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16 results on '"B, Wojtsekhowski"'

1. Deeply virtual Compton scattering off the neutron

Author

M. Benali, C. Desnault, M. Mazouz, Z. Ahmed, H. Albataineh, K. Allada, K. A. Aniol, V. Bellini, W. Boeglin, P. Bertin, M. Brossard, A. Camsonne, M. Canan, S. Chandavar, C. Chen, J.-P. Chen, M. Defurne, C. W. de Jager, R. de Leo, A. Deur, L. El Fassi, R. Ent, D. Flay, M. Friend, E. Fuchey, S. Frullani, F. Garibaldi, D. Gaskell, A. Giusa, O. Glamazdin, S. Golge, J. Gomez, O. Hansen, D. Higinbotham, T. Holmstrom, T. Horn, J. Huang, M. Huang, G. M. Huber, C. E. Hyde, S. Iqbal, F. Itard, Ho. Kang, Hy. Kang, A. Kelleher, C. Keppel, S. Koirala, I. Korover, J. J. LeRose, R. Lindgren, E. Long, M. Magne, J. Mammei, D. J. Margaziotis, P. Markowitz, A. Martí Jiménez-Argüello, F. Meddi, D. Meekins, R. Michaels, M. Mihovilovic, N. Muangma, C. Muñoz Camacho, P. Nadel-Turonski, N. Nuruzzaman, R. Paremuzyan, R. Pomatsalyuk, A. Puckett, V. Punjabi, Y. Qiang, A. Rakhman, M. N. H. Rashad, S. Riordan, J. Roche, G. Russo, F. Sabatié, K. Saenboonruang, A. Saha, B. Sawatzky, L. Selvy, A. Shahinyan, S. Sirca, P. Solvignon, M. L. Sperduto, R. Subedi, V. Sulkosky, C. Sutera, W. A. Tobias, G. M. Urciuoli, D. Wang, B. Wojtsekhowski, H. Yao, Z. Ye, L. Zana, X. Zhan, J. Zhang, B. Zhao, Z. Zhao, X. Zheng, P. Zhu, Laboratoire de Physique de Clermont (LPC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
quark: flavor, Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Nuclear Theory, n: structure function, nucleon, FOS: Physical sciences, General Physics and Astronomy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, High Energy Physics - Experiment, 010305 fluids & plasmas, High Energy Physics - Phenomenology, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), deeply virtual Compton scattering, 0103 physical sciences, photon: scattering, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment
Abstract

The three-dimensional structure of nucleons (protons and neutrons) is embedded in so-called generalized parton distributions, which are accessible from deeply virtual Compton scattering. In this process, a high energy electron is scattered off a nucleon by exchanging a virtual photon. Then, a highly-energetic real photon is emitted from one of the quarks inside the nucleon, which carries information on the quark's transverse position and longitudinal momentum. By measuring the cross-section of deeply virtual Compton scattering, Compton form factors related to the generalized parton distributions can be extracted. Here, we report the observation of unpolarized deeply virtual Compton scattering off a deuterium target. From the measured photon-electroproduction cross-sections, we have extracted the cross-section of a quasi-free neutron and a coherent deuteron. Due to the approximate isospin symmetry of quantum chromodynamics, we can determine the contributions from the different quark flavours to the helicity-conserved Compton form factors by combining our measurements with previous ones probing the proton's internal structure. These results advance our understanding of the description of the nucleon structure, which is important to solve the proton spin puzzle.

Published
2020
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2. Measurement of the single-spin asymmetry Ay0 in quasi-elastic 3He↑(e,e′n) scattering at 0.4 < Q2 < 1.0 GeV/c2

