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1. An experimental program with high duty-cycle polarized and unpolarized positron beams at Jefferson Lab

Author: Anthony W. Thomas, M. Battaglieri, R. De Vita, D. Marchand, Latifa Elouadrhiri, S. Habet, Hubert Spiesberger, P. Gueye, David Hamilton, Giovanni Salmè, A. Filippi, Pete Markowitz, D. Perera, G. Kalicy, M. Muhoza, N. Kalantarians, H. Atac, M. Khandaker, J. Xie, F. Sabatié, M. Mazouz, Ashot Gasparian, I.P. Fernando, V. Klimenko, T. A. Forest, D. McNulty, Z. E. Meziani, M. Boer, M. McCaughan, A. Asaturyan, J. P. Chen, V. Kozhuharov, S. Stepanyan, Simonetta Liuti, T. Patel, Alberto Accardi, M. Spata, Andrew Puckett, Andreas Metz, Salina Ali, V. Bellini, L. Barion, V. V. Berdnikov, Alexandre Camsonne, P. E. Reimer, M. Shabestari, P. Bisio, Simon Širca, T. Averett, J. Kim, Nikolaos Sparveris, M. Poelker, M. Spreafico, H. F. Ibrahim, Dipangkar Dutta, V. Bertone, Bogdan Wojtsekhowski, Ross Milner, H. Avakian, C. E. Hyde, P. M. King, Marc Vanderhaeghen, A. Somov, Yulia Furletova, Miha Mihovilovič, V. Tadevosyan, P. Sznajder, S. Migliorati, R. S. Beminiwattha, T. Chetry, M. Guidal, Olfred Hansen, T. Kutz, Z. W. Zhao, Barbara Pasquini, Eric Voutier, L. Lanza, M. J. Amaryan, J. R. M. Annand, Fatiha Benmokhtar, T. Gautam, H. Voskanyan, Richard Trotta, Ian L. Pegg, J. F. Owens, W. J. Briscoe, Jingyi Zhou, P. Valente, M. N. H. Rashad, Gordan Krnjaic, P. Lenisa, Elena Santopinto, Joseph Grames, M. Leali, S. Zhamkochyan, M. Caudron, Kai-Thomas Brinkmann, Elton Smith, L. Marsicano, Andrei Afanasev, Luciano Pappalardo, M. Carmignotto, Donal Day, L. Venturelli, Eugene Pasyuk, M. Ungaro, C. Peng, L. Causse, D. Hasell, G. Costantini, Douglas Higinbotham, N. D’Hose, J. Murphy, P. Chatagnon, R. Dupré, M. Bondì, Alexander Ilyichev, Matteo Rinaldi, P. Stoler, Brian Raue, G. N. Grauvogel, R. Santos Estrada, Kondo Gnanvo, K. Price, Q. Liu, S. Diehl, J. Nazeer, Y. G. Sharabian, X. Zheng, S. Niccolai, P. G. Blunden, J. Arrington, Riad Suleiman, J. Erler, S. Joosten, Andrea Bianconi, H.-S. Ko, P. L. Cole, Nilanga Liyanage, I. Albayrak, K. Joo, Jan C. Bernauer, F.-X. Girod, D. Gaskell, A. Kim, Juliette Mammei, A. Italiano, M. Hattawy, C. Ayerbe Gayoso, I. I. Strakovsky, M. Yurov, N. Randazzo, A. Deur, Wally Melnitchouk, H.-G. Zaunick, Michael Kohl, A. D'Angelo, E. Nardi, M. Paolone, C. Zorn, L. El Fassi, B. T. Kriesten, L. Darmé, M. Rathnayake, A. Shahinyan, Jie Zhang, Alessandro Rizzo, D. Flay, W. Xiong, H. Dutrieux, V. Sergeyeva, S. Zhang, E. R. Kinney, Hervé Moutarde, B. Dongwi, Axel Schmidt, Rolf Ent, S. Zhao, Volker D. Burkert, A. S. Tadepalli, A. S. Biselli, Tanja Horn, G. Niculescu, T. Cao, A. Celentano, P. Nadel-Turonski, Ethan Cline, J. Roche, B. Karky, M. Contalbrigo, H. Szumila-Vance, S. Fucini, O. Rondon-Aramayo, M. De Napoli, V. Mascagna, E. Fuchey, L. Cardman, G. Ciullo, Haiyan Gao, Cynthia Keppel, M. Ehrhart, A. Movsisyan, R. Novotny, A. Hobart, Sergio Scopetta, B. McKinnon, S. A. Wood, H. Mkrtchyan, M. Tiefenback, C. Munoz Camacho, Xinzhan Bai, R. Paremuzyan, B. Sawatzky, D. Sokhan, M. Suresh, Markus Diefenthaler, Z. Ye, Mauro Raggi, M. Kerver, Y. Roblin, A. Mkrtchyan, V. P. Kubarovsky, R. Capobianco, T. J. Hague, Dustin Keller, Sonny Mantry, Vladimir Khachatryan, Peter Schweitzer, Michael Wood, Maxime Defurne, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: cross-section, ratio, Photon, parton distributions, elastic scattering, Parton, polarized beam, Electron, Leptons Accelerators, Structure of Nucleons, 7. Clean energy, 01 natural sciences, Dark photon, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), Positron, Economica, electromagnetic form-factors, virtual compton-scattering, generalized, squared 4-momentum transfers, lepton-flavor, violation, electron-proton, parity violation, pair production, Physics, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), Nuclear Experiment, Elastic scattering, Dark sector, JLab, dark photon, Settore FIS/04, lepton: flavor: violation, nucleon: generalized parton distribution, 3. Good health, High Energy Physics - Phenomenology, Elastic and deep inelastic Scattering, Nucleon, Jefferson Lab, Nuclear and High Energy Physics, nucleon: form factor: electromagnetic, FOS: Physical sciences, Socio-culturale, helium: target, Context (language use), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear physics, PE2_2, PE2_1, deeply virtual Compton scattering, 0103 physical sciences, quantum chromodynamics, 010306 general physics, PE2_3, activity report, exchange: two-photon, electroweak interaction, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Ambientale, positron: beam, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], charge: asymmetry, Positron Beams, Physics::Accelerator Physics, proposal, High Energy Physics::Experiment
Abstract: Positron beams, both polarized and unpolarized, are identified as essential ingredients for the experimental programs at the next generation of lepton accelerators. In the context of the hadronic physics program at Jefferson Lab (JLab), positron beams are complementary, even essential, tools for a precise understanding of the electromagnetic structure of nucleons and nuclei, in both the elastic and deep-inelastic regimes. For instance, elastic scattering of polarized and unpolarized electrons and positrons from the nucleon enables a model independent determination of its electromagnetic form factors. Also, the deeply-virtual scattering of polarized and unpolarized electrons and positrons allows unambiguous separation of the different contributions to the cross section of the lepto-production of photons and of lepton-pairs, enabling an accurate determination of the nucleons and nuclei generalized parton distributions, and providing an access to the gravitational form factors. Furthermore, positron beams offer the possibility of alternative tests of the Standard Model of particle physics through the search of a dark photon, the precise measurement of electroweak couplings, and the investigation of charged lepton flavor violation. This document discusses the perspectives of an experimental program with high duty-cycle positron beams at JLab., Comment: 18 pages, 7 figures This version superseeds the previous version which scientific content was decomposed into several more elaborated articles. All of these articles will be collected in the EPJ A Topical Issue about "Positron beam and physics at Jefferson Lab (e+@Jlab)"
Published: 2021
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2. Measurement of the 3He spin-structure functions and of neutron (3He) spin-dependent sum rules at 0.035 ≤ Q2 ≤ 0.24 GeV2

