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1. A glimpse of gluons through deeply virtual compton scattering on the proton

Author

M. Defurne, A. Martí Jiménez-Argüello, Z. Ahmed, H. Albataineh, K. Allada, K. A. Aniol, V. Bellini, M. Benali, W. Boeglin, P. Bertin, M. Brossard, A. Camsonne, M. Canan, S. Chandavar, C. Chen, J.-P. Chen, C. W. de Jager, R. de Leo, C. Desnault, 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, C. E. Hyde, S. Iqbal, F. Itard, H. 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, M. Mazouz, F. Meddi, D. Meekins, R. Michaels, M. Mihovilovic, C. Muñoz Camacho, P. Nadel-Turonski, N. Nuruzzaman, R. Paremuzyan, 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, X. Zhan, J. Zhang, B. Zhao, Z. Zhao, X. Zheng, and P. Zhu

Subjects
Science
Abstract

It remains a challenge to find the structure and the distribution of the constituents of nucleons. Here the authors use a scattering method to get information about the gluons and quarks inside a proton and separate the contribution of Bethe-Heitler from the deeply virtual Compton scattering process.

Published
2017
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2. Electroexcitation of the Δ+(1232) at low momentum transfer

Author

A. Blomberg, D. Anez, N. Sparveris, A.J. Sarty, M. Paolone, S. Gilad, D. Higinbotham, Z. Ahmed, H. Albataineh, K. Allada, B. Anderson, K. Aniol, J. Annand, J. Arrington, T. Averett, H. Baghdasaryan, X. Bai, A. Beck, S. Beck, V. Bellini, F. Benmokhtar, W. Boeglin, C.M. Camacho, A. Camsonne, C. Chen, J.P. Chen, K. Chirapatpimol, E. Cisbani, M. Dalton, W. Deconinck, M. Defurne, R. De Leo, D. Flay, N. Fomin, M. Friend, S. Frullani, E. Fuchey, F. Garibaldi, R. Gilman, C. Gu, D. Hamilton, C. Hanretty, O. Hansen, M. Hashemi Shabestari, O. Hen, T. Holmstrom, M. Huang, S. Iqbal, N. Kalantarians, H. Kang, A. Kelleher, M. Khandaker, I. Korover, J. Leckey, J. LeRose, R. Lindgren, E. Long, J. Mammei, D.J. Margaziotis, A. Martí Jimenez-Arguello, D. Meekins, Z.E. Meziani, M. Mihovilovic, N. Muangma, B. Norum, Nuruzzaman, K. Pan, S. Phillips, E. Piasetzky, A. Polychronopoulou, I. Pomerantz, M. Posik, V. Punjabi, X. Qian, A. Rakhman, P.E. Reimer, S. Riordan, G. Ron, A. Saha, E. Schulte, L. Selvy, R. Shneor, S. Sirca, J. Sjoegren, R. Subedi, V. Sulkosky, W. Tireman, D. Wang, J. Watson, B. Wojtsekhowski, W. Yan, I. Yaron, Z. Ye, X. Zhan, J. Zhang, Y. Zhang, B. Zhao, Z. Zhao, X. Zheng, and P. Zhu

Subjects
CMR, Pion electroproduction, Nucleon deformation, Physics, QC1-999
Abstract

We report on new p(e,e′p)π∘ measurements at the Δ+(1232) resonance at the low momentum transfer region, where the mesonic cloud dynamics is predicted to be dominant and rapidly changing, offering a test bed for chiral effective field theory calculations. The new data explore the Q2 dependence of the resonant quadrupole amplitudes and for the first time indicate that the Electric and the Coulomb quadrupole amplitudes converge as Q2→0. The measurements of the Coulomb quadrupole amplitude have been extended to the lowest momentum transfer ever reached, and suggest that more than half of its magnitude is attributed to the mesonic cloud in this region. The new data disagree with predictions of constituent quark models and are in reasonable agreement with dynamical calculations that include pion cloud effects, chiral effective field theory and lattice calculations. The measurements indicate that improvement is required to the theoretical calculations and provide valuable input that will allow their refinements.

Published
2016
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3. 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

4. Novel observation of isospin structure of short-range correlations in calcium isotopes

Author

V. Bellini, A. Daniel, R. Shneor, Juliette Mammei, Simon Širca, Chunhui Chen, Shalev Gilad, F. Garibaldi, J. Leckey, K. A. Aniol, C. Hanretty, Nadia Fomin, S. K. Phillips, M. Hashemi Shabestari, Guy Ron, Z. E. Meziani, T. Averett, A. Shahinyan, S. Iqbal, Kalyan Allada, N. Muangma, R. Subedi, A. Saha, Wouter Deconinck, Ishay Pomerantz, M. Mihovilovic, I. Korover, X. Zhan, D. Anez, P. Aguilera, D. J. Margaziotis, J.-O. Hansen, Ping Zhu, Yujie Qiang, S. A. Wood, E. Cisbani, R. A. Lindgren, J. J. LeRose, P. E. Reimer, Z. Ye, B. E. Norum, V. A. Punjabi, M. Friend, Fatiha Benmokhtar, Karl Slifer, E. Fuchey, John Arrington, V. Sulkosky, Donal Day, Nikolaos Sparveris, Y. Zhang, D. Wang, S. Beck, E. Long, M. Posik, Jie Zhang, X. Bai, Xin Qian, D. Flay, A. Kelleher, M. M. Dalton, S. Riordan, J. W. Watson, D. G. Meekins, N. Kalantarians, Bogdan Wojtsekhowski, Paul Gueye, Nuruzzaman, S. Frullani, D. Nguyen, G. Jin, R. Zielinski, X. Zheng, Brian P. Anderson, R. Michaels, Shanfeng Li, Alexandre Camsonne, A. Beck, B. Zhao, C. Munoz Camacho, H. Kang, D. Gaskell, Douglas Higinbotham, M. Defurne, J. R. M. Annand, K. Pan, Abdurahim Rakhman, E. Piasetzky, M. Huang, P. Solvignon, C. Gu, I. Yaron, H. Al-Bataineh, S. Glamazdin, Larry Weinstein, Ronald Gilman, L. Selvy, Pete Markowitz, J. P. Chen, H. Baghdasaryan, K. Chirapatpimol, Z. Ahmed, X. Qiu, O. Rondon-Aramayo, 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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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), Jefferson Lab Hall A, 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
Triple coincidence, Physics, 010308 nuclear & particles physics, Nuclear Theory, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 3. Good health, Isotopes of calcium, Isospin, 0103 physical sciences, Nuclear Experiment (nucl-ex), Nucleon-Nucleon Interaction, 010306 general physics, Nucleon, Nuclear Experiment, Few-Body Systems, Range (computer programming), Mathematical physics
Abstract

