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16 results on '"S. K. Nanda"'

1. Measurement of the Target-Normal Single-Spin Asymmetry in Quasielastic Scattering from the ReactionHe3↑(e,e′ )

Author

H. F. Ibrahim, E. Piasetzky, G. D. Cates, Y. Zhang, J. Gomez, Bogdan Wojtsekhowski, S. Frullani, C. Dutta, Chunhui Chen, S. Širca, E. Chudakov, William A. Tobias, R. Subedi, Mustafa Canan, Kalyan Allada, G. Jin, X. Zhan, B. Zhao, S. Golge, R. Michaels, X. Zheng, B. Schoenrock, P. Monaghan, B. D. Anderson, O. Glamazdin, Olfred Hansen, J. R. M. Annand, A. Saha, F. Garibaldi, S. K. Nanda, H. P. Khanal, Yujie Qiang, Andrew Puckett, M. H. Shabestari, Pete Markowitz, H. Kang, C. Ayerbe-Gayoso, Z. Ye, M. Posik, B. E. Norum, W. Luo, Rocco Schiavilla, Diana Parno, X. Deng, P. C. Bradshaw, X. Jiang, B. Sawatzky, Yingxiao Wang, Xin Qian, R. De Leo, G. M. Urciuoli, N. Muangma, T. Holmstrom, L. Y. Zhu, Shalev Gilad, Yiyang Zhang, C. W. de Jager, Haiyan Gao, J. P. Chen, L. El Fassi, W. U. Boeglin, Joseph M. Katich, J. Huang, S. Riordan, E. Long, Douglas Higinbotham, M. K. Jones, X. Qiu, M. Mihovilovič, E. Jensen, J. St. John, B. Moffit, Wolfgang Korsch, W. Tireman, K. Pan, K. Wang, A. Deur, P. M. King, Guy Ron, D. Wang, Ronald Gilman, J. W. Watson, V. A. Punjabi, A. Shahinyan, M. Meziane, A. Camsonne, H.-J. Lu, Vincent Sulkosky, T. Averett, R. A. Lindgren, J. J. LeRose, and D. Flay

Subjects
Physics, Quasielastic scattering, Particle physics, Scattering, media_common.quotation_subject, General Physics and Astronomy, Parton, Polarization (waves), Asymmetry, Nuclear physics, High Energy Physics::Experiment, Neutron, Nuclear Experiment, Nucleon, Lepton, media_common
Abstract

We report the first measurement of the target single-spin asymmetry, A(y), in quasielastic scattering from the inclusive reaction (3)He(↑)(e,e') on a (3)He gas target polarized normal to the lepton scattering plane. Assuming time-reversal invariance, this asymmetry is strictly zero for one-photon exchange. A nonzero A(y) can arise from the interference between the one- and two-photon exchange processes which is sensitive to the details of the substructure of the nucleon. An experiment recently completed at Jefferson Lab yielded asymmetries with high statistical precision at Q(2)=0.13, 0.46, and 0.97 GeV(2). These measurements demonstrate, for the first time, that the (3)He asymmetry is clearly nonzero and negative at the 4σ-9σ level. Using measured proton-to-(3)He cross-section ratios and the effective polarization approximation, neutron asymmetries of -(1-3)% were obtained. The neutron asymmetry at high Q(2) is related to moments of the generalized parton distributions (GPDs). Our measured neutron asymmetry at Q(2)=0.97 GeV(2) agrees well with a prediction based on two-photon exchange using a GPD model and thus provides a new, independent constraint on these distributions.

Published
2015

2. Measurement of Double-Polarization Asymmetries in the QuasielasticHe→3(e→,e′d)Process

Author

P. U. Sauer, M. Viviani, V. A. Punjabi, T. Averett, W. Tireman, P. M. King, Bogdan Wojtsekhowski, Yiyang Zhang, M. H. Shabestari, C. Dutta, William A. Tobias, F. Garibaldi, H. P. Khanal, Joseph M. Katich, A. Shahinyan, Simon Širca, R. Skibiński, Mustafa Canan, H. Kang, Kalyan Allada, B. D. Anderson, M. Mihovilovic, Z. Ye, Douglas Higinbotham, A. Deltuva, A. Deur, M. K. Jones, B. E. Norum, G. D. Cates, X. Deng, E. Jensen, Y. Zhang, Yingxiao Wang, Wolfgang Korsch, K. Pan, X. Jiang, Henryk Witała, L. E. Marcucci, K. Wang, L. Y. Zhu, G. M. Urciuoli, Xin Qian, N. Muangma, Shalev Gilad, C. W. de Jager, J. St. John, S. Riordan, X. Zhan, B. Moffit, A. Kievsky, B. Schoenrock, S. Golge, H. F. Ibrahim, L. El Fassi, W. U. Boeglin, Diana Parno, E. Long, J. Watson, D. Wang, E. Chudakov, Pete Markowitz, Ronald Gilman, R. A. Lindgren, J. J. LeRose, O. Glamazdin, R. De Leo, Olfred Hansen, J. R. M. Annand, G. Jin, J. P. Chen, W. Luo, X. Zheng, Haiyan Gao, B. Zhao, S. K. Nanda, J. Huang, Yujie Qiang, Andrew Puckett, J. Gomez, P. Monaghan, Rocco Schiavilla, D. Flay, B. Sawatzky, M. Meziane, A. Camsonne, T. Holmstrom, H.-J. Lu, Vincent Sulkosky, Jacek Golak, X. Qui, R. Michaels, M. Posik, E. Piasetzky, S. Frullani, R. Subedi, Arijit Saha, Chunhui Chen, and P. C. Bradshaw

Subjects
Nuclear physics, Physics, Scattering, Hadron, General Physics and Astronomy, Electron, Kinematics, Few-body systems, Functional dependency, Polarization (waves), Omega
Abstract

We present a precise measurement of double-polarization asymmetries in the 3He(e,e'd) reaction. This particular process is a uniquely sensitive probe of hadron dynamics in 3He and the structure of the underlying electromagnetic currents. The measurements have been performed in and around quasi-elastic kinematics at Q2=0.25(GeV/c)2 for missing momenta up to 270MeV/c. The asymmetries are in fair agreement with the state-of-the-art calculations in terms of their functional dependencies on pm and omega, but are systematically offset. Beyond the region of the quasi-elastic peak, the discrepancies become even more pronounced. Thus, our measurements have been able to reveal deficiencies in the most sophisticated calculations of the three-body nuclear system, and indicate that further refinement in the treatment of their two- and/or three-body dynamics is required.