Author: Wolfgang Korsch, P.Y. Bertin, A. Shabetai, N. Kolb, Pete Markowitz, Houbing Lu, T.B. Humensky, K. Kramer, R. Roche, Z. E. Meziani, R. De Leo, Antonin Vacheret, Ronald Ransome, Jaideep Singh, R. J. Feuerbach, M. Iodice, F. Garibaldi, W. U. Boeglin, Nilanga Liyanage, L. J. Kaufman, X. Zhan, J. Yuan, J. Gomez, L. Zhu, R. Stringer, L. Wan, Seung-Tae Woo, H. F. Ibrahim, D. Hayes, L. Lagamba, J. Niedziela, Ronald Pandolfi, Douglas Higinbotham, A.J.R. Puckett, S. Dhamija, K. McCormick, S. L. Bailey, Bogdan Wojtsekhowski, J. P. Chen, V. Laine, E. Chudakov, X. Zheng, S. Frullani, P. Monaghan, S. K. Nanda, B. Craver, Yujie Qiang, G. J. Kumbartzki, D. S. Armstrong, J. O. Hansen, P. E. Ulmer, N. Ton, K. E. Keister, G. Laveissière, J. M. Finn, Simon Širca, B. Ma, K. Wang, B. Hersman, R. A. Lindgren, J. J. LeRose, M. Niskin, A. Saha, A. Kelleher, Karl Slifer, V. Sulkosky, F. Cusanno, Seonho Choi, S. Abrahamyan, Ronald Gilman, A. Deur, A. V. Glamazdin, A. Camsonne, D. Lhuillier, J. C. Cornejo, P. Solvignon, R. Subedi, A. Kolarkar, A. Beck, T. Averett, C. E. Hyde, Kent Paschke, Charles Glashausser, V. A. Punjabi, W. Kim, Haiyan Gao, E. Voutier, M. Potokar, L. Coman, J. D. Denton, B. Reitz, C. C. Chang, Olivier Gayou, K. Fuoti, X. Jiang, D. J. Margaziotis, C. Peng, H. Yao, G. D. Cates, William A. Tobias, R. Snyder, G. M. Urciuoli, C. W. de Jager, K. A. Aniol, Bryan J. Moffit, T. Holmstrom, M. Meziane, F. Butaru, R. Michaels, 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), Département de Physique Nucléaire (ex SPhN) (DPHN), 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 Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Jefferson Lab E97-110, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), 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)-Université Grenoble Alpes (UGA), and E97-110
Subjects: Nuclear and High Energy Physics, n: polarization, Electron, structure function: spin, Spin structure, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], spin: dependence, 01 natural sciences, High Energy Physics - Experiment, 0103 physical sciences, Effective field theory, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Neutron, helium: polarization, 010306 general physics, Nuclear Experiment, Spin-½, Physics, Quantum chromodynamics, 010308 nuclear & particles physics, deuteron: structure function, cross section: difference, Resonance, Observable, perturbation theory: chiral, lcsh:QC1-999, sum rule: spin, Atomic physics, spin: asymmetry, lcsh:Physics, experimental results, Jefferson Lab
Abstract: The spin-structure functions $g_1$ and $g_2$, and the spin-dependent partial cross-section $\sigma_\mathrm{TT}$ have been extracted from the polarized cross-sections differences, $\Delta \sigma_{\parallel}\hspace{-0.06cm}\left(\nu,Q^{2}\right)$ and $\Delta \sigma_{\perp}\hspace{-0.06cm}\left(\nu,Q^{2}\right)$ measured for the $\vec{^\textrm{3}\textrm{He}}(\vec{\textrm{e}},\textrm{e}')\textrm{X}$ reaction, in the E97-110 experiment at Jefferson Lab. Polarized electrons with energies from 1.147 to 4.404 GeV were scattered at angles of 6$^{\circ}$ and 9$^{\circ}$ from a longitudinally or transversely polarized $^{3}$He target. The data cover the kinematic regions of the quasi-elastic, resonance production and beyond. From the extracted spin-structure functions, the first moments $\overline{\Gamma_1}\hspace{-0.06cm}\left(Q^{2}\right)$, $\Gamma_2\hspace{-0.06cm}\left(Q^{2}\right)$ and $I_{\mathrm{TT}}\hspace{-0.06cm}\left(Q^{2}\right)$ are evaluated with high precision for the neutron in the $Q^2$ range from 0.035 to 0.24~GeV$^{2}$. The comparison of the data and the chiral effective field theory predictions reveals the importance of proper treatment of the $\Delta$ degree of freedom for spin observables., Comment: 7 pages, 5 figures, 3 tables. Version published in Phys. Lett. B
Published: 2020
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3. Comparing proton momentum distributions in A = 2 and 3 nuclei via 2H 3H and 3He (e,e′p) measurements

Author: Z. Ye, B. Schmookler, J. P. Chen, G. M. Urciuoli, Diego Lonardoni, P. M. King, Hongbang Liu, R. Michaels, D. King, M. Olson, Darko Androić, S. Covrig, Toshiyuki Gogami, Pete Markowitz, S. Paul, Weidong Li, M. Viviani, Whitney Armstrong, P. E. Reimer, Larry Weinstein, T. Su, M. Patsyuk, H. Atac, B. Dongwi, Or Hen, N. Santiesteban, B. Sawatzky, T. Kutz, V. Bellini, R. I. Pomatsalyuk, H. Bhatt, I. Korover, S. A. Wood, R. Obrecht, S. Riordan, V. Pandey, E. Fuchey, Shanfeng Li, A. Beck, M. Hattawy, John Arrington, S. Mey-Tal Beck, Andrew Puckett, D. Bulumulla, Bogdan Wojtsekhowski, Aditya R. Khanal, F. Hauenstein, Simon Širca, A. Shahinyan, M. N. H. Rashad, Axel Schmidt, Cynthia Keppel, M. Khachatryan, J. Gomez, N. Lashley-Colthirst, D. Blyth, J. Castellanos, Ruprecht Machleidt, R. Suleiman, H. Albataineh, D. Bhetuwal, V. Khachatryan, Kondo Gnanvo, Eliahu Cohen, F. Tortorici, J. Roche, V. A. Punjabi, N. Nuruzzaman, S. Alsalmi, M. Nycz, H. Szumila-Vance, B. Duran, G. G. Petratos, Z. E. Meziani, C. Gal, Vladimir Nelyubin, G. Laskaris, L. Tang, W. Tireman, M. Mihovilovic, A. Karki, Ronald Ransome, D. G. Meekins, A. T. Katramatou, Olfred Hansen, W. U. Boeglin, Nilanga Liyanage, D. Biswas, C. Ayerbe Gayoso, Jiawen Zhang, S. Premathilake, D. Nguyen, X. Bai, E.P. Segarra, Siyu Jian, Elliot Hughes, R. Cruz-Torres, Douglas Higinbotham, L. Ou, S. Barcus, V. Owen, J. Bane, A. S. Tadepalli, R. E. McClellan, A. Habarakada, Sylvester Joosten, K. Craycraft, H. F. Ibrahim, B. Karki, Dipangkar Dutta, Laura Elisa Marcucci, M. Duer, T. Gautam, B. Pandey, Shalev Gilad, A. Papadopoulou, K. A. Aniol, A. Camsonne, D. Abrams, S. Park, F. Sammarruca, N. Sparveris, E. Piasetzky, C. Gu, T. Hague, T. Averett, and C. E. Hyde
Subjects: production [pi], Nuclear and High Energy Physics, data analysis method, Photon, Nuclear Theory, interference, FOS: Physical sciences, Electron, Impulse (physics), Inelastic scattering, 01 natural sciences, xperimental results | Jefferson Lab | electron p: scattering | parity: violation | inelastic scattering | structure function | interference | photon | Z0 | pi: production | spin: asymmetry | data analysis method, Nuclear Theory (nucl-th), structure function, 0103 physical sciences, Z0, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Physics, 010308 nuclear & particles physics, Momentum transfer, photon, inelastic scattering, scattering [electron p], Eikonal approximation, NATURAL SCIENCES. Physics, lcsh:QC1-999, PRIRODNE ZNANOSTI. Fizika, Deuterium, xperimental results, High Energy Physics::Experiment, violation [parity], Atomic physics, Nucleon, asymmetry [spin], lcsh:Physics, Jefferson Lab
Abstract: We report the first measurement of the $(e,e'p)$ reaction cross-section ratios for Helium-3 ($^3$He), Tritium ($^3$H), and Deuterium ($d$). The measurement covered a missing momentum range of $40 \le p_{miss} \le 550$ MeV$/c$, at large momentum transfer ($\langle Q^2 \rangle \approx 1.9$ (GeV$/c$)$^2$) and $x_B>1$, which minimized contributions from non quasi-elastic (QE) reaction mechanisms. The data is compared with plane-wave impulse approximation (PWIA) calculations using realistic spectral functions and momentum distributions. The measured and PWIA-calculated cross-section ratios for $^3$He$/d$ and $^3$H$/d$ extend to just above the typical nucleon Fermi-momentum ($k_F \approx 250$ MeV$/c$) and differ from each other by $\sim 20\%$, while for $^3$He/$^3$H they agree within the measurement accuracy of about 3\%. At momenta above $k_F$, the measured $^3$He/$^3$H ratios differ from the calculation by $20\% - 50\%$. Final state interaction (FSI) calculations using the generalized Eikonal Approximation indicate that FSI should change the $^3$He/$^3$H cross-section ratio for this measurement by less than 5\%. If these calculations are correct, then the differences at large missing momenta between the $^3$He/$^3$H experimental and calculated ratios could be due to the underlying $NN$ interaction, and thus could provide new constraints on the previously loosely-constrained short-distance parts of the $NN$ interaction., 8 pages, 3 figures (4 panels)
Published: 2019

4. 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
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5. Measurement of double-polarization asymmetries in the quasi-elastic Process