Author

E. Long, Y.W. Zhang, M. Mihovilovič, G. Jin, V. Sulkosky, A. Kelleher, B. Anderson, D.W. Higinbotham, S. Širca, K. Allada, J.R.M. Annand, T. Averett, W. Bertozzi, W. Boeglin, P. Bradshaw, A. Camsonne, M. Canan, G.D. Cates, C. Chen, J.-P. Chen, E. Chudakov, R. De Leo, X. Deng, A. Deur, C. Dutta, L. El Fassi, D. Flay, S. Frullani, F. Garibaldi, H. Gao, S. Gilad, R. Gilman, O. Glamazdin, S. Golge, J. Gomez, J.-O. Hansen, T. Holmstrom, J. Huang, H. Ibrahim, C.W. de Jager, E. Jensen, X. Jiang, M. Jones, H. Kang, J. Katich, H.P. Khanal, P.M. King, W. Korsch, J. LeRose, R. Lindgren, H.-J. Lu, W. Luo, P. Markowitz, M. Meziane, R. Michaels, B. Moffit, P. Monaghan, N. Muangma, S. Nanda, B.E. Norum, K. Pan, D. Parno, E. Piasetzky, M. Posik, V. Punjabi, A.J.R. Puckett, X. Qian, Y. Qiang, X. Qui, S. Riordan, A. Saha, B. Sawatzky, M. Shabestari, A. Shahinyan, B. Shoenrock, J. St. John, R. Subedi, W.A. Tobias, W. Tireman, G.M. Urciuoli, D. Wang, K. Wang, Y. Wang, J. Watson, B. Wojtsekhowski, Z. Ye, X. Zhan, Y. Zhang, X. Zheng, B. Zhao, and L. Zhu

Subjects
Nuclear Experiment, lcsh:Physics, lcsh:QC1-999
Abstract

Due to the lack of free neutron targets, studies of the structure of the neutron are typically made by scattering electrons from either 2H or 3He targets. In order to extract useful neutron information from a 3He target, one must understand how the neutron in a 3He system differs from a free neutron by taking into account nuclear effects such as final state interactions and meson exchange currents. The target single spin asymmetry Ay0 is an ideal probe of such effects, as any deviation from zero indicates effects beyond plane wave impulse approximation. New measurements of the target single spin asymmetry Ay0 at Q2 of 0.46 and 0.96 (GeV/c)2 were made at Jefferson Lab using the quasi-elastic He↑3(e,e′n) reaction. Our measured asymmetry decreases rapidly, from >20% at Q2=0.46 (GeV/c)2 to nearly zero at Q2=0.96 (GeV/c)2, demonstrating the fall-off of the reaction mechanism effects as Q2 increases. We also observed a small ϵ-dependent increase in Ay0 compared to previous measurements, particularly at moderate Q2. This indicates that upcoming high Q2 measurements from the Jefferson Lab 12 GeV program can cleanly probe neutron structure from polarized 3He using plane wave impulse approximation. Keywords: Neutron, Quasi-elastic, Polarized, 3He, Electron scattering, Single spin asymmetry

Published
2019

3. Prospect for Measuring ${G_E^n}$ at High Momentum Transfers

Author

B. Wojtsekhowski

Subjects
Physics, Nuclear physics, Physics - Instrumentation and Detectors, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Nuclear Experiment (nucl-ex), High momentum, Nuclear Experiment
Abstract

Experiment E02-013, approved by PAC21, will measure the neutron electric form factor at \qsq~up to 3.4 \gvsq, which is twice that achieved to date. The main features of the new experiment will be the use of the electron spectrometer BigBite, a large array of neutron detectors, and a polarized \he3~target. We present the parameters and optimization of the experimental setup. A concept of an experiment for \GEN~where precision \GEP~data is used for calibration of the systematics of a Rosenbluth type measurement is also discussed. A concept of the circulating gas flow in the polarized He$^3$ target is presented., 9 pages, 4 figures, contribution to the proceedings of the workshop "Exclusive processes at High Momentum Transfer", May 15-18 2002, Newport News, Virginia, page 273-281