Short Range Correlations (SRCs) have been identified as being responsible for the high momentum tail of the nucleon momentum distribution, n(k). Hard, short-range interactions of nucleon pairs generate the high momentum tail and imprint a universal character on n(k) for all nuclei at large momentum. Triple coincidence experiments have shown a strong dominance of np pairs, but these measurements involve large final state interactions. This paper presents the results from Jefferson Lab experiment E08014 which measured inclusive electron scattering cross-section from Ca isotopes. By comparing the inclusive cross section from 48Ca to 40Ca in a kinematic region dominated by SRCs we provide a new way to study the isospin structure of SRCs., Comment: 7 pages, 3 figures

Published
2020
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5. Electroexcitation of the Δ+(1232) at low momentum transfer

Author

V. Bellini, C.M. Camacho, E. Schulte, H. Albataineh, J. W. Watson, M. Huang, M. Hashemi Shabestari, J. Sjoegren, C. Gu, Simon Širca, F. Garibaldi, I. Yaron, L. Selvy, M. Khandaker, V. A. Punjabi, T. Holmstrom, E. Fuchey, B. D. Anderson, M. Defurne, W. Tireman, D. J. Margaziotis, R. A. Lindgren, Or Hen, J. P. Chen, I. Korover, E. Piasetzky, Z. E. Meziani, A. Blomberg, H. Baghdasaryan, Olfred Hansen, K. Chirapatpimol, J. R. M. Annand, Juliette Mammei, A. Polychronopoulou, Salvatore Frullani, M. Posik, N. Muangma, X. Zhan, S. K. Phillips, John Arrington, X. Bai, J. Leckey, D. Flay, Nikos Sparveris, Ping Zhu, B. Zhao, Guy Ron, David Hamilton, W. B. Yan, A. Kelleher, X. Zheng, N. Kalantarians, R. Shneor, S. Riordan, Abdurahim Rakhman, A. Saha, Kalyan Allada, Vincent Sulkosky, Z. W. Zhao, Z. Ye, E. Long, Xin Qian, R. Subedi, D. G. Meekins, Bogdan Wojtsekhowski, B. E. Norum, J. LeRose, R. De Leo, M. Mihovilovič, A. Martí Jiménez-Argüello, E. Cisbani, S. Iqbal, M. M. Dalton, W. U. Boeglin, Chunhui Chen, H. Kang, A. Camsonne, Nuruzzaman, Michael Paolone, C. Hanretty, D. Anez, N. Fomin, Shalev Gilad, K. A. Aniol, T. Averett, Wouter Deconinck, Ishay Pomerantz, Z. Ahmed, A. J. Sarty, Fatiha Benmokhtar, D. Wang, S. Beck, Ronald Gilman, Douglas Higinbotham, K. Pan, Yiyang Zhang, A. Beck, Jie Zhang, M. Friend, P. E. Reimer, 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), Ecole Centrale Paris, 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), 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
Angular momentum, Nuclear and High Energy Physics, High Energy Physics::Lattice, Nuclear Theory, Constituent quark, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nucleon deformation, 01 natural sciences, 7. Clean energy, Atomic, Nuclear physics, Pion, Particle and Plasma Physics, 0103 physical sciences, Coulomb, Effective field theory, Nuclear, CMR, 010306 general physics, Nuclear Experiment, Mathematical Physics, Physics, 010308 nuclear & particles physics, Momentum transfer, Pion electroproduction, Molecular, Nuclear & Particles Physics, lcsh:QC1-999, Quantum electrodynamics, Quadrupole, Nucleon, Astronomical and Space Sciences, lcsh:Physics
Abstract

International audience; We report on new p(e,e′p)π∘p(e,e′p)π∘ measurements at the Δ+(1232)Δ+(1232) resonance at the low momentum transfer region, where the mesonic cloud dynamics is predicted to be dominant and rapidly changing, offering a test bed for chiral effective field theory calculations. The new data explore the Q2Q2 dependence of the resonant quadrupole amplitudes and for the first time indicate that the Electric and the Coulomb quadrupole amplitudes converge as Q2→0Q2→0. The measurements of the Coulomb quadrupole amplitude have been extended to the lowest momentum transfer ever reached, and suggest that more than half of its magnitude is attributed to the mesonic cloud in this region. The new data disagree with predictions of constituent quark models and are in reasonable agreement with dynamical calculations that include pion cloud effects, chiral effective field theory and lattice calculations. The measurements indicate that improvement is required to the theoretical calculations and provide valuable input that will allow their refinements.