Author: R. A. Lindgren, C. Dutta, William A. Tobias, X. Zhan, F. Garibaldi, M. H. Shabestari, G. D. Cates, D. Flay, B. Schoenrock, Henryk Witała, Y. Zhang, X. Deng, Diana Parno, T. Holmstrom, J. P. Chen, B. Zhao, P. Monaghan, Yingxiao Wang, J. Huang, P. M. King, A. Saha, G. M. Urciuoli, Bogdan Wojtsekhowski, N. Muangma, J. Gomez, Shalev Gilad, S. Golge, R. Subedi, C. W. de Jager, T. Averett, Chunhui Chen, S. Širca, A. Shahinyan, P. C. Bradshaw, X. Jiang, Xin Qian, A. Kievsky, J. St. John, P. U. Sauer, H. P. Khanal, B. Moffit, Mustafa Canan, Kalyan Allada, R. Michaels, R. Skibiński, L. El Fassi, W. U. Boeglin, A. Deltuva, A. Deur, H. Kang, B. D. Anderson, Yiyang Zhang, W. Tireman, M. Meziane, M. Posik, William Bertozzi, Z. Ye, H.-J. Lu, Wolfgang Korsch, B. E. Norum, Michele Viviani, Hiroyuki Kamada, Vincent Sulkosky, O. Glamazdin, Pete Markowitz, Olfred Hansen, J. R. M. Annand, A. Camsonne, H. F. Ibrahim, J. LeRose, W. Luo, R. De Leo, Joseph M. Katich, Kacper Topolnicki, J. W. Watson, B. Sawatzky, E. Chudakov, Haiyan Gao, L. E. Marcucci, S. Riordan, V. A. Punjabi, D. Wang, Ronald Gilman, Douglas Higinbotham, M. K. Jones, E. Jensen, Jacek Golak, K. Pan, K. Wang, X. Qui, L. Y. Zhu, S. Frullani, G. Jin, X. Zheng, S. K. Nanda, Yujie Qiang, Andrew Puckett, Rocco Schiavilla, E. Long, M. Mihovilovič, and E. Piasetzky
Subjects: Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Nuclear Theory, Observable, Kinematics, Spin structure, Polarization (waves), Breakup, 01 natural sciences, p-process, Nuclear interaction, Nuclear physics, Reaction dynamics, 0103 physical sciences, Nuclear Experiment, 010306 general physics
Abstract: We report on a precise measurement of double-polarization asymmetries in electron-induced breakup of He3 proceeding to pd and ppn final states, performed in quasi-elastic kinematics at Q2=0.25(GeV/c)2 for missing momenta up to 250MeV/c. These observables represent highly sensitive tools to investigate the electromagnetic and spin structure of He3 and the relative importance of two- and three-body effects involved in the breakup reaction dynamics. The measured asymmetries cannot be satisfactorily reproduced by state-of-the-art calculations of He3 unless their three-body segment is adjusted, indicating that the spin-dependent part of the nuclear interaction governing the three-body breakup process is much smaller than previously thought.
Published: 2018

6. Measurement of the doubly-polarized He3→(γ→,n)pp reaction at 16.5 MeV and its implications for the GDH sum rule

Author: M. Meziane, X. Yan, J.N. Heideman, M. W. Ahmed, P. H. Chu, W. Xiong, Jacek Golak, T. Averett, Henryk Witała, G. Laskaris, H. R. Weller, I. I. Strakovsky, W.R. Zimmerman, A. Deltuva, R. Skibiński, C. Flower, A. C. Fonseca, Jonathan Mueller, P. U. Sauer, Ying Wu, Haiyan Gao, and Hugon J Karwowski
Subjects: Physics, Nuclear and High Energy Physics, High intensity, Nuclear Theory, Polarization observables, Photon energy, Standard deviation, Nuclear physics, Cross section (physics), Photodisintegration, Coulomb, Sum rule in quantum mechanics, Atomic physics, Nuclear Experiment
Abstract: We report new measurements of the double-polarized photodisintegration of 3 He at an incident photon energy of 16.5 MeV, carried out at the High Intensity γ -ray Source (HI γ S) facility located at Triangle Universities Nuclear Laboratory (TUNL). The spin-dependent double-differential cross sections and the contribution from the three-body channel to the Gerasimov–Drell–Hearn (GDH) integrand were extracted and compared with the state-of-the-art three-body calculations. The calculations, which include the Coulomb interaction and are in good agreement with the results of previous measurements at 12.8 and 14.7 MeV, deviate from the new cross section results at 16.5 MeV. The GDH integrand was found to be about one standard deviation larger than the maximum value predicted by the theories.
Published: 2015
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7. Precision measurements of A1n in the deep inelastic regime

Author: S. Choi, Mustafa Canan, Kalyan Allada, H. Yao, M. Friend, A. Deur, Wouter Deconinck, Nuruzzaman, J. P. Chen, B. Sawatzky, F. Garibaldi, M. H. Shabestari, G. D. Cates, S. K. Nanda, Yujie Qiang, R. Subedi, A. Camsonne, N. Muangma, A. Shahinyan, Vincent Sulkosky, O. Glamazdin, Z. Ye, B. E. Norum, V. Mamyan, J. Huang, R. A. Lindgren, J. J. LeRose, Olfred Hansen, Bogdan Wojtsekhowski, X. Deng, X. Zhan, W. Troth, Y. Zhang, D. Flay, A. Lukhanin, B. Moffit, G. Jin, M. Posik, Douglas Higinbotham, C. Dutta, X. Zheng, Zein-Eddine Meziani, Diana Parno, William A. Tobias, D. McNulty, Arijit Saha, P. Solvignon, J. Gomez, Jen-Chieh Peng, S. Golge, Chunhui Chen, S. Širca, Haiyan Gao, Y. X. Ye, Wolfgang Korsch, L. Yuan, X. Jiang, Whitney Armstrong, G. Kumbartzki, B. Zhao, Yiyang Zhang, William Bertozzi, Yingxiao Wang, Amrendra Narayan, Joseph M. Katich, Shalev Gilad, C. W. de Jager, G. B. Franklin, M. M. Dalton, T. Holmstrom, S. Riordan, D. Wang, Ronald Gilman, R. Michaels, Abdurahim Rakhman, L. Guo, E. Long, M. Mihovilovič, A. Kelleher, Vladimir Nelyubin, Young Do Oh, H. F. Ibrahim, E. Chudakov, A. Kolarkar, Nilanga Liyanage, T. Averett, C. E. Hyde, F. Cusanno, Fatiha Benmokhtar, X. Yan, Xin Qian, and L. El Fassi
Subjects: Quantum chromodynamics, Physics, Nuclear physics, Quark, Nuclear and High Energy Physics, Proton, media_common.quotation_subject, Up quark, Neutron, Parton, Deep inelastic scattering, Asymmetry, media_common
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 and a longitudinally and transversely polarized 3 He target. Our data cover a wide kinematic range 0.277 ≤ x ≤ 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 make a leading-order extraction of 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 ( Δ d + Δ d ¯ ) / ( d + d ¯ ) up to x = 0.548 .
Published: 2015
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8. 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
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9. 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, O. Glamazdin, J. R. M. Annand, J. P. Chen, S. K. Nanda, Yujie Qiang, A. Kelleher, J. Huang, M. Mihovilovič, A. Deur, T. Holmstrom, F. Garibaldi, Z. Ye, B. E. Norum, William Bertozzi, Pete Markowitz, M. H. Shabestari, L. Y. Zhu, J. Gomez, X. Jiang, B. Zhao, R. De Leo, X. Deng, S. Riordan, P. Monaghan, A. Shahinyan, Y. Zhang, T. Averett, Xin Qian, G. Jin, Chunhui Chen, S. Širca, J. St. John, M. Meziane, A. Camsonne, B. D. Anderson, X. Zheng, B. Moffit, H. F. Ibrahim, B. Sawatzky, H.-J. Lu, B. Shoenrock, S. Golge, L. El Fassi, W. U. Boeglin, Wolfgang Korsch, P. M. King, Vincent Sulkosky, E. Chudakov, R. Subedi, C. Dutta, William A. Tobias, J. O. Hansen, V. A. Punjabi, Bogdan Wojtsekhowski, J. W. Watson, X. Qui, N. Muangma, R. Michaels, H. P. Khanal, W. Tireman, G. D. Cates, X. Zhan, Yingxiao Wang, H. Kang, S. Frullani, G. M. Urciuoli, M. Posik, Shalev Gilad, R. A. Lindgren, J. J. LeRose, C. W. de Jager, W. Luo, Diana Parno, A. J. R. Puckett, D. Flay, Haiyan Gao, D. Wang, E. Piasetzky, Ronald Gilman, Mustafa Canan, Kalyan Allada, Yiyang Zhang, Joseph M. Katich, Douglas Higinbotham, A. Saha, M. K. Jones, P. C. Bradshaw, E. Jensen, K. Pan, and K. Wang
Subjects: Physics, Nuclear reaction, Nuclear and High Energy Physics, Meson, 010308 nuclear & particles physics, Scattering, media_common.quotation_subject, Plane wave, Electron, 01 natural sciences, Asymmetry, Nuclear physics, 0103 physical sciences, Neutron, Nuclear Experiment, 010306 general physics, Electron scattering, media_common
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 A y 0 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 A y 0 at Q 2 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 Q 2 = 0.46 (GeV/ c ) 2 to nearly zero at Q 2 = 0.96 (GeV / c ) 2 , demonstrating the fall-off of the reaction mechanism effects as Q 2 increases. We also observed a small ϵ-dependent increase in A y 0 compared to previous measurements, particularly at moderate Q 2 . This indicates that upcoming high Q 2 measurements from the Jefferson Lab 12 GeV program can cleanly probe neutron structure from polarized 3He using plane wave impulse approximation.
Published: 2019
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10. The ${Q^{p}_{\rm Weak}}$ experiment