Published
2017

4. Precision measurements of A1n in the deep inelastic regime

Author

D.S. Parno, D. Flay, M. Posik, K. Allada, W. Armstrong, T. Averett, F. Benmokhtar, W. Bertozzi, A. Camsonne, M. Canan, G.D. Cates, C. Chen, J.-P. Chen, S. Choi, E. Chudakov, F. Cusanno, M.M. Dalton, W. Deconinck, C.W. de Jager, X. Deng, A. Deur, C. Dutta, L. El Fassi, G.B. Franklin, M. Friend, H. Gao, F. Garibaldi, S. Gilad, R. Gilman, O. Glamazdin, S. Golge, J. Gomez, L. Guo, O. Hansen, D.W. Higinbotham, T. Holmstrom, J. Huang, C. Hyde, H.F. Ibrahim, X. Jiang, G. Jin, J. Katich, A. Kelleher, A. Kolarkar, W. Korsch, G. Kumbartzki, J.J. LeRose, R. Lindgren, N. Liyanage, E. Long, A. Lukhanin, V. Mamyan, D. McNulty, Z.-E. Meziani, R. Michaels, M. Mihovilovič, B. Moffit, N. Muangma, S. Nanda, A. Narayan, V. Nelyubin, B. Norum, Nuruzzaman, Y. Oh, J.C. Peng, X. Qian, Y. Qiang, A. Rakhman, S. Riordan, A. Saha, B. Sawatzky, M.H. Shabestari, A. Shahinyan, S. Širca, P. Solvignon, R. Subedi, V. Sulkosky, W.A. Tobias, W. Troth, D. Wang, Y. Wang, B. Wojtsekhowski, X. Yan, H. Yao, Y. Ye, Z. Ye, L. Yuan, X. Zhan, Y. Zhang, Y.-W. Zhang, B. Zhao, and X. Zheng

Subjects
Nucleon structure, Spin structure functions, FOS: Physical sciences, High Energy Physics::Experiment, Polarized electron scattering, Nuclear Experiment (nucl-ex), Nuclear Experiment, lcsh:Physics, lcsh:QC1-999, Parton distribution functions
Abstract

We have performed precision measurements of the double-spin virtual-photon asymmetry $A_1$ on the neutron in the deep inelastic scattering regime, using an open-geometry, large-acceptance spectrometer. Our data cover a wide kinematic range $0.277 \leq x \leq 0.548$ at an average $Q^2$ value of 3.078~(GeV/c)$^2$, doubling the available high-precision neutron data in this $x$ range. We have combined our results with world data on proton targets to extract the ratio of polarized-to-unpolarized parton distribution functions for up quarks and for down quarks in the same kinematic range. Our data are consistent with a previous observation of an $A_1^n$ zero crossing near $x=0.5$. We find no evidence of a transition to a positive slope in $(\Delta d + \Delta \bar{d})/(d + \bar{d})$ up to $x=0.548$., Comment: 6 pages, 2 figures, 3 tables. Two typos corrected in Table 3

Published
2015

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
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6. Test of the OZI rule in hadroproduction ofφφandφK+K−

Author

R. S. Longacre, E. Efstathiadis, K Vazeri, C Landberg, K. Zhao, S. J. Lindenbaum, G. S. Adams, B Wojtsekhowski, A Wright, C.S. Chan, R. W. Hackenburg, Y. Zhu, and M. A. Kramer

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Pion, OZI rule, ComputingMethodologies_SIMULATIONANDMODELING, Computer Science::Information Retrieval, ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS, ComputerSystemsOrganization_SPECIAL-PURPOSEANDAPPLICATION-BASEDSYSTEMS, High Energy Physics::Experiment, Production (computer science), Nuclear Experiment
Abstract

The cross sections for {phi}{phi} and {phi}{ital K}{sup +}{ital K}{sup {minus}} production were measured with 8 GeV/{ital c} pion and kaon beams to examine the OZI suppression of the reaction {pi}{sup {minus}}{ital p}{r_arrow}{phi}{phi}{ital n}. The measured cross section ratios indicate that this reaction is not suppressed for {phi}{phi} invariant masses up to 2.5 GeV/{ital c}{sup 2}. {copyright} {ital 1996 The American Physical Society.}

Published
1996
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7. Transverse-Longitudinal Asymmetry in the QuasielasticHe→3(e→, e′)Reaction

Author

Michael Pitt, Wolfgang Lorenzon, D. R. Tieger, B. Bray, R. Carr, E. J. Beise, J. O. Hansen, B. B. Wojtsekhowski, B. W. Filippone, Haiyan Gao, C. E. Jones, Kisoo Lee, P. U. Sauer, L. H. Kramer, E. Candell, W. Korsch, C. Tripp, J. Napolitano, D. DeSchepper, T.W. Donnelly, M. Farkhondeh, A. Lung, Ross Milner, Naomi C R Makins, G. W. Dodson, J. Arrington, R.-W. Schulze, M. A. Titko, B. Mueller, R. D. McKeown, K. Dow R. Ent, and T. P. Welch