Published
2016

6. Search for three-nucleon short-range correlations in light nuclei

Author

L. Selvy, P. E. Reimer, M. Hashemi Shabestari, Wouter Deconinck, T. Averett, Karl Slifer, M. M. Dalton, H. Baghdasaryan, S. Riordan, Z. Ahmed, X. Qiu, S. Glamazdin, O. Rondon-Aramayo, X. Zhan, S. A. Wood, M. Posik, X. Bai, Yujie Qiang, N. Kalantarians, Zein-Eddine Meziani, E. Piasetzky, Larry Weinstein, P. Solvignon, Nuruzzaman, Z. Ye, B. E. Norum, Kalyan Allada, Nikolaos Sparveris, Ishay Pomerantz, N. Fomin, J. R. M. Annand, A. Kelleher, Shalev Gilad, J. Arrington, Abdurahim Rakhman, D. Wang, S. Beck, Ronald Gilman, K. A. Aniol, J. O. Hansen, B. Zhao, J. W. Watson, Juliette Mammei, Arijit Saha, M. Huang, E. Fuchey, Paul Gueye, Chunhui Chen, C. Gu, Douglas Higinbotham, I. Korover, Bogdan Wojtsekhowski, R. Michaels, H. Kang, Fatiha Benmokhtar, R. Shneor, A. Shahinyan, C. Munoz Camacho, M. Defurne, A. Camsonne, K. Chirapatpimol, I. Yaron, G. Jin, S. Iqbal, X. Zheng, Xin Qian, R. Subedi, D. J. Margaziotis, K. Pan, Pete Markowitz, D. G. Meekins, H. Albataineh, Vincent Sulkosky, B. D. Anderson, J. LeRose, Yiyang Zhang, A. Beck, P. Aguilera, A. Daniel, R. A. Lindgren, Donal Day, D. Gaskell, Guy Ron, D. Nguyen, D. Flay, C. Hanretty, N. Muangma, S. K. Phillips, M. Friend, M. Mihovilovic, Jie Zhang, E. Cisbani, Jian-Ping Chen, S. Frullani, J. Leckey, R. Zielinski, V. A. Punjabi, D. Anez, E. Long, Ping Zhu, V. Bellini, Simon Širca, F. Garibaldi, 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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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), 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 Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Light nucleus, Nuclear and High Energy Physics, 010308 nuclear & particles physics, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 3. Good health, Combinatorics, 0103 physical sciences, Nuclear Experiment (nucl-ex), 010306 general physics, Nucleon, Nuclear Experiment, Range (computer programming)
Abstract

We present new data probing short-range correlations (SRCs) in nuclei through the measurement of electron scattering off high-momentum nucleons in nuclei. The inclusive 4He/3He cross section ratio is observed to be both x and Q2 independent for 1.5 < x < 2, confirming the dominance of two- nucleon (2N) short-range correlations (SRCs). For x > 2, our data do not support a previous claim of three-nucleon (3N) correlation dominance. While contributions beyond those from stationary 2N- SRCs are observed, our data show that isolating 3N-SRCs is more complicated than for 2N-SRCs., 6 pages, 2 figures, new experimental results from JLab E08-014

Published
2018

7. Rosenbluth Separation of the π0 Electroproduction Cross Section Off the Neutron

Author

N. Nuruzzaman, S. Golge, M. L. Sperduto, Bogdan Wojtsekhowski, R. A. Lindgren, J. J. LeRose, C. M. Sutera, Chunhui Chen, Z. W. Zhao, Z. Ye, M. Mihovilovic, H. Albataineh, H. Yao, D. Flay, N. Muangma, V. Bellini, A. Martí Jiménez-Argüello, Yujie Qiang, A. Saha, M. Huang, Andrew Puckett, D. G. Meekins, Z. Ahmed, B. Zhao, F. Sabatié, Simon Širca, G. M. Huber, Pete Markowitz, S. Koirala, F. Garibaldi, L. El Fassi, W. U. Boeglin, C. E. Hyde, Tanja Horn, X. Zhan, D. J. Margaziotis, M. Brossard, S. Chandavar, Maxime Defurne, R. De Leo, D. Gaskell, M. Benali, C. W. de Jager, K. A. Aniol, M. Mazouz, P. Solvignon, O. Glamazdin, M. Magne, Olfred Hansen, A. Deur, Cynthia Keppel, A. Camsonne, Douglas Higinbotham, M. N. H. Rashad, A. Shahinyan, Vincent Sulkosky, V. A. Punjabi, Mustafa Canan, C. Desnault, Kalyan Allada, E. Long, J. Roche, S. Iqbal, William A. Tobias, E. Fuchey, I. Korover, A. Giusa, Abdurahim Rakhman, A. Kelleher, G.V. Russo, Ho. Kang, J. P. Chen, X. Zheng, L. Selvy, D. Wang, Juliette Mammei, L. Zana, J. Huang, G. M. Urciuoli, J. Gomez, Rolf Ent, S. Riordan, P.Y. Bertin, P. Nadel-Turonski, P. Zhu, H. Kang, Franco Meddi, M. Friend, Jie Zhang, S. Frullani, R. Paremuzyan, Kiadtisak Saenboonruang, R. Subedi, B. Sawatzky, F. Itard, T. Holmstrom, R. Michaels, and C. Munoz Camacho

Subjects
Quark, Physics, Particle physics, Meson, 010308 nuclear & particles physics, Nuclear Theory, Momentum transfer, General Physics and Astronomy, Parton, 01 natural sciences, 7. Clean energy, Nuclear physics, Recoil, 0103 physical sciences, Photon polarization, High Energy Physics::Experiment, Neutron, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

We report the first longitudinal-transverse separation of the deeply virtual exclusive π^{0} electroproduction cross section off the neutron and coherent deuteron. The corresponding four structure functions dσ_{L}/dt, dσ_{T}/dt, dσ_{LT}/dt, and dσ_{TT}/dt are extracted as a function of the momentum transfer to the recoil system at Q^{2}=1.75 GeV^{2} and x_{B}=0.36. The ed→edπ^{0} cross sections are found compatible with the small values expected from theoretical models. The en→enπ^{0} cross sections show a dominance from the response to transversely polarized photons, and are in good agreement with calculations based on the transversity generalized parton distributions of the nucleon. By combining these results with previous measurements of π^{0} electroproduction off the proton, we present a flavor decomposition of the u and d quark contributions to the cross section.

Published
2017

8. Rosenbluth Separation of the π^{0} Electroproduction Cross Section Off the Neutron

Author

M, Mazouz, Z, Ahmed, H, Albataineh, K, Allada, K A, Aniol, V, Bellini, M, Benali, 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, C, Desnault, 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, 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, and P, Zhu

Abstract

We report the first longitudinal-transverse separation of the deeply virtual exclusive π^{0} electroproduction cross section off the neutron and coherent deuteron. The corresponding four structure functions dσ_{L}/dt, dσ_{T}/dt, dσ_{LT}/dt, and dσ_{TT}/dt are extracted as a function of the momentum transfer to the recoil system at Q^{2}=1.75 GeV^{2} and x_{B}=0.36. The ed→edπ^{0} cross sections are found compatible with the small values expected from theoretical models. The en→enπ^{0} cross sections show a dominance from the response to transversely polarized photons, and are in good agreement with calculations based on the transversity generalized parton distributions of the nucleon. By combining these results with previous measurements of π^{0} electroproduction off the proton, we present a flavor decomposition of the u and d quark contributions to the cross section.