Author: P. Solvignon, Wouter Deconinck, Riad Suleiman, D. G. Meekins, V. M. Gray, M. Poelker, J. A. Magee, S. Yang, S. Wells, Amrendra Narayan, R. T. Jones, T. Averett, B. Waidyawansa, D. Gaskell, Jean-Francois Rajotte, K. E. Myers, S. Kowalski, W. S. Duvall, William A. Tobias, M. K. Jones, W. T. H. van Oers, J. W. Martin, F. Guo, Joseph Grames, W. R. Falk, Kent Paschke, K. Grimm, J. Balewski, D. S. Armstrong, G. R. Smith, S. Covrig, J. A. Dunne, K. Johnston, V. Tadevosyan, P. Wang, Fatiha Benmokhtar, J. Mei, Vladimir Nelyubin, T. A. Forest, M. Kargiantoulakis, J. Leacock, J.C. Cornejo, M. M. Dalton, A.K. Opper, A. Mkrtchyan, Darko Androić, R. Silwal, V. Tvaskis, M. J. McHugh, W. D. Ramsay, L. Lee, Neven Simicevic, P. M. King, R. Mahurin, R. S. Beminiwattha, Michael Gericke, D. Zou, S. Zhamkochyan, J. Diefenbach, N. Nuruzzaman, Dipangkar Dutta, Roger Carlini, S. K. Phillips, D. T. Spayde, A. M. Micherdzinska, S. A. Page, M. H. Shabestari, J. R. Hoskins, D. C. Jones, Michael Pitt, Ross D. Young, Jongmin Lee, J. Birchall, Jay Benesch, K. A. Dow, L. Z. Ndukum, J. F. Dowd, A. R. Lee, Juliette Mammei, R. Michaels, J. M. Finn, J. Pan, J. Leckey, A. Asaturyan, A. Subedi, S. A. Wood, M. Elaasar, H. Mkrtchyan, C. A. Davis, D. J. Mack, S. MacEwan, T. Seva, E. Korkmaz, B. Sawatzky, J. Beaufait, R. Subedi, and J. Roche
Subjects: Quark, Physics, Nuclear and High Energy Physics, Particle physics, Proton, media_common.quotation_subject, Physics beyond the Standard Model, Momentum transfer, Weinberg angle, Parity (physics), Electron, Condensed Matter Physics, Asymmetry, Atomic and Molecular Physics, and Optics, Nuclear physics, Physical and Theoretical Chemistry, media_common
Abstract: In May 2012, the $Q^{p}_{\rm Weak}$ collaboration completed a two year measurement program to determine the weak charge of the proton ${Q^{p}_W} = ( 1 - 4\sin^2{\theta_{W}})$ at the Thomas Jefferson National Accelerator Facility (TJNAF). The experiment was designed to produce a 4.0 % measurement of the weak charge, via a 2.5 % measurement of the parity violating asymmetry in the number of elastically scattered 1.165 GeV electrons from protons, at forward angles. At the proposed precision, the experiment would produce a 0.3 % measurement of the weak mixing angle at a momentum transfer of Q 2 = 0.026 GeV2, making it the most precise stand alone measurement of the weak mixing angle at low momentum transfer. In combination with other parity measurements, $Q^{p}_{\rm Weak}$ will also provide a high precision determination of the weak charges of the up and down quarks. At the proposed precision, a significant deviation from the Standard Model prediction could be a signal of new physics at mass scales up to ≃ 6 TeV, whereas agreement would place new and significant constraints on possible Standard Model extensions at mass scales up to ≃ 2 TeV. This paper provides an overview of the physics and the experiment, as well as a brief look at some preliminary diagnostic and analysis data.
Published: 2013
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11. The tracking analysis in the Q-weak experiment

Author: T. Averett, M. M. Dalton, A.K. Opper, W. D. Ramsay, D. T. Spayde, K. Johnston, Kent Paschke, J. Mei, J.C. Cornejo, William A. Tobias, F. Guo, P. M. King, W. R. Falk, Vladimir Nelyubin, S. A. Wood, R. Mahurin, J. Leacock, Fatiha Benmokhtar, D. J. Mack, Jean-Francois Rajotte, S. A. Page, D. G. Meekins, J. Pan, Michael Gericke, S. Wells, S. Kowalski, J. Balewski, W. S. Duvall, J. Leckey, R. T. Jones, A. Mkrtchyan, M. H. Shabestari, J. W. Martin, Nuruzzaman, M. Elaasar, C. A. Davis, L. Z. Ndukum, B. Sawatzky, M. Kargiantoulakis, J. Grames, J. A. Magee, Roger Carlini, S. K. Phillips, P. Solvignon, G. D. Cates, S. Yang, Jongmin Lee, D. C. Jones, J. Diefenbach, N. Morgan, Wouter Deconinck, W. T. H. van Oers, Darko Androić, R. Michaels, V. M. Gray, A. R. Lee, B. Waidyawansa, S. MacEwan, T. Seva, E. Korkmaz, Jay Benesch, V. Tvaskis, J. Beaufait, R. Subedi, A. Asaturyan, R. Suleiman, S. Zhamkochyan, K. E. Myers, H. Mkrtchyan, D. S. Armstrong, G. R. Smith, J. A. Dunne, P. Wang, L. Lee, Dipangkar Dutta, K. Grimm, A. Subedi, S. Covrig, M. J. McHugh, Michael Pitt, Neven Simicevic, J. M. Finn, J. R. Hoskins, J. Roche, J. Birchall, T. A. Forest, Juliette Mammei, A. Micherdzinska, V. Tadevosyan, M. K. Jones, R. Silwal, Amrendra Narayan, M. Poelker, D. Gaskell, R. S. Beminiwattha, Ross D. Young, and J. F. Dowd
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Spectrometer, business.industry, Scattering, media_common.quotation_subject, Momentum transfer, Tracking system, Parity (physics), Kinematics, Electron, Condensed Matter Physics, 01 natural sciences, Asymmetry, Atomic and Molecular Physics, and Optics, 010305 fluids & plasmas, Nuclear physics, q-weak experiment, 0103 physical sciences, Physical and Theoretical Chemistry, 010306 general physics, business, Nuclear Experiment, media_common
Abstract: The Q-weak experiment at Jefferson Laboratory measured the parity violating asymmetry (A P V ) in elastic electron-proton scattering at small momentum transfer squared (Q 2=0.025 (G e V/c)2), with the aim of extracting the proton’s weak charge ( ${Q^p_W}$ ) to an accuracy of 5 %. As one of the major uncertainty contribution sources to ${Q^p_W}$ , Q 2 needs to be determined to ∼1 % so as to reach the proposed experimental precision. For this purpose, two sets of high resolution tracking chambers were employed in the experiment, to measure tracks before and after the magnetic spectrometer. Data collected by the tracking system were then reconstructed with dedicated software into individual electron trajectories for experimental kinematics determination. The Q-weak kinematics and the analysis scheme for tracking data are briefly described here. The sources that contribute to the uncertainty of Q 2 are discussed, and the current analysis status is reported.
Published: 2016

12. A high-pressure polarized 3He gas target for the High Intensity Gamma Source (HIS) facility at Duke Free Electron Laser Laboratory