Subjects
Physics, Nuclear reaction, Quasielastic scattering, media_common.quotation_subject, Nuclear Theory, Momentum transfer, Plane wave, General Physics and Astronomy, Asymmetry, Nuclear physics, Transverse plane, High Energy Physics::Experiment, Nuclear Experiment, Nucleon, Wave function, media_common
Abstract

The transverse-longitudinal asymmetry ATL′ in 3He→(e→, e′) quasielastic scattering at momentum transfer Q2=0.14 (GeV/c)^2 has been measured to be 1.52 ± 0.55(stat) ± 0.15(syst)%. The plane wave impulse approximation (PWIA) prediction for this measurement ranges from 2.1% to 2.9%, where the variation is due to uncertainty in the initial state wave function, nucleon form factors, and off-shell prescription. The data may suggest a suppression with respect to the PWIA, which has also been observed for the unpolarized longitudinal response function.

Published
1995
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8. Measurement of the Neutron Radius of 208Pb Through Parity-Violation in Electron Scattering

Author

S, Abrahamyan, Z, Ahmed, H, Albataineh, K, Aniol, D S, Armstrong, W, Armstrong, T, Averett, B, Babineau, A, Barbieri, V, Bellini, R, Beminiwattha, J, Benesch, F, Benmokhtar, T, Bielarski, W, Boeglin, A, Camsonne, M, Canan, P, Carter, G D, Cates, C, Chen, J-P, Chen, O, Hen, F, Cusanno, M M, Dalton, R, De Leo, K, de Jager, W, Deconinck, P, Decowski, X, Deng, A, Deur, D, Dutta, A, Etile, D, Flay, G B, Franklin, M, Friend, S, Frullani, E, Fuchey, F, Garibaldi, E, Gasser, R, Gilman, A, Giusa, A, Glamazdin, J, Gomez, J, Grames, C, Gu, O, Hansen, J, Hansknecht, D W, Higinbotham, R S, Holmes, T, Holmstrom, C J, Horowitz, J, Hoskins, J, Huang, C E, Hyde, F, Itard, C-M, Jen, E, Jensen, G, Jin, S, Johnston, A, Kelleher, K, Kliakhandler, P M, King, S, Kowalski, K S, Kumar, J, Leacock, J, Leckey, J H, Lee, J J, LeRose, R, Lindgren, N, Liyanage, N, Lubinsky, J, Mammei, F, Mammoliti, D J, Margaziotis, P, Markowitz, A, McCreary, D, McNulty, L, Mercado, Z-E, Meziani, R W, Michaels, M, Mihovilovic, N, Muangma, C, Muñoz-Camacho, S, Nanda, V, Nelyubin, N, Nuruzzaman, Y, Oh, A, Palmer, D, Parno, K D, Paschke, S K, Phillips, B, Poelker, R, Pomatsalyuk, M, Posik, A J R, Puckett, B, Quinn, A, Rakhman, P E, Reimer, S, Riordan, P, Rogan, G, Ron, G, Russo, K, Saenboonruang, A, Saha, B, Sawatzky, A, Shahinyan, R, Silwal, S, Sirca, K, Slifer, P, Solvignon, P A, Souder, M L, Sperduto, R, Subedi, R, Suleiman, V, Sulkosky, C M, Sutera, W A, Tobias, W, Troth, G M, Urciuoli, B, Waidyawansa, D, Wang, J, Wexler, R, Wilson, B, Wojtsekhowski, X, Yan, H, Yao, Y, Ye, Z, Ye, V, Yim, L, Zana, X, Zhan, J, Zhang, Y, Zhang, X, Zheng, and P, Zhu

Subjects
Nuclear Theory, FOS: Physical sciences, High Energy Physics::Experiment, Astrophysics::Earth and Planetary Astrophysics, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

We report the first measurement of the parity-violating asymmetry A_PV in the elastic scattering of polarized electrons from 208Pb. A_PV is sensitive to the radius of the neutron distribution (Rn). The result A_PV = 0.656 \pm 0.060 (stat) \pm 0.014 (syst) ppm corresponds to a difference between the radii of the neutron and proton distributions Rn - Rp = 0.33 +0.16 -0.18 fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus., Comment: 6 pages, 1 figure

Published
2012
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9. Nucleon Form Factors experiments with 12 GeV CEBAF

Author

B. Wojtsekhowski, Sigfrido Boffi, Claudio Ciofi degli Atti, Mauro Giannini, and Daniele Treleani

Subjects
Quantum chromodynamics, Nuclear physics, Physics, Particle physics, Momentum transfer, Quark–gluon plasma, Quark model, Form factor (quantum field theory), Nuclear Experiment, Deep inelastic scattering, Nucleon, High momentum
Abstract

A number of precision form factor experiments at high momentum transfer will be performed with the 11 GeV electron beam of CEBAF. We review the approved proposals and the conceptual schemes of several new suggestions. Form factor data will serve as a major input for the construction of a tomographic image of the nucleon.