Published
2014

3. Measurement of the Target-Normal Single-Spin Asymmetry in Deep-Inelastic Scattering from the Reaction He3↑(e,e′)X

Author

W. Chen, S. Marrone, M. Osipenko, A. Kolarkar, Salvatore Frullani, Nilanga Liyanage, D. J. Margaziotis, E. Cisbani, T. Averett, M. Huang, X. Jiang, L. Guo, E. Long, Y. X. Ye, Wouter Deconinck, G. Jin, Bogdan Wojtsekhowski, H. Yao, X. Zheng, R. Subedi, F. Cusanno, A. Kelleher, S. K. Nanda, Yujie Qiang, William Bertozzi, X. Yan, Ronald Ransome, David Hamilton, Fatiha Benmokhtar, C. Dutta, Pete Markowitz, Xin Qian, M. H. Shabestari, P. A. M. Dolph, L. El Fassi, L. Zhu, R. De Leo, X. Deng, J. C. Cornejo, L. G. Tang, Yingxiao Wang, J. P. Chen, W. Kim, Shalev Gilad, D. McNulty, C. W. de Jager, K. A. Aniol, J. Huang, G. M. Urciuoli, Chunhui Chen, X. Zhan, Diana Parno, S. K. Phillips, X. Li, B. Moffit, Mauro Iodice, Wolfgang Korsch, Franco Garibaldi, S. S. Stepanyan, Simon Širca, Mustafa Canan, Kalyan Allada, Xiaofeng Zhu, A. Shahinyan, M. Posik, X. Zong, A. J. R. Puckett, Y. Li, P. Bosted, Z. E. Meziani, R. A. Lindgren, J. J. LeRose, A. Saha, M. M. Dalton, Jen-Chieh Peng, B. Sawatzky, Young Do Oh, I. Vilardi, H. Ding, P. C. Bradshaw, S. Riordan, L. Yuan, T. Holmstrom, H. F. Ibrahim, K. Chirapatpimol, Dipangkar Dutta, A. Camsonne, E. Chudakov, Vincent Sulkosky, A. Deur, R. Michaels, C. Muñoz Camacho, B. Zhao, Adam M. Tobias, G. D. Cates, Douglas Higinbotham, Yong Zhang, M. K. Jones, E. Schulte, O. Glamazdin, Vladimir Nelyubin, Olfred Hansen, J. R. M. Annand, K. Wang, Abdurahim Rakhman, Y. Zhang, Haiyan Gao, Amrendra Narayan, Joseph M. Katich, D. Gaskell, S. Golge, H. J. Lu, Ronald Gilman, Z. Ye, B. E. Norum, and Y. Zhao

Subjects
Physics, Range (particle radiation), Scattering, media_common.quotation_subject, General Physics and Astronomy, Deep inelastic scattering, Asymmetry, Nuclear physics, Cathode ray, High Energy Physics::Experiment, Born approximation, Nuclear Experiment, media_common, Sign (mathematics), Spin-½
Abstract

We report the first measurement of the target-normal single-spin asymmetry in deep-inelastic scattering from the inclusive reaction ^3He^↑ (e,e′) X on a polarized ^3He gas target. Assuming time-reversal invariance, this asymmetry is strictly zero in the Born approximation but can be nonzero if two-photon-exchange contributions are included. The experiment, conducted at Jefferson Lab using a 5.89 GeV electron beam, covers a range of 1.7 2 GeV, which is nonzero at the 2.89σ level. Our measured asymmetry agrees both in sign and magnitude with a two-photon-exchange model prediction that uses input from the Sivers transverse momentum distribution obtained from semi-inclusive deep-inelastic scattering.

Published
2014

4. Precision Measurement of the Neutron Twist-3 Matrix Elementd2n: Probing Color Forces

Author

H. F. Ibrahim, T. Averett, C. E. Hyde, B. Zhao, V. Mamyan, E. Chudakov, Bogdan Wojtsekhowski, F. Cusanno, Fatiha Benmokhtar, Whitney Armstrong, R. Michaels, A. Kolarkar, S. Choi, Y. Zhang, X. Yan, Xin Qian, Mustafa Canan, G. D. Cates, Kalyan Allada, Yiyang Zhang, Amrendra Narayan, Joseph M. Katich, G. B. Franklin, Young Do Oh, W. Troth, A. Saha, N. Muangma, Wouter Deconinck, A. Shahinyan, T. Holmstrom, M. Mihovilovic, M. H. Shabestari, Haiyan Gao, D. Wang, G. Jin, X. Zheng, R. A. Lindgren, L. Guo, J. J. LeRose, R. Subedi, Ronald Gilman, H. Yao, E. Long, S. Golge, M. Posik, X. Deng, Wolfgang Korsch, Douglas Higinbotham, A. Kelleher, M. Friend, S. K. Nanda, Yujie Qiang, X. Jiang, D. Flay, Y. X. Ye, P. Solvignon, D. McNulty, G. Kumbartzki, Nuruzzaman, Z. E. Meziani, Simon Širca, Chunhui Chen, F. Garibaldi, B. Moffit, B. Sawatzky, A. Deur, Yingxiao Wang, O. Glamazdin, Olfred Hansen, A. Camsonne, Z. Ye, B. E. Norum, Vincent Sulkosky, J. Gomez, Shalev Gilad, Jen-Chieh Peng, X. Zhan, L. Yuan, C. W. de Jager, Diana Parno, C. Dutta, William A. Tobias, J. P. Chen, J. Huang, A. Lukhanin, William Bertozzi, L. El Fassi, Nilanga Liyanage, Abdurahim Rakhman, Vladimir Nelyubin, M. M. Dalton, and S. Riordan

Subjects
Physics, Scattering, General Physics and Astronomy, High Energy Physics::Experiment, Neutron, Electron, Lattice QCD, Atomic physics, Spin structure, Deep inelastic scattering, Resonance (particle physics), Beam (structure)
Abstract

Double-spin asymmetries and absolute cross sections were measured at large Bjorken x (0.25≤x≤0.90), in both the deep-inelastic and resonance regions, by scattering longitudinally polarized electrons at beam energies of 4.7 and 5.9 GeV from a transversely and longitudinally polarized ^3He target. In this dedicated experiment, the spin structure function g^3He_2 was determined with precision at large x, and the neutron twist-3 matrix element dn2 was measured at ⟨Q2⟩ of 3.21 and 4.32 GeV^2/c^2, with an absolute precision of about 10^(−5). Our results are found to be in agreement with lattice QCD calculations and resolve the disagreement found with previous data at ⟨Q^2⟩=5 GeV^2/c^2. Combining d^n_2 and a newly extracted twist-4 matrix element f^n_2, the average neutron color electric and magnetic forces were extracted and found to be of opposite sign and about 30 MeV/fm in magnitude.