Author: T. Averett, Xin Qian, Xing Zong, K. Kramer, Dipangkar Dutta, Sabine Fuchs, Xiaofeng Zhu, Haiyan Gao, Rongchun Lu, and Q. Ye
Subjects: Physics, Nuclear and High Energy Physics, Photon, Free-electron laser, Particle accelerator, Polarization (waves), law.invention, Optical pumping, law, Cathode ray, Neutron, Atomic physics, Electron paramagnetic resonance, Instrumentation
Abstract: A new polarized 3 He target has been developed for nuclear physics experiments utilizing the High Intensity Gamma Source (HI γ S) at the Duke Free Electron Laser Laboratory (DFELL). This target is designed for a broad program of physics employing high intensity polarized photons and a polarized 3 He target as an effective polarized neutron target. We report the performance of this target based on the technique of spin-exchange optical pumping (SEOP). Due to the significantly larger photon beam size at the HI γ S facility than that of a typical electron beam at electron accelerator laboratories, the HI γ S 3 He target contains a larger number of 3 He nuclei than any polarized 3 He targets reported previously. A target polarization on the order of 33–46% has been achieved from both a regular 3 He–Rubidium (Rb) target and a hybrid target which contains a mixture of Rb and potassium. The target polarization has been determined within 3 % using both the Electron Paramagnetic Resonance (EPR) technique and the NMR–AFP (Adiabatic Fast Passage) technique.
Published: 2007
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13. The low Q2 behavior of the extended Gerasimov-Drell-Hearn sum rule

Author: T. Averett
Subjects: Physics, Nuclear and High Energy Physics, Rule of sum, Sum rule in quantum mechanics, Mathematical physics
Published: 2007
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14. Moments of the neutrong2structure function at intermediateQ2

Author: Bogdan Wojtsekhowski, D. J. Margaziotis, H. F. Ibrahim, K. Kramer, Dipangkar Dutta, Olfred Hansen, E. Chudakov, X. Jiang, R. J. Feuerbach, P. Monaghan, B. Craver, C. C. Chang, K. Wijesooriya, R. Shneor, C. Muñoz Camacho, G. D. Cates, V. Sulkosky, Karl Slifer, F. Garibaldi, W. U. Boeglin, Nilanga Liyanage, K. A. Aniol, Bryan J. Moffit, L. Zhu, K. McCormick, R. Michaels, B. Reitz, A. Saha, X. Zheng, James J. Kelly, S. Frullani, Seung-Tae Woo, P. Solvignon, B. Ma, Pete Markowitz, A. Kelleher, J. P. Chen, G. M. Urciuoli, A. Tobias, F. Cusanno, A. Deur, Wolfgang Korsch, Jaideep Singh, Cynthia Keppel, Douglas Higinbotham, M. K. Jones, W. Kim, K. Wang, Seonho Choi, Ronald Gilman, G. J. Kumbartzki, Rolf Ent, Haiyan Gao, Z. E. Meziani, A. Camsonne, R. A. Lindgren, J. J. LeRose, T. Averett, V. Gorbenko, Kent Paschke, Charles Glashausser, and J. C. Yang
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, Structure function, High Energy Physics::Experiment, Neutron, Sum rule in quantum mechanics, Lattice QCD, Function (mathematics), Spin structure, Nuclear Experiment, Resonance (particle physics), Spin-½
Abstract: We present new experimental results of the ³He spin structure function g₂ in the resonance region at Q² values between 1.2 and 3.0 (GeV/c)². Spin dependent moments of the neutron were then extracted.Our main result, the inelastic contribution to the neutron d₂ matrix element, was found to be small (Q²) = 2.4 (GeV/c)² and in agreement with the Lattice QCD calculation. The Burkhardt-Cottingham sum rule for ³He neutron was tested with the measured data and using the Wandzura-Wilczek relation for the low x unmeasured region.
Published: 2015
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15. Double spin asymmetries of inclusive hadron electroproduction from a transversely polarizedHe3target

Author: S. K. Nanda, Yujie Qiang, H. Yao, M. M. Dalton, S. Riordan, Bogdan Wojtsekhowski, S. S. Stepanyan, Mustafa Canan, T. Holmstrom, Wolfgang Korsch, Kalyan Allada, J. C. Cornejo, L. G. Tang, Y. Zhang, D. McNulty, P. A. M. Dolph, T. Averett, Abdurahim Rakhman, M. Huang, Jen-Chieh Peng, X. Zong, S. K. Phillips, B. Sawatzky, X. Li, G. Jin, X. Zheng, C. Dutta, Nilanga Liyanage, Franco Garibaldi, L. Yuan, A. Camsonne, Chunhui Chen, B. Zhao, L. Guo, K. Chirapatpimol, Salvatore Frullani, Y. Li, D. J. Margaziotis, Simon Širca, Young Do Oh, Vincent Sulkosky, E. Long, Mauro Iodice, F. Cusanno, L. Y. Zhu, William A. Tobias, W. Kim, A. Deur, E. Cisbani, A. J. R. Puckett, J. P. Chen, Fatiha Benmokhtar, S. Golge, A. Kelleher, H. J. Lu, A. Shahinyan, R. A. Lindgren, J. J. LeRose, Yong Zhang, I. Vilardi, H. Ding, A. Kolarkar, Vladimir Nelyubin, J. Huang, G. M. Urciuoli, H. F. Ibrahim, E. Schulte, Xiaofeng Zhu, Dipangkar Dutta, R. Michaels, G. D. Cates, X. Zhan, E. Chudakov, M. Osipenko, William Bertozzi, Haiyan Gao, O. Glamazdin, Z. Ye, B. E. Norum, Diana Parno, S. Marrone, Olfred Hansen, J. R. M. Annand, Y. Zhao, David Hamilton, Pete Markowitz, A. Saha, M. H. Shabestari, P. Bosted, Y. X. Ye, R. De Leo, X. Yan, Ronald Ransome, Xin Qian, Yingxiao Wang, P. C. Bradshaw, M. Posik, X. Deng, Zein-Eddine Meziani, L. El Fassi, C. Muñoz Camacho, Shalev Gilad, C. W. de Jager, K. A. Aniol, Wouter Deconinck, R. Subedi, Amrendra Narayan, Joseph M. Katich, D. Gaskell, Ronald Gilman, Douglas Higinbotham, M. K. Jones, B. Moffit, K. Wang, X. Jiang, and W. Chen
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Scattering, Hadron, chemistry.chemical_element, Parton, Horizontal plane, Polarization (waves), Helicity, Nuclear physics, chemistry, Cathode ray, High Energy Physics::Experiment, Nuclear Experiment, Helium
Abstract: We report the measurement of beam-target double-spin asymmetries ALT in the inclusive production of identified hadrons, e +³He↑ → h + X, using a longitudinally polarized 5.9 GeV electron beam and a transversely polarized ³He target. Hadrons (π±, K± and proton) were detected at 16° with an average momentum h>=2.35 GeV/c and a transverse momentum (pT) coverage from 0.60 to 0.68 GeV/c. Asymmetries from the ³He target were observed to be non-zero for π± production when the target was polarized transversely in the horizontal plane. The π⁺ and π⁻ asymmetries have opposite signs, analogous to the behavior of ALT in semi-inclusive deep-inelastic scattering.
Published: 2015
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16. Development of high-performance alkali-hybrid polarizedHe3targets for electron scattering

Author: T. Averett, William A. Tobias, P. A. M. Dolph, Jaideep Singh, Karen Mooney, Vladimir Nelyubin, Yunxiao Wang, Yuan Zheng, Gordon D. Cates, and Aiden Kelleher
Subjects: Nuclear physics, Optical pumping, Physics, Nuclear and High Energy Physics, Spin polarization, Development (differential geometry), Atmospheric temperature range, Alkali metal, Polarization (waves), Electron scattering, Characterization (materials science), Computational physics
Abstract: We present the development of high-performance polarized ³He targets for use in electron scattering experiments that utilize the technique of alkali-hybrid spin-exchange optical pumping. We include data obtained during the characterization of 24 separate target cells, each of which was constructed while preparing for one of four experiments at Jefferson Laboratory in Newport News, Virginia. The results presented here document dramatic improvement in the performance of polarized ³He targets, as well as the target properties and operating parameters that made those improvements possible. Included in our measurements were determinations of the so-called X-factors that quantify a temperature-dependent and as-yet poorly understood spin-relaxation mechanism that limits the maximum achievable ³He polarization to well under 100%. The presence of this spin-relaxation mechanism was clearly evident in our data. We also present results from a simulation of the alkali-hydrid spin-exchange optical pumping process that was developed to provide guidance in the design of these targets. Good agreement with actual performance was obtained by including details such as off-resonant optical pumping. Now benchmarked against experimental data, the simulation is useful for the design of future targets. Included in our results is a measurement of the K- ³He spin-exchange rate coefficient $$k^\mathrm{K}_\mathrm{se} = \left ( 7.46 \pm 0.62 \right )\!\times\!10^{-20}\ \mathrm{cm^3/s}$$ over the temperature range 503 K to 563 K.
Published: 2015
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17. Constraints on the nucleon strange form factors at Q2∼0.1 GeV2