Published
2008
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10. Extraction of the neutron magnetic form factor from quasielastic3He→(e→,e') atQ2=0.1−0.6 (GeV/c)2

Author

B. Anderson, L. Auberbach, T. Averett, W. Bertozzi, T. Black, J. Calarco, L. Cardman, G. D. Cates, Z. W. Chai, J. P. Chen, Seonho Choi, E. Chudakov, S. Churchwell, G. S. Corrado, C. Crawford, D. Dale, A. Deur, P. Djawotho, D. Dutta, J. M. Finn, H. Gao, R. Gilman, A. V. Glamazdin, C. Glashausser, W. Glöckle, J. Golak, J. Gomez, V. G. Gorbenko, J.-O. Hansen, F. W. Hersman, D. W. Higinbotham, R. Holmes, C. R. Howell, E. Hughes, B. Humensky, S. Incerti, C. W. de Jager, J. S. Jensen, X. Jiang, C. E. Jones, M. Jones, R. Kahl, H. Kamada, A. Kievsky, I. Kominis, W. Korsch, K. Kramer, G. Kumbartzki, M. Kuss, E. Lakuriqi, M. Liang, N. Liyanage, J. LeRose, S. Malov, D. J. Margaziotis, J. W. Martin, K. McCormick, R. D. McKeown, K. McIlhany, Z.-E. Meziani, R. Michaels, G. W. Miller, J. Mitchell, S. Nanda, E. Pace, T. Pavlin, G. G. Petratos, R. I. Pomatsalyuk, D. Pripstein, D. Prout, R. D. Ransome, Y. Roblin, M. Rvachev, A. Saha, G. Salmè, M. Schnee, J. Seely, T. Shin, K. Slifer, P. A. Souder, S. Strauch, R. Suleiman, M. Sutter, B. Tipton, L. Todor, M. Viviani, B. Vlahovic, J. Watson, C. F. Williamson, H. Witała, B. Wojtsekhowski, F. Xiong, W. Xu, J. Yeh, and P. Żołnierczuk

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Nuclear Theory, Hadron, Plane wave, Elementary particle, 01 natural sciences, 7. Clean energy, Nuclear physics, Helium-3, 0103 physical sciences, Magnetic form factor, Neutron, Nuclear Experiment, 010306 general physics, Nucleon, Isotopes of helium
Abstract

We have measured the transverse asymmetry A{sub T{sup '}} in the quasielastic {sup 3}He-vector(e-vector,e{sup '}) process with high precision at Q{sup 2} values from 0.1 to 0.6 (GeV/c){sup 2}. The neutron magnetic form factor G{sub M}{sup n} was extracted at Q{sup 2} values of 0.1 and 0.2 (GeV/c){sup 2} using a nonrelativistic Faddeev calculation which includes both final-state interactions (FSI) and meson-exchange currents (MEC). Theoretical uncertainties due to the FSI and MEC effects were constrained with a precision measurement of the spin-dependent asymmetry in the threshold region of {sup 3}He-vector(e-vector,e{sup '}). We also extracted the neutron magnetic form factor G{sub M}{sup n} at Q{sup 2} values of 0.3 to 0.6 (GeV/c){sup 2} based on plane wave impulse approximation calculations.