Published
2017

9. A glimpse of gluons through deeply virtual compton scattering on the proton

Author

J. Huang, S. Riordan, M. Brossard, I. Korover, N. Nuruzzaman, S. Golge, H. Al-Bataineh, P. Bertin, William A. Tobias, Abdurahim Rakhman, H. Kang, H. Yao, A. Camsonne, Franco Meddi, Yujie Qiang, M. Huang, A. Kelleher, A. Martí Jiménez-Argüello, S. Koirala, Kiadtisak Saenboonruang, D. J. Margaziotis, Andrew Puckett, T. Horn, E. Fuchey, G.V. Russo, R. Ent, Z. W. Zhao, Z. Ye, S. Chandavar, J. LeRose, R. De Leo, O. Glamazdin, Olfred Hansen, E. Long, F. Garibaldi, V. Bellini, L. Selvy, Bogdan Wojtsekhowski, M. N. H. Rashad, R. A. Lindgren, Cynthia Keppel, P. Markowitz, Jian-Ping Chen, X. Zhan, M. Mihovilovic, Juliette Mammei, Arijit Saha, J. Gomez, V. A. Punjabi, S. Frullani, P. Nadel-Turonski, Alexandre Deur, K. A. Aniol, Chunhui Chen, S. Širca, D. Wang, F. Sabatié, X. Zheng, R. Paremuzyan, Ping Zhu, Mustafa Canan, Kalyan Allada, R. Michaels, D. G. Meekins, C. M. Sutera, M. L. Sperduto, M. Magne, Charles Hyde, B. Zhao, D. Flay, P. Solvignon, L. El Fassi, W. U. Boeglin, M. Defurne, M. Mazouz, Jie Zhang, B. Sawatzky, M. Benali, C. Desnault, Vincent Sulkosky, S. Iqbal, F. Itard, J. Roche, M. Friend, T. Holmstrom, D. Gaskell, Douglas Higinbotham, A. Giusa, A. Shahinyan, C. W. de Jager, C. Muñoz Camacho, Z. Ahmed, G. M. Urciuoli, R. Subedi, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), 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), 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 National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, 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 ), Laboratoire de Physique de Clermont ( LPC ), 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
Genetics and Molecular Biology (all), Photon, Proton, High Energy Physics::Lattice, Nuclear Theory, General Physics and Astronomy, Virtual particle, parton: distribution function, Biochemistry, 01 natural sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], p: structure function, Nuclear Experiment (nucl-ex), [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], lcsh:Science, Nuclear Experiment, Physics, energy: high, Multidisciplinary, strong interaction, Chemistry (all), Compton scattering: form factor, photon: energy spectrum, High Energy Physics - Phenomenology, confinement, +electron+p+photon%22">electron p --> electron p photon, channel cross section: measured, Quark, electron p: deep inelastic scattering, Particle physics, electron: polarized beam, Science, Strong interaction, FOS: Physical sciences, Bethe-Heitler, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Article, General Biochemistry, Genetics and Molecular Biology, energy dependence, quark, Physics and Astronomy (all), [ PHYS.HEXP ] Physics [physics]/High Energy Physics - Experiment [hep-ex], photon: emission, deeply virtual Compton scattering, 0103 physical sciences, structure, 010306 general physics, quantum mechanics: interference, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Compton scattering, General Chemistry, gluon, sensitivity, Gluon, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Quark–gluon plasma, lcsh:Q, [ PHYS.HPHE ] Physics [physics]/High Energy Physics - Phenomenology [hep-ph], High Energy Physics::Experiment, holography, Biochemistry, Genetics and Molecular Biology (all), photon: virtual, experimental results
Abstract

The internal structure of nucleons (protons and neutrons) remains one of the greatest outstanding problems in modern nuclear physics. By scattering high-energy electrons off a proton we are able to resolve its fundamental constituents and probe their momenta and positions. Here we investigate the dynamics of quarks and gluons inside nucleons using deeply virtual Compton scattering (DVCS)—a highly virtual photon scatters off the proton, which subsequently radiates a photon. DVCS interferes with the Bethe-Heitler (BH) process, where the photon is emitted by the electron rather than the proton. We report herein the full determination of the BH-DVCS interference by exploiting the distinct energy dependences of the DVCS and BH amplitudes. In the regime where the scattering is expected to occur off a single quark, measurements show an intriguing sensitivity to gluons, the carriers of the strong interaction., It remains a challenge to find the structure and the distribution of the constituents of nucleons. Here the authors use a scattering method to get information about the gluons and quarks inside a proton and separate the contribution of Bethe-Heitler from the deeply virtual Compton scattering process.

Published
2017

10. Rosenbluth Separation of the π^{0} Electroproduction Cross Section

Author

M. Brossard, E. Long, William A. Tobias, A. Kelleher, A. Saha, D. J. Margaziotis, Pete Markowitz, Bogdan Wojtsekhowski, D. G. Meekins, R. Subedi, O. Glamazdin, Chunhui Chen, S. Chandavar, C. M. Sutera, F. Sabatié, R. De Leo, Olfred Hansen, Maxime Defurne, J. P. Chen, Kiadtisak Saenboonruang, L. El Fassi, W. U. Boeglin, N. Nuruzzaman, B. Sawatzky, Abdurahim Rakhman, S. Golge, M. Magne, M. N. H. Rashad, J. Huang, G. M. Urciuoli, M. Friend, S. Koirala, A. Martí Jiménez-Argüello, S. Riordan, C. W. de Jager, K. A. Aniol, P. Nadel-Turonski, Yujie Qiang, H. Yao, R. A. Lindgren, J. J. LeRose, Andrew Puckett, A. Deur, C. E. Hyde, I. Korover, R. Michaels, Cynthia Keppel, X. Zhan, Z. W. Zhao, Z. Ye, E. Fuchey, Jie Zhang, V. A. Punjabi, P.Y. Bertin, C. Desnault, H. Albataineh, P. Zhu, M. Mazouz, Z. Ahmed, Ho. Kang, G.V. Russo, L. Selvy, R. Paremuzyan, D. Flay, X. Zheng, S. Frullani, V. Bellini, L. Zana, M. Huang, Simon Širca, G. M. Huber, F. Garibaldi, H. Kang, M. Benali, A. Camsonne, Vincent Sulkosky, Juliette Mammei, Franco Meddi, Rolf Ent, J. Roche, D. Gaskell, J. Gomez, M. L. Sperduto, A. Shahinyan, P. Solvignon, Mustafa Canan, Kalyan Allada, M. Mihovilovic, N. Muangma, S. Iqbal, D. Wang, Douglas Higinbotham, F. Itard, T. Holmstrom, C. Muñoz Camacho, B. Zhao, A. Giusa, Tanja Horn, Département de Physique des Particules (ex SPP) (DPhP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), 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 Jefferson Lab Hall A

