium, within the framework of quark‐parton model. The neutron to proton structure function ratio was obtained using three different techniques: 1) electron and muon scattering experiments on deuterium and hydrogen by using traditional Fermi motion corrections, 2) extrapolation of the EMC effect on heavy targets to deuterium and free nucleons, and 3) using Be and C data. At high x there is a disagreement between these data.

Published
1992

44. Measurements of the deuteron and proton magnetic form factors at large momentum transfers

Author

L. Clogher, A. Hotta, J. Lichtenstadt, R. S. Hicks, A. Lung, B. Debebe, A. A. Rahbar, M. Frodyma, G. deChambrier, J. Alster, K. van Bibber, P. E. Bosted, Z. M. Szalata, R. G. Arnold, F. S. Dietrich, J. Lambert, S. E. Rock, G. G. Petratos, A. T. Katramatou, R. A. Gearhart, G. A. Peterson, and D. Benton

Subjects
Physics, Nuclear and High Energy Physics, Dipole, Particle physics, Proton, Magnetic structure, Magnetic form factor, Isobar, Electron, Nucleon, Wave function
Abstract

Measurements of the deuteron elastic magnetic structure function B(${\mathit{Q}}^{2}$) are reported at squared four-momentum transfer values 1.20\ensuremath{\le}${\mathit{Q}}^{2}$\ensuremath{\le}2.77 (GeV/c${)}^{2}$. Also reported are values for the proton magnetic form factor ${\mathit{G}}_{\mathit{M}\mathit{p}}$(${\mathit{Q}}^{2}$) at 11 ${\mathit{Q}}^{2}$ values between 0.49 and 1.75 (GeV/c${)}^{2}$. The data were obtained using an electron beam of 0.5 to 1.3 GeV. Electrons backscattered near 180\ifmmode^\circ\else\textdegree\fi{} were detected in coincidence with deuterons or protons recoiling near 0\ifmmode^\circ\else\textdegree\fi{} in a large solid-angle double-arm spectrometer system. The data for B(${\mathit{Q}}^{2}$) are found to decrease rapidly from ${\mathit{Q}}^{2}$=1.2 to 2 (GeV/c${)}^{2}$, and then rise to a secondary maximum around ${\mathit{Q}}^{2}$=2.5 (GeV/c${)}^{2}$. Reasonable agreement is found with several different models, including those in the relativistic impulse approximation, nonrelativistic calculations that include meson-exchange currents, isobar configurations, and six-quark configurations, and one calculation based on the Skyrme model. All calculations are very sensitive to the choice of deuteron wave function and nucleon form factor parametrization. The data for ${\mathit{G}}_{\mathit{M}\mathit{p}}$(${\mathit{Q}}^{2}$) are in good agreement with the empirical dipole fit.

Published
1990

45. Measurements of theADependence of Deep-Inelastic Electron Scattering from Nuclei

Author

Z. M. Szalata, A. T. Katramatou, G. G. Petratos, B. Mecking, Peter Bosted, R. M. Lombard, N. Giokaris, D. J. Sherden, A. A. Rahbar, C. C. Chang, S. E. Rock, J. Gomez, A. F. Sill, Arie Bodek, and R. G. Arnold

Subjects
Physics, Nuclear reaction, Mass number, Scattering, General Physics and Astronomy, Charge density, Elementary particle, Atomic physics, Inelastic scattering, Nucleon, Nuclear density
Abstract

The deep-inelastic electron-scattering cross sections per nucleon ${\ensuremath{\sigma}}_{A}$ for D, He, Be, C, A1, Ca, Fe, Ag, and Au were measured in the kinematic range $0.09l~xl~0.9$ and $2l~{Q}^{2}l~15$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$ with use of electrons with energies ranging from 8 to 24.5 GeV. The ratio $\frac{{\ensuremath{\sigma}}_{A}}{{\ensuremath{\sigma}}_{\mathrm{D}}}$ is consistent with unity in the range $0.1lxl0.3$. For $0.3lxl0.8$, the ratio decreases logarithmically with atomic weight $A$, or linearly with average nuclear density. No ${Q}^{2}$ dependence in the ratio was observed over the kinematic range of the data.