Published
2007
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11. Polarization Transfer in Proton Compton Scattering at High Momentum Transfer

Author

D. J. Hamilton, V. H. Mamyan, K. A. Aniol, J. R. M. Annand, P. Y. Bertin, L. Bimbot, P. Bosted, J. R. Calarco, A. Camsonne, G. C. Chang, T.-H. Chang, J.-P. Chen, Seonho Choi, E. Chudakov, A. Danagoulian, P. Degtyarenko, C. W. de Jager, A. Deur, D. Dutta, K. Egiyan, H. Gao, F. Garibaldi, O. Gayou, R. Gilman, A. Glamazdin, C. Glashausser, J. Gomez, J.-O. Hansen, D. Hayes, D. Higinbotham, W. Hinton, T. Horn, C. Howell, T. Hunyady, C. E. Hyde-Wright, X. Jiang, M. K. Jones, M. Khandaker, A. Ketikyan, V. Kubarovsky, K. Kramer, G. Kumbartzki, G. Laveissière, J. LeRose, R. A. Lindgren, D. J. Margaziotis, P. Markowitz, K. McCormick, Z.-E. Meziani, R. Michaels, P. Moussiegt, S. Nanda, A. M. Nathan, D. M. Nikolenko, V. Nelyubin, B. E. Norum, K. Paschke, L. Pentchev, C. F. Perdrisat, E. Piasetzky, R. Pomatsalyuk, V. A. Punjabi, I. Rachek, A. Radyushkin, B. Reitz, R. Roche, M. Roedelbronn, G. Ron, F. Sabatie, A. Saha, N. Savvinov, A. Shahinyan, Y. Shestakov, S. Širca, K. Slifer, P. Solvignon, P. Stoler, S. Tajima, V. Sulkosky, L. Todor, B. Vlahovic, L. B. Weinstein, K. Wang, B. Wojtsekhowski, H. Voskanyan, H. Xiang, X. Zheng, L. Zhu, 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), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), 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), HALL A, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université 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)

Subjects
Photon, Proton, Nuclear Theory, General Physics and Astronomy, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Physics, Spectrometer, 010308 nuclear & particles physics, Momentum transfer, Compton scattering, Polarization (waves), Gluon, Calorimeter, High Energy Physics - Phenomenology, High Energy Physics::Experiment
Abstract

The Jefferson Lab Hall A experiment E99-114 comprised a series of measurements to explore proton Compton scattering at high momentum transfer. For the first time, the polarisation transfer observables in the p (~ 0 ~ p) reaction were measured in the GeV energy range, where it is believed that quark-gluon degrees of freedom begin to dominate. The experiment utilised a circularly polarised photon beam incident on a liquid hydrogen target, with the scattered photon and recoil proton detected in a lead-glass calorimeter and a magnetic spectrometer, respectively.

Published
2005
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12. Precision measurement of the neutron spin asymmetryA(n)(1) and spin-flavor decomposition in the valence quark region

Author

X, Zheng, K, Aniol, D S, Armstrong, T D, Averett, W, Bertozzi, S, Binet, E, Burtin, E, Busato, C, Butuceanu, J, Calarco, A, Camsonne, G D, Cates, Z, Chai, J-P, Chen, Seonho, Choi, E, Chudakov, F, Cusanno, R De, Leo, A, Deur, S, Dieterich, D, Dutta, J M, Finn, S, Frullani, H, Gao, J, Gao, F, Garibaldi, S, Gilad, R, Gilman, J, Gomez, J-O, Hansen, D W, Higinbotham, W, Hinton, T, Horn, C W, De Jager, X, Jiang, L, Kaufman, J, Kelly, W, Korsch, K, Kramer, J, LeRose, D, Lhuillier, N, Liyanage, D J, Margaziotis, F, Marie, P, Markowitz, K, McCormick, Z-E, Meziani, R, Michaels, B, Moffit, S, Nanda, D, Neyret, S K, Phillips, A, Powell, T, Pussieux, B, Reitz, J, Roche, R, Roche, M, Roedelbronn, G, Ron, M, Rvachev, A, Saha, N, Savvinov, J, Singh, S, Sirca, K, Slifer, P, Solvignon, P, Souder, D J, Steiner, S, Strauch, V, Sulkosky, A, Tobias, G, Urciuoli, A, Vacheret, B, Wojtsekhowski, H, Xiang, Y, Xiao, F, Xiong, B, Zhang, L, Zhu, X, Zhu, and P A, Zołnierczuk

Subjects
Nuclear Theory, High Energy Physics::Experiment, Nuclear Experiment
Abstract