Subjects
Particle physics, longitudinal, interference, General Physics and Astronomy, parton: distribution function, Parton, hard exclusive electroproduction, mesons, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, pi: distribution amplitude, generalized parton distribution: transversity, Pion, deep inelastic scattering, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], quantum chromodynamics: perturbation theory, 010306 general physics, Nuclear Experiment, Quantum chromodynamics, Physics, 010308 nuclear & particles physics, scattering amplitude, momentum transfer, Sigma, nucleon: generalized parton distribution, Scattering amplitude, transverse, Distribution (mathematics), Amplitude, pi0: electroproduction, twist, High Energy Physics::Experiment, Nucleon, channel cross section: measured, Jefferson Lab, experimental results
Abstract

We present deeply virtual $\pi^0$ electroproduction cross-section measurements at $x_B$=0.36 and three different $Q^2$--values ranging from 1.5 to 2 GeV$^2$, obtained from experiment E07-007 that ran in the Hall A at Jefferson Lab. The Rosenbluth technique was used to separate the longitudinal and transverse responses. Results demonstrate that the cross section is dominated by its transverse component, and thus is far from the asymptotic limit predicted by perturbative Quantum Chromodynamics. An indication of a non-zero longitudinal contribution is provided by the interference term $\sigma_{LT}$ also measured. Results are compared with several models based on the leading twist approach of Generalized Parton Distributions (GPDs). In particular, a fair agreement is obtained with models where the scattering amplitude is described by a convolution of chiral-odd (transversity) GPDs of the nucleon with the twist-3 pion distribution amplitude. Therefore, neutral pion electroproduction may offer the exciting possibility of accessing transversity GPDs through experiment., Comment: Submitted to Physical Review Letters

Published
2016

11. Probing the Repulsive Core of the Nucleon-Nucleon Interaction via theHe4(e,e′pN)Triple-Coincidence Reaction

Author

I. Korover, B. Zhao, Chunhui Chen, Karl Slifer, R. Shneor, Whitney Armstrong, Larry Weinstein, Salvatore Frullani, Franco Garibaldi, Wouter Deconinck, D. J. Margaziotis, A. Daniel, Simon Širca, N. Muangma, L. Selvy, J. P. Chen, G. Jin, X. Zheng, Bellini, S. K. Phillips, R. Subedi, E. Long, D. Wang, Ronald Gilman, John Arrington, E. Cisbani, Maxime Defurne, I. Yaron, P. Monaghan, Z. Ahmed, P. E. Reimer, Or Hen, H. Kang, O. Rondon-Aramayo, Bogdan Wojtsekhowski, T. Badman, Douglas Higinbotham, Z. E. Meziani, H. Baghdasaryan, M. Mihovilovič, T. Averett, William Bertozzi, Xin Qian, Marti Jimenez-Arguello A, Ping Zhu, Z. W. Zhao, Z. Ye, B. E. Norum, A. Saha, O. Glamazdin, K. Chirapatpimol, D. G. Meekins, Juliette Mammei, P. Solvignon, Ishay Pomerantz, Yujie Qiang, David Hamilton, Kalyan Allada, W. B. Yan, J. R. M. Annand, Pete Markowitz, M. Posik, Hashemi Shabestari M, D. Anez, K. Pan, X. Bai, Munoz Camacho C, W. U. Boeglin, B. D. Anderson, R. A. Lindgren, J. J. LeRose, Nuruzzaman, E. Piasetzky, H. Albataineh, Fatiha Benmokhtar, Nikolaos Sparveris, J. O. Hansen, Beck S, Yiyang Zhang, M. M. Dalton, N. Fomin, A. Beck, Punjabi, E. Fuchey, D. Gaskell, D. Flay, P. Aguilera, S. Riordan, E. Schulte, de Jager Cw, Paul Gueye, Donal Day, A. Camsonne, M. Huang, S. A. Wood, T. Holmstrom, C. Hanretty, J. Sjoegren, Kalantarians N, A. Kelleher, Abdurahim Rakhman, X. Qiu, R. Michaels, A. Shahinyan, Gu C, S. Iqbal, Guy Ron, J. Bittner, W. Tireman, J. Leckey, De Leo R, Sulkosky, Jie Zhang, R. Zielinski, J. W. Watson, Khandaker M, X. Zhan, M. Friend, Shalev Gilad, and K. A. Aniol

Subjects
Physics, Range (particle radiation), Proton, Nuclear Theory, General Physics and Astronomy, Momentum, Nuclear physics, Isospin, Neutron, Tensor, Atomic physics, Nuclear Experiment, Nucleon, Excitation
Abstract

We studied simultaneously the 4He(e,e'p), 4He(e,e'pp), and 4He(e,e'pn) reactions at Q2=2 [GeV/c]2 and xB >1, for a (e,e'p) missing-momentum range of 400 to 830 MeV/c. The knocked-out proton was detected in coincidence with a proton or neutron recoiling almost back to back to the missing momentum, leaving the residual A=2 system at low excitation energy. These data were used to identify two-nucleon short-range correlated pairs and to deduce their isospin structure as a function of missing momentum in a region where the nucleon-nucleon force is expected to change from predominantly tensor to repulsive. Neutron-proton pairs dominate the high-momentum tail of the nucleon momentum distributions, but their abundance is reduced as the nucleon momentum increases beyond ~500 MeV/c. The extracted fraction of proton-proton pairs is small and almost independent of the missing momentum in the range we studied. Our data are compared with ab-initio calculations of two-nucleon momentum distributions in 4He.