Published
2014

5. GEp/GMpRatio by Polarization Transfer ine→p→ep→

Author

M. K. Jones, K. A. Aniol, F. T. Baker, J. Berthot, P. Y. Bertin, W. Bertozzi, A. Besson, L. Bimbot, W. U. Boeglin, E. J. Brash, D. Brown, J. R. Calarco, L. S. Cardman, C.-C. Chang, J.-P. Chen, E. Chudakov, S. Churchwell, E. Cisbani, D. S. Dale, R. De Leo, A. Deur, B. Diederich, J. J. Domingo, M. B. Epstein, L. A. Ewell, K. G. Fissum, A. Fleck, H. Fonvieille, S. Frullani, J. Gao, F. Garibaldi, A. Gasparian, G. Gerstner, S. Gilad, R. Gilman, A. Glamazdin, C. Glashausser, J. Gomez, V. Gorbenko, A. Green, J.-O. Hansen, C. R. Howell, G. M. Huber, M. Iodice, C. W. de Jager, S. Jaminion, X. Jiang, W. Kahl, J. J. Kelly, M. Khayat, L. H. Kramer, G. Kumbartzki, M. Kuss, E. Lakuriki, G. Lavessière, J. J. LeRose, M. Liang, R. A. Lindgren, N. Liyanage, G. J. Lolos, R. Macri, R. Madey, S. Malov, D. J. Margaziotis, P. Markowitz, K. McCormick, J. I. McIntyre, R. L. J. van der Meer, R. Michaels, B. D. Milbrath, J. Y. Mougey, S. K. Nanda, E. A. J. M. Offermann, Z. Papandreou, C. F. Perdrisat, G. G. Petratos, N. M. Piskunov, R. I. Pomatsalyuk, D. L. Prout, V. Punjabi, G. Quéméner, R. D. Ransome, B. A. Raue, Y. Roblin, R. Roche, G. Rutledge, P. M. Rutt, A. Saha, T. Saito, A. J. Sarty, T. P. Smith, P. Sorokin, S. Strauch, R. Suleiman, K. Takahashi, J. A. Templon, L. Todor, P. E. Ulmer, G. M. Urciuoli, P. Vernin, B. Vlahovic, H. Voskanyan, K. Wijesooriya, B. B. Wojtsekhowski, R. J. Woo, F. Xiong, G. D. Zainea, and Z.-L. Zhou

Subjects
Elastic scattering, Physics, Proton, 010308 nuclear & particles physics, Proton magnetic moment, General Physics and Astronomy, Electron, Polarization (waves), 01 natural sciences, Charged particle, Nuclear physics, Magnetization, 0103 physical sciences, Magnetic form factor, Physics::Accelerator Physics, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

The ratio of the proton's elastic electromagnetic form factors was obtained by measuring the transverse and longitudinal polarizations of recoiling protons from the elastic scattering of polarized electrons with unpolarized protons. The ratio of the electric to magnetic form factor is proportional to the ratio of the transverse to longitudinal recoil polarizations. The ratio was measured over a range of four-momentum transfer squared between 0.5 and 3.5 GeV-squared. Simultaneous measurement of transverse and longitudinal polarizations in a polarimeter provides good control of the systematic uncertainty. The results for the ratio of the proton's electric to magnetic form factors show a systematic decrease with increasing four momentum squared, indicating for the first time a marked difference in the spatial distribution of charge and magnetization currents in the proton.

Published
2000

6. Beam-Target Double-Spin AsymmetryALTin Charged Pion Production from Deep Inelastic Scattering on a Transversely PolarizedHe3Target at1.4<Q2<2.7 GeV2

Author

Jen-Chieh Peng, Wolfgang Korsch, L. Yuan, L. G. Tang, Nilanga Liyanage, K. Chirapatpimol, S. K. Nanda, Yujie Qiang, A. Shahinyan, Z. E. Meziani, H. J. Lu, X. Yan, Salvatore Frullani, Y. Li, D. J. Margaziotis, E. Cisbani, R. A. Lindgren, J. J. LeRose, A. Deur, L. Guo, E. Long, B. Zhao, X. Zhan, Ronald Gilman, I. Vilardi, H. Ding, Wouter Deconinck, A. Kelleher, G. Jin, R. Subedi, Diana Parno, X. Zheng, Bogdan Wojtsekhowski, Ronald Ransome, P. Bosted, Z. Ye, B. E. Norum, Xin Qian, Y. Zhang, W. Kim, Franco Garibaldi, B. Sawatzky, P. A. M. Dolph, Simon Širca, R. Michaels, J. C. Cornejo, C. Dutta, W. Chen, Douglas Higinbotham, M. K. Jones, B. Moffit, A. Camsonne, F. Cusanno, Vincent Sulkosky, X. Zong, A. J. R. Puckett, L. El Fassi, Xiaofeng Zhu, S. Golge, X. Li, C. Muñoz Camacho, K. Wang, Yingxiao Wang, M. Huang, G. D. Cates, M. Posik, Shalev Gilad, C. W. de Jager, X. Jiang, K. A. Aniol, M. H. Shabestari, M. Osipenko, Mauro Iodice, Y. X. Ye, William Bertozzi, H. F. Ibrahim, S. Marrone, Amrendra Narayan, Joseph M. Katich, D. Gaskell, David Hamilton, Pete Markowitz, Dipangkar Dutta, X. Deng, R. De Leo, J. P. Chen, S. S. Stepanyan, Mustafa Canan, Chen Chen, Kalyan Allada, T. Holmstrom, D. McNulty, E. Chudakov, T. Averett, J. Huang, G. M. Urciuoli, Young Do Oh, A. Tobias, Fatiha Benmokhtar, Abdurahim Rakhman, A. Kolarkar, M. M. Dalton, S. Riordan, A. Saha, Yong Zhang, Vladimir Nelyubin, Haiyan Gao, P. C. Bradshaw, S. K. Phillips, O. Glamazdin, Olfred Hansen, J. R. M. Annand, L. Y. Zhu, E. Schulte, and H. Yao