We have measured the neutron spin asymmetry A(n)(1) with high precision at three kinematics in the deep inelastic region at x=0.33, 0.47, and 0.60, and Q(2)=2.7, 3.5, and 4.8 (GeV/c)(2), respectively. Our results unambiguously show, for the first time, that A(n)(1) 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

13. Polarization measurements in high-energy deuteron photodisintegration

Author

C. Jones, Haiyan Gao, D. Crovelli, J. Mitchell, C. F. Perdrisat, S. Malov, S. Frullani, K. McCormick, G. M. Huber, K. Wijesooriya, P. Bosted, P. Markowitz, E. Schulte, M. K. Jones, Ronald Ransome, T. Chang, Kevin Fissum, E. Chudakov, Seonho Choi, M. Epstein, Carolina Chang, M. Rvachev, V. Gorbenko, B. Fox, Z. Chai, Arijit Saha, K. Aniol, G. J. Kumbartzki, D. Meekins, N. Liyanage, James J. Kelly, F. Xiong, B. Wojtsekhowski, R. Roche, Wenhu Xu, Jun Chen, S. Glamazdin, Edgar E. Kooijman, E. J. Brash, A. J. Sarty, S. Churchwell, S. Strauch, O. Hansen, L. Todor, Daniel Simon, J. Gomez, J. Lerose, Charles Glashausser, E. R. Kinney, Ronald Gilman, J. Hovdebo, R. Pomatsalyuk, K. Benslama, Sonja Dieterich, Michael Kuss, M. Amarian, R. Suleiman, Andrei Afanasev, R. Michaels, Demetrius Margaziotis, R. J. Holt, Jian-Rong Gao, L. Bimbot, Dipangkar Dutta, M. Liang, J. Calarco, G. M. Urciuoli, C. W. de Jager, F. Garibaldi, V. Punjabi, Z. E. Meziani, X. Jiang, S. Dumalski, P. E. Ulmer, S. Becher, R. A. Lindgren, L. Morand, O. Gayou, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), 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), HALL A, and 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)

Subjects
Nuclear reaction, Elastic scattering, Physics, Photon, 010308 nuclear & particles physics, Hadron, General Physics and Astronomy, Perturbative QCD, Acceleratorfysik och instrumentering, Polarization (waves), Accelerator Physics and Instrumentation, 7. Clean energy, 01 natural sciences, Induced polarization, Nuclear physics, Photodisintegration, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, 010306 general physics, Nuclear Experiment
Abstract

We present measurements of the recoil proton polarization for the d(gamma--,p--)n reaction at straight theta(c.m.) = 90 degrees for photon energies up to 2.4 GeV. These are the first data in this reaction for polarization transfer with circularly polarized photons. The induced polarization p(y) vanishes above 1 GeV, contrary to meson-baryon model expectations, in which resonances lead to large polarizations. However, the polarization transfer Cx does not vanish above 1 GeV, inconsistent with hadron helicity conservation. Thus, we show that the scaling behavior observed in the d(gamma,p)n cross sections is not a result of perturbative QCD. These data should provide important tests of new nonperturbative calculations in the intermediate energy regime.

Published
2001

14. Measurement of the neutron magnetic form factor from inclusive quasielastic scattering of polarized electrons from polarized 3He

Author

A. Lung, R. D. McKeown, J. O. Hansen, J. Arrington, R. Ent, Michael Pitt, B. W. Filippone, Richard G. Milner, L. H. Kramer, M. Farkhondeh, C. Tripp, E. Candell, K. Lee, R. Carr, B. B. Wojtsekhowski, D. DeSchepper, D. R. Tieger, E. J. Beise, Haiyan Gao, B. Mueller, G. W. Dodson, Jim Napolitano, W. Lorenzon, K. A. Dow, Naomi C R Makins, B. Bray, W. Korsch, C. E. Jones, and T. P. Welch

Subjects
Physics, Quasielastic scattering, Magnetic moment, media_common.quotation_subject, Electron, Asymmetry, Nuclear physics, Dipole, Magnetic form factor, Neutron, Atomic physics, Nuclear Experiment, Electron scattering, media_common
Abstract