Published
2014

12. Search for a New Gauge Boson in Electron-Nucleus Fixed-Target Scattering by the APEX Experiment

Author

D. Walz, E. Piasetzky, M. M. Dalton, A.C. Odian, C. Field, J. McDonald, Eric L. N. Jensen, R. Michaels, Bogdan Wojtsekhowski, J. Bono, Ishay Pomerantz, L. Selvy, J. O. Hansen, K. Bartlett, M. Oriunno, Philip Schuster, T. Holmstrom, T. Averett, R. Partridge, Vladimir Nelyubin, C. W. de Jager, R. Essig, R. Subedi, J. A. Jaros, Yujie Qiang, Neil Goeckner-Wald, Natalia Toro, S. Riordan, Y. Roblin, A. Barbieri, A. Kelleher, Pete Markowitz, Z. Ahmed, M. Khandaker, V. Maxwell, A. Camsonne, J. LeRose, D. Anez, J. Segal, T. Maruyama, James Boyce, E. Long, J. Huang, M. Paolone, S. Mayilyan, Jie Zhang, James Baker Beacham, E. Folts, Kalyan Allada, M. T. Graham, Douglas Higinbotham, B. Sawatzky, K.C. Moffeit, R. A. Lindgren, S. Abrahamyan, J. Donaghy, Ashot Gasparian, Vincent Sulkosky, S. Stepanyan, Nilanga Liyanage, J. Gomez, P. Brindza, Kyle Cranmer, Juliette Mammei, A. Shahinyan, and S. Iqbal

Subjects
Coupling, Physics, Particle physics, Range (particle radiation), Gauge boson, 010308 nuclear & particles physics, Scattering, General Physics and Astronomy, Electron, 01 natural sciences, Resonance (particle physics), Dark photon, Nuclear physics, 0103 physical sciences, Nuclear Experiment, 010306 general physics, Boson
Abstract

We present a search at the Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling α' to electrons. Such a particle A' can be produced in electron-nucleus fixed-target scattering and then decay to an e + e- pair, producing a narrow resonance in the QED trident spectrum. Using APEX test run data, we searched in the mass range 175-250 MeV, found no evidence for an A'→ e+ e- reaction, and set an upper limit of α'/α ~/= 10(-6). Our findings demonstrate that fixed-target searches can explore a new, wide, and important range of masses and couplings for sub-GeV forces.

Published
2011

13. Deeply virtual compton scattering off the neutron

Author

B. Zhao, Rolf Ent, P. Solvignon, V. Bellini, Mustafa Canan, Kalyan Allada, Tanja Horn, P. Nadel-Turonski, S. Koirala, G.V. Russo, C. M. Sutera, J. P. Chen, M. N. H. Rashad, Simon Širca, J. Huang, G. M. Urciuoli, A. Shahinyan, S. Iqbal, G. M. Huber, F. Garibaldi, M. Friend, Douglas Higinbotham, D. J. Margaziotis, Kiadtisak Saenboonruang, M. L. Sperduto, Maxime Defurne, F. Itard, Cynthia Keppel, L. Selvy, N. Muangma, Ho. Kang, T. Holmstrom, L. Zana, Pete Markowitz, R. I. Pomatsalyuk, V. A. Punjabi, Arijit Saha, William A. Tobias, B. Sawatzky, Abdurahim Rakhman, Chunhui Chen, M. Huang, Juliette Mammei, J. LeRose, F. Sabatié, X. Zhan, R. De Leo, A. Giusa, M. Benali, H. Yao, R. Michaels, A. Kelleher, Jie Zhang, A. Camsonne, I. Korover, H. Kang, C. Munoz Camacho, M. Mazouz, A. Deur, M. Brossard, M. Mihovilovic, D. Wang, S. Frullani, Vincent Sulkosky, R. Paremuzyan, E. Fuchey, R. A. Lindgren, S. Riordan, Franco Meddi, C. Desnault, H. Albataineh, D. Flay, J. Roche, Bogdan Wojtsekhowski, S. Chandavar, P. Bertin, C. W. de Jager, K. A. Aniol, R. Subedi, D. G. Meekins, P. Zhu, Z. Ahmed, L. El Fassi, W. U. Boeglin, E. Long, J. Gomez, O. Glamazdin, Olfred Hansen, A. Martí Jiménez-Argüello, Yujie Qiang, Andrew Puckett, X. Zheng, David Gaskell, Z. W. Zhao, Z. Ye, M. Magne, Charles Hyde, N. Nuruzzaman, S. Golge, 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), 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), 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), 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, Photon, 010308 nuclear & particles physics, Scattering, High Energy Physics::Phenomenology, Nuclear Theory, Compton scattering, FOS: Physical sciences, General Physics and Astronomy, Virtual particle, Parton, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, Isospin, 0103 physical sciences, 25.30.-c, 13.60.Fz, 13.85.Hd, 14.20.Dh, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), 010306 general physics, Nucleon, Nuclear Experiment
Abstract

The present experiment exploits the interference between the Deeply Virtual Compton Scattering (DVCS) and the Bethe-Heitler processes to extract the imaginary part of DVCS amplitudes on the neutron and on the deuteron from the helicity-dependent D$({\vec e},e'\gamma)X$ cross section measured at $Q^2$=1.9 GeV$^2$ and $x_B$=0.36. We extract a linear combination of generalized parton distributions (GPDs) particularly sensitive to $E_q$, the least constrained GPD. A model dependent constraint on the contribution of the up and down quarks to the nucleon spin is deduced., Comment: Published in Phys. Rev. Lett