Subjects
Quark, Physics, Particle physics, 010308 nuclear & particles physics, Scattering, media_common.quotation_subject, General Physics and Astronomy, Parton, Electron, Deep inelastic scattering, 01 natural sciences, Asymmetry, Nuclear physics, Pion, 0103 physical sciences, High Energy Physics::Experiment, Neutron, Nuclear Experiment, 010306 general physics, media_common
Abstract

We report the first measurement of the double-spin asymmetry A_(LT) for charged pion electroproduction in semi-inclusive deep-inelastic electron scattering on a transversely polarized ^3He target. The kinematics focused on the valence quark region, 0.16

Published
2012

7. Single Spin Asymmetries in Charged Pion Production from Semi-Inclusive Deep Inelastic Scattering on a Transversely PolarizedHe3Target atQ2=1.4–2.7 GeV2

Author

A. Kolarkar, M. Huang, X. Jiang, C. Dutta, M. Osipenko, T. Averett, H. Yao, W. Chen, Abdurahim Rakhman, L. G. Tang, Bogdan Wojtsekhowski, Y. X. Ye, X. Zhan, X. Yan, O. Glamazdin, Olfred Hansen, J. R. M. Annand, Fatiha Benmokhtar, D. McNulty, Arijit Saha, Diana Parno, W. Kim, Nilanga Liyanage, Wouter Deconinck, R. Subedi, D. J. Margaziotis, Salvatore Frullani, Chunhui Chen, P. Bosted, Yingxiao Wang, Yong Zhang, Shalev Gilad, Vladimir Nelyubin, Wolfgang Korsch, M. M. Dalton, Yuxiang Zhao, E. Cisbani, C. W. de Jager, K. A. Aniol, L. Guo, S. Riordan, E. Long, L. Y. Zhu, M. H. Shabestari, A. Kelleher, X. Li, S. K. Phillips, Mauro Iodice, E. Schulte, J. P. Chen, X. Deng, A. Shahinyan, G. Jin, X. Zheng, J. Huang, G. M. Urciuoli, S. K. Nanda, P. A. M. Dolph, Yujie Qiang, J. C. Cornejo, A. Tobias, William Bertozzi, S. Marrone, David Hamilton, Pete Markowitz, R. De Leo, Franco Garibaldi, Simon Širca, Ronald Ransome, S. S. Stepanyan, Xin Qian, Mustafa Canan, Kalyan Allada, B. Moffit, L. El Fassi, Xiaofeng Zhu, Z. E. Meziani, R. A. Lindgren, J. J. LeRose, I. Vilardi, H. Ding, B. Sawatzky, G. D. Cates, A. Camsonne, Vincent Sulkosky, Y. Li, X. Zong, R. Michaels, H. F. Ibrahim, C. Muñoz Camacho, Dipangkar Dutta, B. Zhao, A. J. R. Puckett, Haiyan Gao, E. Chudakov, T. Holmstrom, Young Do Oh, F. Cusanno, Douglas Higinbotham, M. K. Jones, A. Deur, M. Posik, P. C. Bradshaw, K. Wang, H. J. Lu, Jen-Chieh Peng, Ronald Gilman, L. Yuan, K. Chirapatpimol, Z. Ye, B. E. Norum, Y. Zhang, Amrendra Narayan, Joseph M. Katich, D. Gaskell, and S. Golge

Subjects
Physics, Particle physics, Proton, 010308 nuclear & particles physics, Hadron, General Physics and Astronomy, Inelastic scattering, Deep inelastic scattering, 01 natural sciences, Baryon, Nuclear physics, Pion, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Nucleon, Lepton
Abstract

We report the first measurement of target single spin asymmetries in the semi-inclusive ^3He(e,e^′π^±)X reaction on a transversely polarized target. The experiment, conducted at Jefferson Lab using a 5.9 GeV electron beam, covers a range of 0.16

Published
2011

8. High-Resolution Spectroscopy ofNΛ16by Electroproduction

Author

P. E. Ulmer, B. Kross, Maryam Moteabbed, J. Reinhold, R. Roche, Pavlo Baturin, H. Benaoum, H. F. Ibrahim, E. Voutier, Toshinobu Miyoshi, Bogdan Wojtsekhowski, B. Craver, E. Chudakov, P. Ambrozewicz, J. P. Chen, F. Giuliani, P.Y. Bertin, Y. Okasyasu, Olivier Gayou, S. K. Nanda, F. Cusanno, D. Hayes, C. E. Hyde, Yujie Qiang, P. E. Reimer, A. Deur, K. I. Blomqvist, M. Sotona, W. U. Boeglin, T. Holmstrom, G. M. Urciuoli, P. Solvignon, Kent Paschke, Alexandre Camsonne, P. Monaghan, L. J. Kaufman, H. Breuer, C. F. Perdrisat, S. Marrone, Eugenio Nappi, A. Acha, R. Michaels, C. Zorn, K. Kino, D. J. Margaziotis, L. Lagamba, C. Munoz Camacho, Pete Markowitz, E. Folts, A. J. Sarty, S. Frullani, Vladimir Nelyubin, D. J. Millener, A. Saha, M. Gricia, R. De Leo, Brian Raue, Simon Širca, M. Lucentini, F. Garibaldi, Tohru Suzuki, J. Segal, E. Cisbani, Mauro Iodice, P. Bydzovsky, H. Ueno, R. Fratoni, B. Reitz, Douglas Higinbotham, J. Gomez, R. Snyder, X. Jiang, X. Zeng, C. W. de Jager, R. J. Feuerbach, P. Veneroni, E. Piasetzky, C. Ferdi, K. A. Aniol, Bryan J. Moffit, Jaideep Singh, Seonho Choi, K. McCormick, R. Subedi, R. A. Lindgren, J. J. LeRose, V. Sulkosky, L. Coman, J.-O. Hansen, B. E. Norum, C. C. Chang, Z. E. Meziani, P. Brindza, V. A. Punjabi, G. de Cataldo, A. Shahinyan, F. Santavenere, S. Colilli, and V. M. Rodriguez

Subjects
Physics, 010308 nuclear & particles physics, Binding energy, General Physics and Astronomy, Sigma, Halo nucleus, Lambda, Hypernucleus, 01 natural sciences, 0103 physical sciences, Atomic physics, Thin film, 010306 general physics, Spectroscopy, Energy (signal processing)
Abstract

An experimental study of the 16O(e,e'K^+)16N_Lambda reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e,e'K^+)Lambda,Sigma_0 exclusive reactions and a precise calibration of the energy scale. A ground-state binding energy of 13.76 +/- 0.16 MeV was obtained for 16N_Lambda with better precision than previous measurements on the mirror hypernucleus 16O_Lambda. Precise energies have been determined for peaks arising from a Lambda in s and p orbits coupled to the p_{1/2} and p_{3/2} hole states of the 15N core nucleus.