The results of a measurement of the spin-dependent asymmetry in quasielastic scattering of longitudinally polarized electron from polarized 3He target are eported. The neutron magnetic form factor at Q2=0.19 (GeV/c)2 has been extracted from the measured asymmetry and is reported in this thesis work. The experiment was performed at the MIT-Bates Linear Accelerator Center with an incident electron beam energy of 370 MeV. Two magnetic spectrometers, MEPS and OHIPS, were used to detect the scattered electrons independently, with MEPS at the kinematics maximally sensitive to the spin-dependent transverse response function, RT', at Q2=0.19 (GeV/c)2 and OHIPS at the kinematics maximally sensitive to the spin-dependent transverse-longitudinal response function, RTL', at Q2=0.14 (GeV/c)2. The elastic asymmetry and the quasielastic asymmetry ATL' in the threshold region for three-body breakup have also been measured in OHIPS and reported. A cryogenic polarized 3He gas target using a metastability-exchange optical pumping technique was employed in this experiment. The target was operated at 13K during the experiment with an average target thickness of 3.3x10(18)cm(-2) MEPS and 1.6x10(19)cm(-2) (OHIPS). The average target polarization with 25 µA average beam current was over 38%. A GaAs source produced the polarized electrons and a Wien spin rotator was employed to rotate the spin to give longitudinally polarized electrons at the 3He target. The average beam polarization for the experiment was 36.5%. The measured 3He elastic asymmetry agrees very well with the calculated values using the 3He form factors measured by Rosenbluth separation. The measured spin-dependent transverse asymmetry, AT', which is expected to be sensitive to the neutron magnetic form factor is in good agreement with recent PWIA calculations using a spin-dependent spectral function. The neutron magnetic form factor at Q2=0.19(GeV/c)2 has been extracted from the measured asymmetry based on the recent PWIA calculations. The extracted GnM value agrees very well with the standard dipole parametrization at this Q2. This experiment represents the first measurement of the neutron magnetic form factor using spin-dependent electron scattering. The uncertainty of the extracted GnM2 is dominated by the statistical uncertainty and the uncertainty due to model dependence is found to be comparatively small. The measured ATL' in the threshold region has shown very large positive asymmetry close to the three-body breakup threshold. To interpret the AT' data, a complete calculation of the 3He asymmetry ATL' in the elastic-threshold region using a spin-dependent spectral function with final state interactions (FSI) and meson exchange currents (MEC) taken into account is probably necessary.

Published
1994

15. New versions of sources for nuclear polarized negative ion production

Author

Vadim Dudnikov, V. P. Yakushev, Yu. V. Plohinsky, A. S. Belov, A. L. Shabalin, B. B. Wojtsekhowski, and V.E. Kuzik

Subjects
inorganic chemicals, Proton, chemistry.chemical_element, Electron, Alkali metal, Polarization (waves), Charged particle, Ion, chemistry, Caesium, Physics::Atomic and Molecular Clusters, Molecule, Physics::Atomic Physics, Atomic physics, Nuclear Experiment
Abstract

Several variants of sources for nuclear polarized negative ion production have been proposed and tested. The simple adaptation of a high intensity polarized proton source for nuclear polarized H− production has been examined. A pulsed current of H− up to 0.15 mA has been obtained. For the examination of H− production in the collision of H atoms with exited alkali atoms, the conversion of a low energy atomic beam from an RF dissociator into negative ion flow by using cesium vapor target with discharge has been tested. The formation of H− ions by simultaneous operation of the RF dissociator and a discharge in the cesium target has been observed. Finally, the polarization of nuclei in molecules by collisions with electron polarized (optically pumped) alkali atoms, nuclear polarization in molecules, induced by chemical reaction in cyclic molecules, and the possibility of using this for ion sources are discussed.

Published
1992
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16. About the possibility of polarized internal target based on chemically induced dynamic nuclear polarization

Author

Yu. P. Tsentalovich, B. B. Wojtsekhowski, A. V. Yurkovskaya, S. G. Popov, and Renad Z. Sagdeev

Subjects
Chemistry, Nuclear Theory, Photodissociation, Particle accelerator, Photochemistry, Polarization (waves), Electromagnetic radiation, Chemical reaction, Molecular physics, Magnetic field, law.invention, law, Irradiation, Nuclear Experiment, Ultraviolet radiation
Abstract

The anomalously large nuclear polarization during photolysis of cyclic ketones due to chemically induced dynamic nuclear polarization was observed. Nuclear polarization in such reactions may be used for creating a polarized target.(AIP)

Published
1989
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