Published
2007

14. A glimpse of gluons through deeply virtual compton scattering on the proton.

Author

Defurne M, Jiménez-Argüello AM, Ahmed Z, Albataineh H, Allada K, Aniol KA, Bellini V, Benali M, Boeglin W, Bertin P, Brossard M, Camsonne A, Canan M, Chandavar S, Chen C, Chen JP, de Jager CW, de Leo R, Desnault C, Deur A, El Fassi L, Ent R, Flay D, Friend M, Fuchey E, Frullani S, Garibaldi F, Gaskell D, Giusa A, Glamazdin O, Golge S, Gomez J, Hansen O, Higinbotham D, Holmstrom T, Horn T, Huang J, Huang M, Hyde CE, Iqbal S, Itard F, Kang H, Kelleher A, Keppel C, Koirala S, Korover I, LeRose JJ, Lindgren R, Long E, Magne M, Mammei J, Margaziotis DJ, Markowitz P, Mazouz M, Meddi F, Meekins D, Michaels R, Mihovilovic M, Camacho CM, Nadel-Turonski P, Nuruzzaman N, Paremuzyan R, Puckett A, Punjabi V, Qiang Y, Rakhman A, Rashad MNH, Riordan S, Roche J, Russo G, Sabatié F, Saenboonruang K, Saha A, Sawatzky B, Selvy L, Shahinyan A, Sirca S, Solvignon P, Sperduto ML, Subedi R, Sulkosky V, Sutera C, Tobias WA, Urciuoli GM, Wang D, Wojtsekhowski B, Yao H, Ye Z, Zhan X, Zhang J, Zhao B, Zhao Z, Zheng X, and Zhu P

Abstract

The internal structure of nucleons (protons and neutrons) remains one of the greatest outstanding problems in modern nuclear physics. By scattering high-energy electrons off a proton we are able to resolve its fundamental constituents and probe their momenta and positions. Here we investigate the dynamics of quarks and gluons inside nucleons using deeply virtual Compton scattering (DVCS)-a highly virtual photon scatters off the proton, which subsequently radiates a photon. DVCS interferes with the Bethe-Heitler (BH) process, where the photon is emitted by the electron rather than the proton. We report herein the full determination of the BH-DVCS interference by exploiting the distinct energy dependences of the DVCS and BH amplitudes. In the regime where the scattering is expected to occur off a single quark, measurements show an intriguing sensitivity to gluons, the carriers of the strong interaction.

Published
2017
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15. Rosenbluth Separation of the π^{0} Electroproduction Cross Section Off the Neutron.

Author

Mazouz M, Ahmed Z, Albataineh H, Allada K, Aniol KA, Bellini V, Benali M, Boeglin W, Bertin P, Brossard M, Camsonne A, Canan M, Chandavar S, Chen C, Chen JP, Defurne M, de Jager CW, de Leo R, Desnault C, Deur A, El Fassi L, Ent R, Flay D, Friend M, Fuchey E, Frullani S, Garibaldi F, Gaskell D, Giusa A, Glamazdin O, Golge S, Gomez J, Hansen O, Higinbotham D, Holmstrom T, Horn T, Huang J, Huang M, Huber GM, Hyde CE, Iqbal S, Itard F, Kang H, Kang H, Kelleher A, Keppel C, Koirala S, Korover I, LeRose JJ, Lindgren R, Long E, Magne M, Mammei J, Margaziotis DJ, Markowitz P, Martí Jiménez-Argüello A, Meddi F, Meekins D, Michaels R, Mihovilovic M, Muangma N, Muñoz Camacho C, Nadel-Turonski P, Nuruzzaman N, Paremuzyan R, Puckett A, Punjabi V, Qiang Y, Rakhman A, Rashad MNH, Riordan S, Roche J, Russo G, Sabatié F, Saenboonruang K, Saha A, Sawatzky B, Selvy L, Shahinyan A, Sirca S, Solvignon P, Sperduto ML, Subedi R, Sulkosky V, Sutera C, Tobias WA, Urciuoli GM, Wang D, Wojtsekhowski B, Yao H, Ye Z, Zana L, Zhan X, Zhang J, Zhao B, Zhao Z, Zheng X, and Zhu P

Abstract

We report the first longitudinal-transverse separation of the deeply virtual exclusive π^{0} electroproduction cross section off the neutron and coherent deuteron. The corresponding four structure functions dσ&#95;{L}/dt, dσ&#95;{T}/dt, dσ&#95;{LT}/dt, and dσ&#95;{TT}/dt are extracted as a function of the momentum transfer to the recoil system at Q^{2}=1.75  GeV^{2} and x&#95;{B}=0.36. The ed→edπ^{0} cross sections are found compatible with the small values expected from theoretical models. The en→enπ^{0} cross sections show a dominance from the response to transversely polarized photons, and are in good agreement with calculations based on the transversity generalized parton distributions of the nucleon. By combining these results with previous measurements of π^{0} electroproduction off the proton, we present a flavor decomposition of the u and d quark contributions to the cross section.

Published
2017
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16. Rosenbluth Separation of the π^{0} Electroproduction Cross Section.

Author

Defurne M, Mazouz M, Ahmed Z, Albataineh H, Allada K, Aniol KA, Bellini V, Benali M, Boeglin W, Bertin P, Brossard M, Camsonne A, Canan M, Chandavar S, Chen C, Chen JP, de Jager CW, de Leo R, Desnault C, Deur A, El Fassi L, Ent R, Flay D, Friend M, Fuchey E, Frullani S, Garibaldi F, Gaskell D, Giusa A, Glamazdin O, Golge S, Gomez J, Hansen O, Higinbotham D, Holmstrom T, Horn T, Huang J, Huang M, Huber GM, Hyde CE, Iqbal S, Itard F, Kang H, Kang H, Kelleher A, Keppel C, Koirala S, Korover I, LeRose JJ, Lindgren R, Long E, Magne M, Mammei J, Margaziotis DJ, Markowitz P, Martí Jiménez-Argüello A, Meddi F, Meekins D, Michaels R, Mihovilovic M, Muangma N, Muñoz Camacho C, Nadel-Turonski P, Nuruzzaman N, Paremuzyan R, Puckett A, Punjabi V, Qiang Y, Rakhman A, Rashad MN, Riordan S, Roche J, Russo G, Sabatié F, Saenboonruang K, Saha A, Sawatzky B, Selvy L, Shahinyan A, Sirca S, Solvignon P, Sperduto ML, Subedi R, Sulkosky V, Sutera C, Tobias WA, Urciuoli GM, Wang D, Wojtsekhowski B, Yao H, Ye Z, Zana L, Zhan X, Zhang J, Zhao B, Zhao Z, Zheng X, and Zhu P