Published
2009

9. Investigation of Proton-Proton Short-Range Correlations via theC12(e,e′pp)Reaction

Author

Yujie Qiang, Eli Piasetzky, P. Monaghan, William Bertozzi, B. Craver, H. Benaoum, H. F. Ibrahim, Pete Markowitz, N. Thompson, A. Shahinyan, B. D. Anderson, G. J. Kumbartzki, Bogdan Wojtsekhowski, G. Rosner, E. Chudakov, B. Sawatzky, H. Yao, J. O. Hansen, V. Sulkosky, P.Y. Bertin, R. Michaels, O. Glamazdin, John Arrington, L. Zhu, J. P. Chen, S. Frullani, J. Gomez, G. M. Urciuoli, Simon Širca, F. Garibaldi, A. Saha, P. Solvignon, A. Kelleher, L. J. Kaufman, S. A. Wood, T. Holmstrom, J. Reinhold, Olivier Gayou, Jrm Annand, D. J. Margaziotis, Guy Ron, S. Marrone, Shalev Gilad, R. Shneor, Larry Weinstein, P. E. Ulmer, Karl Slifer, A. Kolarkar, C. W. de Jager, M. Potokar, K. A. Aniol, E. Cisbani, E. Kuchina, R. J. Feuerbach, R. A. Lindgren, J. J. LeRose, J. W. Watson, Bryan J. Moffit, X. Zheng, V. A. Punjabi, D. G. Meekins, Fatiha Benmokhtar, R. Subedi, E. Voutier, C. F. Perdrisat, W. U. Boeglin, R. Igarashi, Nilanga Liyanage, Y. Jiang, Douglas Higinbotham, E. Jans, K. Wang, Seonho Choi, Ronald Gilman, B. Reitz, M. Mazouz, X. Jiang, and S. K. Nanda

Subjects
Nuclear reaction, Physics, Proton, 010308 nuclear & particles physics, Nuclear Theory, Hadron, Strong interaction, General Physics and Astronomy, 01 natural sciences, Baryon, Momentum, Nuclear physics, 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Lepton
Abstract

In this work we present a simultaneous measurement of the 12C(e,e'p) and 12C(e,e'pp) reactions. This measurement was done as part of the E01-015 experiment at Hall A of Jefferson Lab, at Q2 = 2 (GeV/c) 2 , xB = 1.2, for an (e,e'p) missing-momentum range from 300 to 600 MeV/c. At these kinematics conditions, with a missing-momentum greater than the Fermi momentum of nucleons in a nucleus and far from the D excitation, nucleon-nucleon Short-Range Correlations (SRCs) are predicted to dominate the reaction. For 9.5 ± 2% of the 12C(e,e2p) events, a recoiling partner proton was observed in the opposite direction to the 12C(e,e2p) missing momentum vector with roughly equal momentum. This observation is an experimental signature for proton-proton short-range correlations (pp-SRC) in nuclei. Even though the probability of pp-SRCs in nuclei is small, they are important since they can teach us about the strong interaction at short distances. Moreover, as a manifestation of asymmetric

Published
2007

10. High Resolution Spectroscopy ofBΛ12by Electroproduction

Author

G. M. Urciuoli, D. J. Margaziotis, P.Y. Bertin, S. Colilli, Y. Okasyasu, L. Lagamba, P. Monaghan, G. de Cataldo, Pavlo Baturin, B. Craver, E. Piasetzky, C. Zorn, M. Gricia, H. Breuer, D. J. Millener, J. Gomez, K. Kino, P. Bydžovský, Z. E. Meziani, E. Cisbani, H. Ueno, T. Miyoshi, R. Michaels, Brian Raue, L. Coman, P. E. Reimer, P. E. Ulmer, V. Nelyubin, B. Reitz, P. Brindza, H. Benaoum, H. F. Ibrahim, M. Iodice, C. Munoz Camacho, E. Folts, Olivier Gayou, R. A. Lindgren, J. J. LeRose, Kent Paschke, R. Snyder, S. Marrone, R. J. Feuerbach, B. E. Norum, P. Veneroni, R. Roche, A. Shahinyan, V. A. Punjabi, A. Acha, C. W. de Jager, E. Chudakov, Bogdan Wojtsekhowski, K. A. Aniol, Bryan J. Moffit, W. U. Boeglin, V. Sulkosky, P. Ambrozewicz, J. O. Hansen, V. M. Rodriguez, F. Giulani, A. Saha, Tohru Suzuki, X. Jiang, C. Ferdi, K. I. Blomqvist, Maryam Moteabbed, T. Holmstrom, Franco Garibaldi, Y. X. Ye, C. C. Chang, R. Subedi, R. Fratoni, Simon Širca, C. F. Perdrisat, Pete Markowitz, R. De Leo, Salvatore Frullani, A. J. Sarty, L. J. Kaufman, F. Cusanno, Jaideep Singh, A. Deur, F. Santavenere, Seonho Choi, J. Segal, K. McCormick, A. Camsonne, Douglas Higinbotham, E. Voutier, S. Zhou, P. Solvignon, M. Sotona, X. Zheng, Charles Hyde, S. K. Nanda, Yujie Qiang, Eugenio Nappi, D. Hayes, B. Kross, J. Reinhold, M. Lucentini, and J. P. Chen

Subjects
Physics, Superconductivity, 010308 nuclear & particles physics, Resolution (electron density), General Physics and Astronomy, Order (ring theory), Lambda, 01 natural sciences, Ring-imaging Cherenkov detector, Nuclear physics, Full width at half maximum, 0103 physical sciences, Nuclear Experiment, 010306 general physics, Spectroscopy, Energy (signal processing)
Abstract

An experiment measuring electroproduction of hypernuclei has been performed in Hall A at Jefferson Lab on a $^{12}$C target. In order to increase counting rates and provide unambiguous kaon identification two superconducting septum magnets and a Ring Imaging CHerenkov detector (RICH) were added to the Hall A standard equipment. An unprecedented energy resolution of less than 700 keV FWHM has been achieved. Thus, the observed \lam{12}{B} spectrum shows for the first time identifiable strength in the core-excited region between the ground-state {\it s}-wave $\Lambda$ peak and the 11 MeV {\it p}-wave $\Lambda$ peak.