Author: V. Sulkosky, J. LeRose, M. Mazouz, L. J. Kaufman, R. I. Pomatsalyuk, S. K. Nanda, Yujie Qiang, J. P. Chen, P. Decowski, P. Monaghan, J. Cahoon, B. Craver, F. Garibaldi, G. M. Urciuoli, D. J. Margaziotis, T. Averett, H. Benaoum, H. F. Ibrahim, Bogdan Wojtsekhowski, V. Gorbenko, B. Reitz, J. Roche, Kent Paschke, Seonho Choi, E. Chudakov, William A. Tobias, Peter S. LaViolette, E. Burtin, A. V. Glamazdin, Ronald Gilman, R. Subedi, A. Kolarkar, R. Suleiman, D. Lambert, K. Fuoti, Douglas Higinbotham, D. S. Armstrong, R. Snyder, R. J. Feuerbach, K. McCormick, A. Kelleher, C. W. de Jager, K. Wang, Antonin Vacheret, X. Zheng, K. A. Aniol, Bryan J. Moffit, C. Ferdi, D. Neyret, Jaideep Singh, M. Poelker, F. Cusanno, Nilanga Liyanage, Richard Wilson, Z. E. Meziani, D. G. Meekins, R. Holmes, S. Frullani, S. Kowalski, D. Lhuillier, E. Voutier, J. M. Finn, M. Stutzman, Paul Souder, D. Deepa, G. D. Cates, A. Saha, J. Hansknecht, T. Holmstrom, C. Muñoz-Camacho, R. Michaels, V. Nelyubin, X. Jiang, T. B. Humensky, Y. C. Chao, J. Grames, C. C. Chang, K. S. Kumar, and P.Y. Bertin
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Magnetic moment, Neutral current, 010308 nuclear & particles physics, Scattering, media_common.quotation_subject, Form factor (quantum field theory), 01 natural sciences, Asymmetry, Nuclear physics, 0103 physical sciences, Neutron, 010306 general physics, Nucleon, Beam energy, media_common
Abstract: We report the most precise measurement to date of a parity-violating asymmetry in elastic electron–proton scattering. The measurement was carried out with a beam energy of 3.03 GeV and a scattering angle 〈 θ lab 〉 = 6.0 ○ , with the result A PV = ( − 1.14 ± 0.24 ( stat ) ± 0.06 ( syst ) ) × 10 −6 . From this we extract, at Q 2 = 0.099 GeV 2 , the strange form factor combination G E s + 0.080 G M s = 0.030 ± 0.025 ( stat ) ± 0.006 ( syst ) ± 0.012 ( FF ) where the first two errors are experimental and the last error is due to the uncertainty in the neutron electromagnetic form factor. This result significantly improves current knowledge of G E s and G M s at Q 2 ∼ 0.1 GeV 2 . A consistent picture emerges when several measurements at about the same Q 2 value are combined: G E s is consistent with zero while positive values are favored for G M s , though G E s = G M s = 0 is compatible with the data at 95% C.L.
Published: 2006
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18. Higher twists and color polarizabilities in the neutron

Author: X. Jiang, J. P. Chen, Nilanga Liyanage, Z. E. Meziani, T. Averett, Seonho Choi, Ronald Gilman, E. W. Hughes, K. Kramer, G. Gates, Karl Slifer, C. W. de Jager, F. Garibaldi, A. Deur, Wally Melnitchouk, Wolfgang Korsch, J. C. Yang, and Haiyan Gao
Subjects: Nuclear physics, Quark, Physics, Nuclear and High Energy Physics, Particle physics, Polarizability, Hadron, Structure function, Moment (physics), Duality (optimization), Resonance, Neutron, Nuclear Experiment
Abstract: Color polarizabilities of the neutron are extracted from data on the lowest moment of the spin-dependent g 1 structure function. New data in the resonance region from Jefferson Lab at Q 2 ≲ 1 GeV 2 , in combination with world data at higher Q 2 , allow a systematic determination of the 1 / Q 2 corrections, and provide the first constraints on 1 / Q 4 corrections. The results suggest that higher-twist effects in the neutron are small, and that quark–hadron duality may be approximately valid, even down to Q 2 ∼ 1 GeV 2 .
Published: 2005
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19. The Qweak experimental apparatus

Author: J. R. Hoskins, R. S. Beminiwattha, J. Birchall, J. Diefenbach, Juliette Mammei, J. Balewski, Erik Urban, J. F. Dowd, K. Johnston, G. Clark, P.W. Rose, B. Sawatzky, P. Solvignon, M. Kargiantoulakis, M. Elaasar, J. Mei, S. Sobczynski, A. Micherdzinska, A. Kubera, M. K. Jones, R.B. Zielinski, Mitchell D. Anderson, T. Averett, R. Suleiman, V. M. Gray, E. Henderson, R.D. Carlini, S. A. Wood, Neven Simicevic, J. D. Bowman, A. Mkrtchyan, Amber McCreary, Darko Androić, V. Tvaskis, E. Bonnell, N. Morgan, R. Mahurin, Kent Paschke, R. Averill, J. Beaufait, J. Roche, S. Zhamkochyan, D. J. Mack, C. A. Davis, Fatiha Benmokhtar, S. A. Page, D.C. Dean, J. M. Finn, P. Medeiros, Jean-Francois Rajotte, R. Subedi, G. D. Cates, S. Wells, F. Guo, S. MacEwan, P. Wang, J. A. Dunne, Jongmin Lee, T. Seva, E. Korkmaz, S. K. Phillips, D. C. Jones, P. Brindza, Amrendra Narayan, M. Poelker, J. Pan, J. Leacock, A. R. Lee, V. Tadevosyan, D. Gaskell, Y. Liang, R. Michaels, M. M. Dalton, D.J. Harrison, A.K. Opper, J. Grames, M. McDonald, S. Kowalski, J.C. Cornejo, W. S. Duvall, W. D. Ramsay, A. Asaturyan, J. Leckey, K. Grimm, J. W. Martin, B. Stokes, P. M. King, Michael Gericke, K. E. Mesick, H. Mkrtchyan, E. Ihloff, J. A. Magee, Nadeem A. Khan, L. Lee, J. Kelsey, Trent Allison, Jay Benesch, S. Yang, D. T. Spayde, B. Waidyawansa, D.B. Brown, S. Covrig Dusa, Dipangkar Dutta, W. R. Falk, R. Silwal, A. Subedi, Vladimir Nelyubin, J. Bessuille, D. G. Meekins, R. T. Jones, J. Hansknecht, Nuruzzaman, W. T. H. van Oers, K.D. Finelli, Michael Pitt, J.R. Echols, D. S. Armstrong, G. R. Smith, Douglas Storey, M. J. McHugh, M. H. Shabestari, J. Musson, K. A. Dow, L. Z. Ndukum, Wouter Deconinck, W.R. Roberts, William A. Tobias, and B. S. Cavness
Subjects: Physics, Nuclear and High Energy Physics, business.industry, Compton scattering, Collimator, Electron, Helicity, law.invention, Nuclear physics, Optics, Beamline, law, Scintillation counter, Cathode ray, Physics::Accelerator Physics, Parity violation, Electron scattering, Liquid hydrogen target, business, Instrumentation, Cherenkov radiation
Abstract: The Jefferson Lab Q weak experiment determined the weak charge of the proton by measuring the parity-violating elastic scattering asymmetry of longitudinally polarized electrons from an unpolarized liquid hydrogen target at small momentum transfer. A custom apparatus was designed for this experiment to meet the technical challenges presented by the smallest and most precise e → p asymmetry ever measured. Technical milestones were achieved at Jefferson Lab in target power, beam current, beam helicity reversal rate, polarimetry, detected rates, and control of helicity-correlated beam properties. The experiment employed 180 μA of 89% longitudinally polarized electrons whose helicity was reversed 960 times per second. The electrons were accelerated to 1.16 GeV and directed to a beamline with extensive instrumentation to measure helicity-correlated beam properties that can induce false asymmetries. Moller and Compton polarimetry were used to measure the electron beam polarization to better than 1%. The electron beam was incident on a 34.4 cm liquid hydrogen target. After passing through a triple collimator system, scattered electrons between 5.8° and 11.6° were bent in the toroidal magnetic field of a resistive copper-coil magnet. The electrons inside this acceptance were focused onto eight fused silica Cherenkov detectors arrayed symmetrically around the beam axis. A total scattered electron rate of about 7 GHz was incident on the detector array. The detectors were read out in integrating mode by custom-built low-noise pre-amplifiers and 18-bit sampling ADC modules. The momentum transfer Q 2 =0.025 GeV 2 was determined using dedicated low-current ( ~ 100 pA ) measurements with a set of drift chambers before (and a set of drift chambers and trigger scintillation counters after) the toroidal magnet.
Published: 2015

20. Measurement of 'pretzelosity' asymmetry of charged pion production in semi-inclusive deep inelastic scattering on a polarizedHe3target