Abstract

We present deeply virtual π^{0} electroproduction cross-section measurements at x&#95;{B}=0.36 and three different Q^{2} values ranging from 1.5 to 2  GeV^{2}, obtained from Jefferson Lab Hall A experiment E07-007. The Rosenbluth technique is used to separate the longitudinal and transverse responses. Results demonstrate that the cross section is dominated by its transverse component and, thus, is far from the asymptotic limit predicted by perturbative quantum chromodynamics. Nonetheless, an indication of a nonzero longitudinal contribution is provided by the measured interference term σ&#95;{LT}. Results are compared with several models based on the leading-twist approach of generalized parton distributions (GPDs). In particular, a fair agreement is obtained with models in which the scattering amplitude includes convolution terms of chiral-odd (transversity) GPDs of the nucleon with the twist-3 pion distribution amplitude. This experiment, together with previous extensive unseparated measurements, provides strong support to the exciting idea that transversity GPDs can be accessed via neutral pion electroproduction in the high-Q^{2} regime.

Published
2016
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17. Probing the repulsive core of the nucleon-nucleon interaction via the (4)He(e,e'pN) triple-coincidence reaction.

Author

Korover I, Muangma N, Hen O, Shneor R, Sulkosky V, Kelleher A, Gilad S, Higinbotham DW, Piasetzky E, Watson JW, Wood SA, Aguilera P, Ahmed Z, Albataineh H, Allada K, Anderson B, Anez D, Aniol K, Annand J, Armstrong W, Arrington J, Averett T, Badman T, Baghdasaryan H, Bai X, Beck A, Beck S, Bellini V, Benmokhtar F, Bertozzi W, Bittner J, Boeglin W, Camsonne A, Chen C, Chen JP, Chirapatpimol K, Cisbani E, Dalton MM, Daniel A, Day D, de Jager CW, De Leo R, Deconinck W, Defurne M, Flay D, Fomin N, Friend M, Frullani S, Fuchey E, Garibaldi F, Gaskell D, Gilman R, Glamazdin O, Gu C, Gueye P, Hamilton D, Hanretty C, Hansen JO, Hashemi Shabestari M, Holmstrom T, Huang M, Iqbal S, Jin G, Kalantarians N, Kang H, Khandaker M, LeRose J, Leckey J, Lindgren R, Long E, Mammei J, Margaziotis DJ, Markowitz P, Marti Jimenez-Arguello A, Meekins D, Meziani Z, Michaels R, Mihovilovic M, Monaghan P, Munoz Camacho C, Norum B, Nuruzzaman, Pan K, Phillips S, Pomerantz I, Posik M, Punjabi V, Qian X, Qiang Y, Qiu X, Rakhman A, Reimer PE, Riordan S, Ron G, Rondon-Aramayo O, Saha A, Schulte E, Selvy L, Shahinyan A, Sirca S, Sjoegren J, Slifer K, Solvignon P, Sparveris N, Subedi R, Tireman W, Wang D, Weinstein LB, Wojtsekhowski B, Yan W, Yaron I, Ye Z, Zhan X, Zhang J, Zhang Y, Zhao B, Zhao Z, Zheng X, Zhu P, and Zielinski R

Abstract

We studied simultaneously the (4)He(e,e'p), (4)He(e,e'pp), and (4)He(e,e'pn) reactions at Q(2)=2(GeV/c)(2) and x(B)>1, for an (e,e'p) missing-momentum range of 400 to 830  MeV/c. The knocked-out proton was detected in coincidence with a proton or neutron recoiling almost back to back to the missing momentum, leaving the residual A=2 system at low excitation energy. These data were used to identify two-nucleon short-range correlated pairs and to deduce their isospin structure as a function of missing momentum, in a region where the nucleon-nucleon (NN) force is expected to change from predominantly tensor to repulsive. The abundance of neutron-proton pairs is reduced as the nucleon momentum increases beyond ∼500  MeV/c. The extracted fraction of proton-proton pairs is small and almost independent of the missing momentum. Our data are compared with calculations of two-nucleon momentum distributions in (4)He and discussed in the context of probing the elusive repulsive component of the NN force.

Published
2014
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18. Search for a new gauge boson in electron-nucleus fixed-target scattering by the APEX experiment.

Author

Abrahamyan S, Ahmed Z, Allada K, Anez D, Averett T, Barbieri A, Bartlett K, Beacham J, Bono J, Boyce JR, Brindza P, Camsonne A, Cranmer K, Dalton MM, de Jager CW, Donaghy J, Essig R, Field C, Folts E, Gasparian A, Goeckner-Wald N, Gomez J, Graham M, Hansen JO, Higinbotham DW, Holmstrom T, Huang J, Iqbal S, Jaros J, Jensen E, Kelleher A, Khandaker M, LeRose JJ, Lindgren R, Liyanage N, Long E, Mammei J, Markowitz P, Maruyama T, Maxwell V, Mayilyan S, McDonald J, Michaels R, Moffeit K, Nelyubin V, Odian A, Oriunno M, Partridge R, Paolone M, Piasetzky E, Pomerantz I, Qiang Y, Riordan S, Roblin Y, Sawatzky B, Schuster P, Segal J, Selvy L, Shahinyan A, Subedi R, Sulkosky V, Stepanyan S, Toro N, Walz D, Wojtsekhowski B, and Zhang J

Abstract

We present a search at the Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling α' to electrons. Such a particle A' can be produced in electron-nucleus fixed-target scattering and then decay to an e + e- pair, producing a narrow resonance in the QED trident spectrum. Using APEX test run data, we searched in the mass range 175-250 MeV, found no evidence for an A'→ e+ e- reaction, and set an upper limit of α'/α ~/= 10(-6). Our findings demonstrate that fixed-target searches can explore a new, wide, and important range of masses and couplings for sub-GeV forces.

Published
2011
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