Published
2007

11. Precision Measurements of the Nucleon Strange Form Factors atQ2∼0.1 GeV2

Author

S. K. Nanda, Yujie Qiang, V. Ziskin, R. Michaels, J. P. Chen, J. M. Finn, M. Stutzman, T. Averett, Z. E. Meziani, Nilanga Liyanage, L. Lagamba, P. M. King, G. M. Urciuoli, X. Jiang, R. I. Pomatsalyuk, John Arrington, Richard Wilson, J. Hansknecht, S. Kowalski, B. Craver, S. K. Phillips, Ronald Gilman, R. Holmes, D. J. Margaziotis, J. Barber, R. Snyder, D. Lhuillier, Kent Paschke, A. J. R. Puckett, S. Širca, J. Roche, A. Acha, R. Subedi, Pete Markowitz, R. De Leo, M. Poelker, C. W. de Jager, K. A. Aniol, Bryan J. Moffit, L. J. Kaufman, Douglas Higinbotham, F. Cusanno, A. Saha, T. Holmstrom, A. Kolarkar, M. Potokar, A. Deur, Lindsay Glesener, S. Zhou, R. A. Lindgren, Bogdan Wojtsekhowski, K. Wang, K. Otis, J. J. LeRose, V. Nelyubin, S. Frullani, Peter S. LaViolette, S. L. Bailey, B. Reitz, Jaideep Singh, H. Yao, E. Cisbani, Paul Souder, D. S. Armstrong, X. Zheng, K. Fuoti, Joseph M. Katich, F. Butaru, R. J. Feuerbach, P. Solvignon, A. Kelleher, V. Sulkosky, Xin Qian, Y. C. Chao, X. Zhan, J. Grames, A. Beck, E. Kuchina, B. Sawatzky, D. G. Meekins, K. S. Kumar, K. Grimm, A. Whitbeck, Y. X. Ye, P. Bosted, E. Burtin, William A. Tobias, P. Decowski, P. E. Ulmer, R. Suleiman, Y. Prok, S. Fuchs, G. D. Cates, P.Y. Bertin, H. Benaoum, H. F. Ibrahim, J. Benesch, E. Chudakov, J. O. Hansen, and Karl Slifer

Subjects
Quark, Elastic scattering, Physics, Particle physics, Strange quark, 010308 nuclear & particles physics, Hadron, General Physics and Astronomy, Elementary particle, Strangeness, 7. Clean energy, 01 natural sciences, Nuclear physics, Baryon, 0103 physical sciences, 010306 general physics, Nucleon
Abstract

We report new measurements of the parity-violating asymmetry A_PV in elastic scattering of 3 GeV electrons off hydrogen and 4He targets with ~6.0 degrees. The 4He result is A_PV = (+6.40 +/- 0.23 (stat) +/- 0.12 (syst)) x10^-6. The hydrogen result is A_PV = (-1.58 +/- 0.12 (stat) +/- 0.04 (syst)) x10^-6. These results significantly improve constraints on the electric and magnetic strange form factors G_E^s and G_M^s. We extract G_E^s = 0.002 +/- 0.014 +/- 0.007 at = 0.077 GeV^2, and G_E^s + 0.09 G_M^s = 0.007 +/- 0.011 +/- 0.006 at = 0.109 GeV^2, providing new limits on the role of strange quarks in the nucleon charge and magnetization distributions.

Published
2007

12. Scaling Tests of the Cross Section for Deeply Virtual Compton Scattering

Author

Z. E. Meziani, F. Sabatié, Ronald Gilman, K. McCormick, P. Monaghan, H. Benaoum, H. F. Ibrahim, G. Laveissière, R. Subedi, Bogdan Wojtsekhowski, R. Michaels, Paul Gueye, R. A. Lindgren, B. Michel, V. Sulkosky, D. Hayes, M. Brossard, J.-M. Fieschi, C. W. de Jager, K. A. Aniol, C. Munoz Camacho, Olivier Gayou, B. Craver, Bryan J. Moffit, M. Beaumel, B. Guillon, Douglas Higinbotham, E. Chudakov, D. J. Margaziotis, M. Amarian, G. Gavalian, T. Holmstrom, Y. Roblin, X. Jiang, K. Wang, M. Mazouz, Arijit Saha, G. J. Kumbartzki, P. A. M. Guichon, Ronald Ransome, A. Kolarkar, B. Reitz, H. S. Jo, C. E. Hyde-Wright, M. Garçon, R. J. Feuerbach, L. J. Kaufman, R. Igarashi, Nilanga Liyanage, E. Kuchina, C. Ferdi, A. Kelleher, Karl Slifer, Larry Weinstein, J. Gomez, J. P. Chen, P.Y. Bertin, S. Frullani, J. S. Real, J. LeRose, F. Cusanno, A. Deur, Houbing Lu, P. Solvignon, Vladimir Nelyubin, Simon Širca, F. Garibaldi, E. Voutier, J. Roche, S. K. Nanda, Yujie Qiang, M. Potokar, P. E. Ulmer, Olfred Hansen, X. Zheng, L. Y. Zhu, Alexandre Camsonne, Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), HALL A, Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Quark, Physics, Particle physics, 010308 nuclear & particles physics, Compton scattering, FOS: Physical sciences, 13.60.Fz, 13.40.Gp, 14.20.Dh, 13.60.Hb, General Physics and Astronomy, Parton, HERA, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Helicity, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment, 010306 general physics, Nucleon, Linear combination, Scaling
Abstract

We present the first measurements of the \vec{e}p->epg cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region. The Q^2 dependence (from 1.5 to 2.3 GeV^2) of the helicity-dependent cross section indicates the twist-2 dominance of DVCS, proving that generalized parton distributions (GPDs) are accessible to experiment at moderate Q^2. The helicity-independent cross section is also measured at Q^2=2.3 GeV^2. We present the first model-independent measurement of linear combinations of GPDs and GPD integrals up to the twist-3 approximation., 5 pages, 4 figures, 2 tables. Text shortened for publication. References added. One figure removed