Author: Jen-Chieh Peng, M. Osipenko, L. Yuan, K. Chirapatpimol, J. P. Chen, Y. X. Ye, Franco Garibaldi, Simon Širca, Y. Zhang, M. Huang, W. Kim, R. A. Lindgren, J. J. LeRose, J. Huang, G. M. Urciuoli, A. Kolarkar, A. Deur, X. Jiang, A. Saha, I. Vilardi, H. Ding, Salvatore Frullani, D. J. Margaziotis, M. M. Dalton, M. H. Shabestari, J. C. Cornejo, S. Riordan, R. Michaels, Xiaofeng Zhu, Douglas Higinbotham, M. K. Jones, C. Muñoz Camacho, B. Sawatzky, L. G. Tang, B. Zhao, X. Li, X. Zhan, X. Yan, M. Posik, X. Deng, Y. Li, Mauro Iodice, Abdurahim Rakhman, P. C. Bradshaw, William Bertozzi, T. Averett, S. Golge, D. McNulty, A. Camsonne, H. J. Lu, T. Holmstrom, David Hamilton, Pete Markowitz, H. Yao, Diana Parno, L. Guo, K. Wang, X. Zong, Chunhui Chen, Vincent Sulkosky, E. Long, S. Marrone, W. Chen, Z. E. Meziani, R. De Leo, Bogdan Wojtsekhowski, G. D. Cates, Yong Zhang, S. S. Stepanyan, A. Kelleher, B. Moffit, Vladimir Nelyubin, F. Cusanno, Nilanga Liyanage, Amrendra Narayan, Joseph M. Katich, P. Bosted, A. J. R. Puckett, Z. Ye, B. E. Norum, Mustafa Canan, Kalyan Allada, D. Gaskell, A. Shahinyan, Wolfgang Korsch, Fatiha Benmokhtar, E. Cisbani, Ronald Gilman, P. A. M. Dolph, Ronald Ransome, Xin Qian, L. El Fassi, Young Do Oh, C. Dutta, William A. Tobias, Yingxiao Wang, G. Jin, X. Zheng, S. K. Phillips, Shalev Gilad, C. W. de Jager, K. A. Aniol, H. F. Ibrahim, S. K. Nanda, Yujie Qiang, Dipangkar Dutta, Wouter Deconinck, R. Subedi, E. Chudakov, O. Glamazdin, Olfred Hansen, J. R. M. Annand, L. Y. Zhu, Haiyan Gao, and E. Schulte
Subjects: Quark, Physics, Nuclear and High Energy Physics, Particle physics, Scattering, media_common.quotation_subject, Deep inelastic scattering, Asymmetry, Nuclear physics, Pion, Distribution function, Neutron, Nuclear Experiment, Nucleon, media_common
Abstract: An experiment to measure single-spin asymmetries of semi-inclusive production of charged pions in deep-inelastic scattering on a transversely polarized $^{3}\mathrm{He}$ target was performed at Jefferson Laboratory in the kinematic region of $0.16lxl0.35$ and $1.4l{Q}^{2}l2.7$ ${\mathrm{GeV}}^{2}$. Pretzelosity asymmetries on $^{3}\mathrm{He}$, which are expressed as the convolution of the ${h}_{1T}^{\ensuremath{\perp}}$ transverse-momentum-dependent distribution functions and the Collins fragmentation functions in the leading order, were measured for the first time. Under the effective polarization approximation, we extracted the corresponding neutron asymmetries from the measured $^{3}\mathrm{He}$ asymmetries and cross-section ratios between the proton and $^{3}\mathrm{He}$. Our results show that both ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ on $^{3}\mathrm{He}$ and on neutron pretzelosity asymmetries are consistent with zero within experimental uncertainties.
Published: 2014
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21. Measurements of the Q2-dependence of the proton and neutron spin structure functions g1p and g1n

Author: P.L Anthony, R.G Arnold, T Averett, H.R Band, M.C Berisso, H Borel, P.E Bosted, S.L Bültmann, M Buenerd, T Chupp, S Churchwell, G.R Court, D Crabb, D Day, P Decowski, P DePietro, R Erbacher, R Erickson, A Feltham, H Fonvieille, E Frlez, R Gearhart, V Ghazikhanian, J Gomez, K.A Griffioen, C Harris, M.A Houlden, E.W Hughes, C.E Hyde-Wright, G Igo, S Incerti, J Jensen, J.R Johnson, P.M King, Yu.G Kolomensky, S.E Kuhn, R Lindgren, R.M Lombard-Nelsen, J Marroncle, J McCarthy, P McKee, W Meyer, G.S Mitchell, J Mitchell, M Olson, S Penttila, G.A Peterson, G.G Petratos, R Pitthan, D Pocanic, R Prepost, C Prescott, L.M Qin, B.A Raue, D Reyna, L.S Rochester, S Rock, O.A Rondon-Aramayo, F Sabatie, I Sick, T Smith, L Sorrell, F Staley, S.St Lorant, L.M Stuart, Z Szalata, Y Terrien, A Tobias, L Todor, T Toole, S Trentalange, D Walz, R.C Welsh, F.R Wesselmann, T.R Wright, C.C Young, M Zeier, H Zhu, and B Zihlmann
Subjects: Nuclear physics, Quantum chromodynamics, Physics, High Energy Physics - Phenomenology, Nuclear and High Energy Physics, Particle physics, Deuterium, Proton, Scattering, Neutron, Electron, Sum rule in quantum mechanics, Spin structure
Abstract: The structure functions g1p and g1n have been measured over the range 0.014 < x < 0.9 and 1 < Q2 < 40 GeV2 using deep-inelastic scattering of 48 GeV longitudinally polarized electrons from polarized protons and deuterons. We find that the Q2 dependence of g1p (g1n) at fixed x is very similar to that of the spin-averaged structure function F1p (F1n). From a NLO QCD fit to all available data we find $\Gamma_1^p - \Gamma_1^n =0.176 \pm 0.003 \pm 0.007$ at Q2=5 GeV2, in agreement with the Bjorken sum rule prediction of 0.182 \pm 0.005., Comment: 17 pages, 3 figures. Submitted to Physics Letters B
Published: 2000
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22. An energy feedback system for the MIT/Bates linear accelerator

Author: D. Barkhuff, G. W. Dodson, C. Tschalaer, B. Mueller, E. J. Beise, D. T. Spayde, S. Kowalski, S. P. Wells, A. Zolfaghari, T. Averett, Douglas H Beck, R. D. McKeown, D. Cheever, and Michael Pitt
Subjects: Physics, Nuclear and High Energy Physics, business.industry, Electrical engineering, FOS: Physical sciences, BATES, Line (electrical engineering), Linear particle accelerator, Energy feedback, Nuclear Experiment (nucl-ex), business, Nuclear Experiment, Instrumentation, Energy (signal processing), Order of magnitude, Voltage
Abstract: We report the development and implementation of an energy feedback system for the MIT/Bates Linear Accelerator Center. General requirements of the system are described, as are the specific requirements, features, and components of the system unique to its implementation at the Bates Laboratory. We demonstrate that with the system in operation, energy fluctuations correlated with the 60 Hz line voltage and with drifts of thermal origin are reduced by an order of magnitude.
Published: 2000
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23. Electron beam position stabilization with a piezo-electric optical correction system

Author: Michael Pitt, T. Averett, C. E. Jones, and R. D. McKeown
Subjects: Physics, Nuclear and High Energy Physics, business.industry, Parity (physics), Electron, Laser, Signal, Helicity, Linear particle accelerator, law.invention, Optics, law, Position (vector), Cathode ray, Atomic physics, business, Instrumentation
Abstract: A piezo-electrically controlled optical correction system was successfully used to reduce the helicity-correlated pulse-to-pulse position differences of a laser spot to better than ±100 nm at a pulse rate of 600 Hz. Using a simple feedback algorithm, average position differences of Δ x =−3.5±4.2 nm and Δ y =2.6±6.6 nm were obtained over a 6 h period. This optical correction system was successfully used in the polarized electron source at the Bates Linear Accelerator Center to stabilize the position of the electron beam during the recent SAMPLE experiment. Because this experiment measures a parity violating signal at the 10−6 level, it is sensitive to systematic effects which are correlated with the helicity of the incident electrons. One potentially large systematic effect is the helicity-correlated motion of the incident electron beam. By using this optical correction system, electron beam position differences at the location of the experiment were routinely kept well below ±100 nm, with averages over the entire two month run of Δ x =6.4±2.3 nm and Δ y =−3.5±2.0 nm.
Published: 1999
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24. Measurement of the deuteron spin structure function g1d(x) for 1 (GeV/c)2<Q2<40 (GeV/c)2