Published
1984

46. Measurements of deuteron magnetic form factor high momentum transfer

Author

P. E. Bosted, B. Debebe, R. S. Hicks, J. Alster, J. Lambert, A. T. Katramatou, S. E. Rock, A. Hotta, G. deChambrier, G. G. Petratos, K. van Bibber, A. Lung, L. Clogher, Z. M. Szalata, F. S. Dietrich, M. Frodyma, R. A. Gearhart, G. A. Peterson, D. Benton, R. G. Arnold, A. A. Rahbar, and J. Lichtenstadt

Subjects
Nuclear physics, Momentum, Physics, Elastic scattering, Nuclear reaction, Particle physics, Momentum transfer, Magnetic form factor, Center (category theory), General Physics and Astronomy, Electron, Charged particle
Abstract

The deuteron magnetic form factor B(${Q}^{2}$) has been measured at momentum transfers ${Q}^{2}$=1.21, 1.49, 1.61, 1.74, 1.98, 2.23, 2.48, 2.53, and 2.77 (GeV/c${)}^{2}$ at the Stanford Linear Accelerator Center by detection of electrons backscattered at 180\ifmmode^\circ\else\textdegree\fi{} in coincidence with recoiling deuterons at 0\ifmmode^\circ\else\textdegree\fi{}. The data for B(${Q}^{2}$) are found to decrease rapidly from ${Q}^{2}$=1.2 to 2 (GeV/c${)}^{2}$, then rise to a secondary maximum around ${Q}^{2}$=2.5 (GeV/c${)}^{2}$, in qualitative agreement with impulse-approximation calculations.

Published
1987

47. Precision Measurement ofR=σLσTandF2in Deep-Inelastic Electron Scattering

Author

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

Subjects
Quantum chromodynamics, Baryon, Physics, Nuclear reaction, Particle physics, Scattering, Hadron, General Physics and Astronomy, Elementary particle, Inelastic scattering, Nucleon
Abstract

We report new results on a precision measurement of the ratio $R=\frac{{\ensuremath{\sigma}}_{L}}{{\ensuremath{\sigma}}_{T}}$ and the structure function ${F}_{2}$ for deep-inelastic electron-nucleon scattering in the kinematic range $0.2\ensuremath{\le}x\ensuremath{\le}0.5$ and $1\ensuremath{\le}{Q}^{2}\ensuremath{\le}10$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$. Our results show, for the first time, a clear falloff of $R$ with increasing ${Q}^{2}$. Our $R$ and ${F}_{2}$ results are in good agreement with QCD predictions only when corrections for target-mass effects are included.

Published
1988

48. Precision measurement of R=σL/σT and F2 in deep inelastic electron scattering

Author

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

Subjects
Physics, Quantum chromodynamics, Nuclear and High Energy Physics, Cross section.transverse, Range (particle radiation), Scattering, Structure function, Inelastic electron scattering, Atomic physics, Atomic and Molecular Physics, and Optics
Abstract

We report new results on a precision measurement of the ratio R= σ L / σ T , and the structure function F 2 , for deep inelastic electron-nucleon scattering in the range 0.2≤×≤0.5 and 1≤Q 2 ≤10 (GeV/c) 2 . Our results show, for the first time, a clear falloff of R with increasing Q 2 . Our R and F 2 results are in good agreement with QCD predictions only when corrections for target mass effects are included.

Published
1989

49. Measurement of the Difference inR=σLσTand ofσAσDin Deep-Inelastice−D,e−Fe, ande−AuScattering

Author

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

Subjects
Nuclear physics, Nuclear reaction, Physics, Scattering, EMC effect, General Physics and Astronomy, Sigma, Atomic physics, Inelastic scattering, Nucleon, Deep inelastic scattering, European Muon Collaboration
Abstract

We measured the differences in R=σ_L/σ_T and the cross-section ratio σA/σD in deep-inelastic electron scattering from D, Fe, and Au nuclei in the kinematic range 0.2≤x≤0.5 and 1≤Q^2≤5 (Gev/c)^2. Our results for R^A-R^D are consistent with zero for all x and Q^2, indicating that possible contributions to R from nuclear higher-twist effects and spin-0 constituents in nuclei are not different from those in nucleons. The European Muon Collaboration effect is reconfirmed, and the low-x data from all recent experiments, at all Q^2, are now in agreement.

Published
1988

50. Measurement of the proton elastic form factors for Q2=1−3(Gev/c)2

Author

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

Subjects
Physics, Elastic scattering, Nuclear and High Energy Physics, QCD sum rules, Particle physics, Proton, Scattering, Dirac (software), Perturbative QCD, Diquark, Nuclear physics, symbols.namesake, Pauli exclusion principle, symbols, Nuclear Experiment
Abstract

We report measurements of the proton form factors, G^p_E and G^p_M, extracted from elastic electron scattering in the range 1 ≤ Q^2 ≤ 3 (GeV/c)^2 with uncertainties of

Published
1989

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