Published
2006

13. Measurement of the Generalized Polarizabilities of the Proton in Virtual Compton Scattering atQ2=0.92and1.76 GeV2

Author

G. Laveissière, L. Todor, N. Degrande, S. Jaminion, C. Jutier, R. Di Salvo, L. Van Hoorebeke, L. C. Alexa, B. D. Anderson, K. A. Aniol, K. Arundell, G. Audit, L. Auerbach, F. T. Baker, M. Baylac, J. Berthot, P. Y. Bertin, W. Bertozzi, L. Bimbot, W. U. Boeglin, E. J. Brash, V. Breton, H. Breuer, E. Burtin, J. R. Calarco, L. S. Cardman, C. Cavata, C.-C. Chang, J.-P. Chen, E. Chudakov, E. Cisbani, D. S. Dale, C. W. de Jager, R. De Leo, A. Deur, N. d'Hose, G. E. Dodge, J. J. Domingo, L. Elouadrhiri, M. B. Epstein, L. A. Ewell, J. M. Finn, K. G. Fissum, H. Fonvieille, G. Fournier, B. Frois, S. Frullani, C. Furget, H. Gao, J. Gao, F. Garibaldi, A. Gasparian, S. Gilad, R. Gilman, A. Glamazdin, C. Glashausser, J. Gomez, V. Gorbenko, P. Grenier, P. A. M. Guichon, J. O. Hansen, R. Holmes, M. Holtrop, C. Howell, G. M. Huber, C. E. Hyde-Wright, S. Incerti, M. Iodice, J. Jardillier, M. K. Jones, W. Kahl, S. Kato, A. T. Katramatou, J. J. Kelly, S. Kerhoas, A. Ketikyan, M. Khayat, K. Kino, S. Kox, L. H. Kramer, K. S. Kumar, G. Kumbartzki, M. Kuss, A. Leone, J. J. LeRose, M. Liang, R. A. Lindgren, N. Liyanage, G. J. Lolos, R. W. Lourie, R. Madey, K. Maeda, S. Malov, D. M. Manley, C. Marchand, D. Marchand, D. J. Margaziotis, P. Markowitz, J. Marroncle, J. Martino, K. McCormick, J. McIntyre, S. Mehrabyan, F. Merchez, Z. E. Meziani, R. Michaels, G. W. Miller, J. Y. Mougey, S. K. Nanda, D. Neyret, E. A. J. M. Offermann, Z. Papandreou, B. Pasquini, C. F. Perdrisat, R. Perrino, G. G. Petratos, S. Platchkov, R. Pomatsalyuk, D. L. Prout, V. A. Punjabi, T. Pussieux, G. Quémenér, R. D. Ransome, O. Ravel, J. S. Real, F. Renard, Y. Roblin, D. Rowntree, G. Rutledge, P. M. Rutt, A. Saha, T. Saito, A. J. Sarty, A. Serdarevic, T. Smith, G. Smirnov, K. Soldi, P. Sorokin, P. A. Souder, R. Suleiman, J. A. Templon, T. Terasawa, R. Tieulent, E. Tomasi-Gustaffson, H. Tsubota, H. Ueno, P. E. Ulmer, G. M. Urciuoli, M. Vanderhaeghen, R. Van De Vyver, R. L. J. Van der Meer, P. Vernin, B. Vlahovic, H. Voskanyan, E. Voutier, J. W. Watson, L. B. Weinstein, K. Wijesooriya, R. Wilson, B. B. Wojtsekhowski, D. G. Zainea, W-M. Zhang, J. Zhao, and Z.-L. Zhou

Subjects
Physics, Proton, 010308 nuclear & particles physics, Scattering, Momentum transfer, Compton scattering, General Physics and Astronomy, 01 natural sciences, 7. Clean energy, Nuclear physics, Paramagnetism, Dipole, Pion, Polarizability, 0103 physical sciences, Atomic physics, 010306 general physics
Abstract

We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions P(LL)-P(TT)/epsilon and P(LT), and the electric and magnetic generalized polarizabilities (GPs) alpha(E)(Q2) and beta(M)(Q2) at momentum transfer Q(2)=0.92 and 1.76 GeV2. The electric GP shows a strong falloff with Q2, and its global behavior does not follow a simple dipole form. The magnetic GP shows a rise and then a falloff; this can be interpreted as the dominance of a long-distance diamagnetic pion cloud at low Q2, compensated at higher Q2 by a paramagnetic contribution from piN intermediate states.

Published
2004

14. Precision Measurement of the Neutron Spin AsymmetryA1nand Spin-Flavor Decomposition in the Valence Quark Region

Author

E. Burtin, J. Gomez, William Bertozzi, Pete Markowitz, R. De Leo, Antonin Vacheret, D. J. Steiner, Jian-Ping Chen, S. Širca, S. Strauch, F. Marie, Baile Zhang, Paul Souder, S. K. Nanda, T. Averett, G. M. Urciuoli, H. Xiang, Sonja Dieterich, Haiyan Gao, Xiaofeng Zhu, S. Frullani, V. Sulkosky, A. Powell, X. Zheng, Dipanwita Dutta, A. Saha, D. J. Margaziotis, K. McCormick, Shalev Gilad, D. Lhuillier, C. W. de Jager, K. A. Aniol, Bryan J. Moffit, R. Roche, F. Garibaldi, D. S. Armstrong, J. R. Calarco, T. Horn, L. J. Kaufman, S. Binet, Bogdan Wojtsekhowski, F. Cusanno, E. Chudakov, E. Busato, Wolfgang Korsch, J. O. Hansen, A. Deur, C. Butuceanu, J. Roche, M. Roedelbronn, Karl Slifer, P. Solvignon, T. Pussieux, X. Jiang, B. Reitz, Z. Chai, M. Rvachev, Y. Xiao, D. Neyret, F. Xiong, Nilanga Liyanage, L. Zhu, J. J. LeRose, Z. E. Meziani, J. M. Finn, Guy Ron, Jiansong Gao, Seonho Choi, Ronald Gilman, A. Camsonne, Douglas Higinbotham, Jaideep Singh, James J. Kelly, N. Savvinov, K. Kramer, Adam M. Tobias, Gordon D. Cates, S. K. Phillips, R. Michaels, P. A. Zolnierczuk, and W. Hinton

Subjects
Quantum chromodynamics, Physics, Quark, Particle physics, Nuclear Theory, Hadron, Quark model, General Physics and Astronomy, Constituent quark, Deep inelastic scattering, Nuclear physics, Baryon, High Energy Physics::Experiment, Nuclear Experiment, Nucleon
Abstract

We have measured the neutron spin asymmetry A{sub 1}{sup n} with high precision at three kinematics in the deep inelastic region at x = 0.33, 0.47 and 0.60, and Q{sup 2} = 2.7, 3.5 and 4.8 (GeV/c){sup 2}, respectively. Our results unambiguously show, for the first time, that A{sub 1}{sup n} crosses zero around x = 0.47 and becomes significantly positive at x = 0.60. Combined with the world proton data, polarized quark distributions were extracted. Our results, in general, agree with relativistic constituent quark models and with perturbative quantum chromodynamics (pQCD) analyses based on the earlier data. However they deviate from pQCD predictions based on hadron helicity conservation.

Published
2004

15. Measurement of the generalized polarizabilities of the proton in virtual Compton scattering at Q2=0.92 and 1.76 GeV2

Author

G, Laveissière, L, Todor, N, Degrande, S, Jaminion, C, Jutier, R, Di Salvo, L, Van Hoorebeke, L C, Alexa, B D, Anderson, K A, Aniol, K, Arundell, G, Audit, L, Auerbach, F T, Baker, M, Baylac, J, Berthot, P Y, Bertin, W, Bertozzi, L, Bimbot, W U, Boeglin, E J, Brash, V, Breton, H, Breuer, E, Burtin, J R, Calarco, L S, Cardman, C, Cavata, C-C, Chang, J-P, Chen, E, Chudakov, E, Cisbani, D S, Dale, C W, de Jager, R, De Leo, A, Deur, N, d'Hose, G E, Dodge, J J, Domingo, L, Elouadrhiri, M B, Epstein, L A, Ewell, J M, Finn, K G, Fissum, H, Fonvieille, G, Fournier, B, Frois, S, Frullani, C, Furget, H, Gao, J, Gao, F, Garibaldi, A, Gasparian, S, Gilad, R, Gilman, A, Glamazdin, C, Glashausser, J, Gomez, V, Gorbenko, P, Grenier, P A M, Guichon, J O, Hansen, R, Holmes, M, Holtrop, C, Howell, G M, Huber, C E, Hyde-Wright, S, Incerti, M, Iodice, J, Jardillier, M K, Jones, W, Kahl, S, Kato, A T, Katramatou, J J, Kelly, S, Kerhoas, A, Ketikyan, M, Khayat, K, Kino, S, Kox, L H, Kramer, K S, Kumar, G, Kumbartzki, M, Kuss, A, Leone, J J, LeRose, M, Liang, R A, Lindgren, N, Liyanage, G J, Lolos, R W, Lourie, R, Madey, K, Maeda, S, Malov, D M, Manley, C, Marchand, D, Marchand, D J, Margaziotis, P, Markowitz, J, Marroncle, J, Martino, K, McCormick, J, McIntyre, S, Mehrabyan, F, Merchez, Z E, Meziani, R, Michaels, G W, Miller, J Y, Mougey, S K, Nanda, D, Neyret, E A J M, Offermann, Z, Papandreou, B, Pasquini, C F, Perdrisat, R, Perrino, G G, Petratos, S, Platchkov, R, Pomatsalyuk, D L, Prout, V A, Punjabi, T, Pussieux, G, Quémenér, R D, Ransome, O, Ravel, J S, Real, F, Renard, Y, Roblin, D, Rowntree, G, Rutledge, P M, Rutt, A, Saha, T, Saito, A J, Sarty, A, Serdarevic, T, Smith, G, Smirnov, K, Soldi, P, Sorokin, P A, Souder, R, Suleiman, J A, Templon, T, Terasawa, R, Tieulent, E, Tomasi-Gustaffson, H, Tsubota, H, Ueno, P E, Ulmer, G M, Urciuoli, M, Vanderhaeghen, R, Van De Vyver, R L J, Van der Meer, P, Vernin, B, Vlahovic, H, Voskanyan, E, Voutier, J W, Watson, L B, Weinstein, K, Wijesooriya, R, Wilson, B B, Wojtsekhowski, D G, Zainea, W-M, Zhang, J, Zhao, and Z-L, Zhou

Abstract

We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions P(LL)-P(TT)/epsilon and P(LT), and the electric and magnetic generalized polarizabilities (GPs) alpha(E)(Q2) and beta(M)(Q2) at momentum transfer Q(2)=0.92 and 1.76 GeV2. The electric GP shows a strong falloff with Q2, and its global behavior does not follow a simple dipole form. The magnetic GP shows a rise and then a falloff; this can be interpreted as the dominance of a long-distance diamagnetic pion cloud at low Q2, compensated at higher Q2 by a paramagnetic contribution from piN intermediate states.

Published
2003

16. Measurement of G(E(p))/G(M(p)) in e(--)p---e(--)p to Q(2) = 5.6 GeV(2)

Author

O, Gayou, K A, Aniol, T, Averett, F, Benmokhtar, W, Bertozzi, L, Bimbot, E J, Brash, J R, Calarco, C, Cavata, Z, Chai, C-C, Chang, T, Chang, J-P, Chen, E, Chudakov, R, De Leo, S, Dieterich, R, Endres, M B, Epstein, S, Escoffier, K G, Fissum, H, Fonvieille, S, Frullani, J, Gao, F, Garibaldi, S, Gilad, R, Gilman, A, Glamazdin, C, Glashausser, J, Gomez, V, Gorbenko, J-O, Hansen, D W, Higinbotham, G M, Huber, M, Iodice, C W, de Jager, X, Jiang, M K, Jones, J J, Kelly, M, Khandaker, A, Kozlov, K M, Kramer, G, Kumbartzki, J J, LeRose, D, Lhuillier, R A, Lindgren, N, Liyanage, G J, Lolos, D J, Margaziotis, F, Marie, P, Markowitz, K, McCormick, R, Michaels, B D, Milbrath, S K, Nanda, D, Neyret, Z, Papandreou, L, Pentchev, C F, Perdrisat, N M, Piskunov, V, Punjabi, T, Pussieux, G, Quéméner, R D, Ransome, B A, Raue, R, Roché, M, Rvachev, A, Saha, C, Salgado, S, Sirca, I, Sitnik, S, Strauch, L, Todor, E, Tomasi-Gustafsson, G M, Urciuoli, H, Voskanyan, K, Wijesooriya, B B, Wojtsekhowski, X, Zheng, and L, Zhu

Abstract

The ratio of the electric and magnetic form factors of the proton G(E(p))/G(M(p)), which is an image of its charge and magnetization distributions, was measured at the Thomas Jefferson National Accelerator Facility (JLab) using the recoil polarization technique. The ratio of the form factors is directly proportional to the ratio of the transverse to longitudinal components of the polarization of the recoil proton in the elastic e(--)p---e(--)p reaction. The new data presented span the range 3.5Q(2)5.6 GeV(2) and are well described by a linear Q(2) fit. Also, the ratio sqrt[Q(2)] F(2(p))/F(1(p)) reaches a constant value above Q(2) = 2 GeV(2).

Published
2001

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