Author: R. Erbacher, V. Ghazikhanian, G. G. Petratos, O. Rondon-Aramayo, B. A. Raue, H. Borel, Stephen M. Rock, K. A. Griffioen, H. R. Band, T. Averett, E. W. Hughes, Hongbo Zhu, L. S. Rochester, S. Bültmann, F. Sabatié, P.M. King, R. Gearhart, D. Crabb, L. Todor, J. Marroncle, P. McKee, Yu. G. Kolomensky, R. A. Lindgren, T. R. Wright, M. Olson, A. Feltham, Timothy B. Smith, D. Walz, R. G. Arnold, M. Zeier, L. M. Stuart, P. E. Bosted, B. Zihlmann, S. Trentalange, S.St. Lorant, L.M. Qin, John C. Mitchell, J. S. McCarthy, F.R. Wesselmann, G. A. Peterson, C. Harris, Ingo Sick, R. Prepost, C. Y. Prescott, D. Reyna, Gregory S. Mitchell, G. Igo, Donal Day, P.L. Anthony, H. Fonvieille, Emil Frlez, M.C. Berisso, R. M. Lombard-Nelsen, W. Meyer, J. Gomez, S. Churchwell, Ch. Hyde-Wright, Y. Terrien, J. R. Johnson, S. I. Penttilä, L. Sorrell, J. Jensen, R. Pitthan, F. Staley, M. A. Houlden, C. C. Young, P. Decowski, R. Erickson, Dinko Pocanic, Robert C. Welsh, S. E. Kuhn, P. DePietro, Z. M. Szalata, Sebastien Incerti, G.R. Court, A. Tobias, T. Toole, Timothy Chupp, and M.J. Buenerd
Subjects: Quark, Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Deuterium, Nuclear Theory, Electron, Spin structure, Nuclear Experiment, Polarization (waves), Deep inelastic scattering, High Energy Physics - Experiment
Abstract: New measurements are reported on the deuteron spin structure function g_1^d. These results were obtained from deep inelastic scattering of 48.3 GeV electrons on polarized deuterons in the kinematic range 0.01 < x < 0.9 and 1 < Q^2 < 40 (GeV/c)^2. These are the first high dose electron scattering data obtained using lithium deuteride (6Li2H) as the target material. Extrapolations of the data were performed to obtain moments of g_1^d, including Gamma_1^d, and the net quark polarization Delta Sigma., Comment: 5 pages, 2 figures
Published: 1999
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25. Inclusive hadron photoproduction from longitudinally polarized protons and deuterons

Author: P.L. Anthony, R.G. Arnold, T. Averett, H.R. Band, M.C. Berisso, H. Borel, P.E. Bosted, S.L. Bültmann, M. Buenerd, T. Chupp, S. Churchwell, G.R. Court, D. Crabb, D. Day, P. Decowski, P. DePietro, R. Erbacher, R. Erickson, A. Feltham, H. Fonvieille, E. Frlez, R. Gearhart, V. Ghazikhanian, J. Gomez, K.A. Griffioen, C. Harris, M.A. Houlden, E.W. Hughes, C.E. Hyde-Wright, G. Igo, S. Incerti, J. Jensen, J.R. Johnson, P.M. King, Yu.G. Kolomensky, S.E. Kuhn, R. Lindgren, R.M. Lombard-Nelsen, J. Marroncle, J. McCarthy, P. McKee, W. Meyer, G.S. Mitchell, J. Mitchell, M. Olson, S. Penttila, G.A. Peterson, G.G. Petratos, R. Pitthan, D. Pocanic, R. Prepost, C. Prescott, L.M. Qin, B.A. Raue, D. Reyna, L.S. Rochester, S. Rock, O.A. Rondon-Aramayo, F. Sabatie, I. Sick, T. Smith, L. Sorrell, F. Staley, S.St. Lorant, L.M. Stuart, Z. Szalata, Y. Terrien, A. Tobias, L. Todor, T. Toole, S. Trentalange, D. Walz, R.C. Welsh, F.R. Wesselmann, T.R. Wright, C.C. Young, M. Zeier, H. Zhu, and B. Zihlmann
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Range (particle radiation), Photon, Proton, media_common.quotation_subject, Nuclear Theory, Hadron, Bremsstrahlung, FOS: Physical sciences, Asymmetry, Momentum, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Pion, High Energy Physics::Experiment, Nuclear Experiment, media_common
Abstract: We report measurements of the asymmetry A_parallel for inclusive hadron production on longitudinally polarized proton and deuteron targets by circularly polarized photons. The photons were produced via internal and external bremsstrahlung from an electron beam of 48.35 GeV. Asymmetries for both positive and negative signed hadrons, and a subset of identified pions, were measured in the momentum range 10, Comment: 8 pages, 4 figures. Submitted to Physics Letters B
Published: 1999
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26. Measurements of R=σL/σT for 0.03<x<0.1 and fit to world data

Author: P. Raines, Ingo Sick, S.St. Lorant, D. Kawall, H. Borel, H. Tang, C. Y. Prescott, J. M. Bauer, H. R. Band, R. G. Arnold, F. S. Dietrich, L. M. Stuart, T. Maruyama, Ch. Hyde-Wright, D. Walz, J. L. White, J. S. McCarthy, P. E. Bosted, G. Court, T. Averett, Vincent Breton, P. Grenier, B. Raue, Kevin P. Coulter, S. Hoibraten, Pascal Steiner, R. Erbacher, F. Staley, D. Reyna, O. Rondon, P.L. Anthony, K. A. Griffioen, A. Feltham, E. W. Hughes, D. Crabb, J. Button-Shafer, R. Prepost, S. E. Rock, Timothy Chupp, A. Rijllart, J. Gomez, Timothy B. Smith, Y. Terrien, J. A. Dunne, L. C. Smith, K. Witte, T. L. Usher, W. Meyer, C. C. Young, J. Fellbaum, J. R. Johnson, D. Zimmermann, Avraham Klein, J. Morgenstern, M. Kuriki, Y. Roblin, Donal Day, Z. E. Meziani, F. Suekane, J. P. Chen, H. Dutz, R. C. Minehart, B. Zihlmann, Emil Frlez, B. Youngman, Koji Abe, R. Antonov, R. M. Lombard-Nelsen, H. Fonvieille, L. S. Rochester, R. A. Lindgren, G. G. Petratos, R. Gearhart, J. Marroncle, F.R. Wesselmann, John C. Mitchell, H. Yuta, G. H. Zapalac, R. Pitthan, J. Clendenin, T. J. Liu, Dinko Pocanic, S. E. Kuhn, Z. M. Szalata, T. Akagi, M. Spengos, X.K. Maruyama, D. Garvey, C. Comptour, and M. Daoudi
Subjects: Physics, Nuclear and High Energy Physics, Cross section.transverse, 010308 nuclear & particles physics, Scattering, chemistry.chemical_element, Electron, 01 natural sciences, Nuclear physics, Cross section (physics), chemistry, 0103 physical sciences, 010306 general physics, Carbon
Abstract: Measurements were made at SLAC of the cross section for scattering 29 GeV electrons from carbon at a laboratory angle of 4.5°, corresponding to 0.03
Published: 1999
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27. Spin-dependent cross sections from the three-body photodisintegration ofHe3at incident energies of 12.8 and 14.7 MeV

Author: R. Skibiński, Jacek Golak, G. Laskaris, Brent Perdue, M. W. Ahmed, H. R. Weller, Dipangkar Dutta, Ying Wu, W. Zheng, Y. Zhang, Haiyan Gao, Q. J. Ye, L. S. Myers, J. R. Tompkins, A. Deltuva, M. Huang, Xin Qian, Henryk Witała, A. C. Fonseca, P. U. Sauer, Hugon J Karwowski, Jonathan Mueller, Chao Peng, Q. Ye, B. Lalremruata, S. Stave, and T. Averett
Subjects: Physics, Optical pumping, Nuclear and High Energy Physics, Photodisintegration, Coulomb, Photon beam, Atomic physics, Spin (physics), Alkali metal
Abstract: The first measurement of the three-body photodisintegration of polarized $^{3}\mathrm{He}$ using a circularly polarized photon beam has been performed at incident energies of 12.8 and 14.7 MeV. This measurement was carried out at the high-intensity $\ensuremath{\gamma}$-ray source located at Triangle Universities Nuclear Laboratory. A high-pressure $^{3}\mathrm{He}$ target, polarized via spin exchange optical pumping with alkali metals, was used in the experiment. The spin-dependent double- and single-differential cross sections from $\stackrel{P\vec}{{}^{3}\text{He}}(\stackrel{P\vec}{\ensuremath{\gamma}},n)pp$ for laboratory angles varying from ${30}^{\ensuremath{\circ}}$ to ${165}^{\ensuremath{\circ}}$ are presented and compared with state-of-the-art three-body calculations. The data reveal the importance of including the Coulomb interaction between protons in the three-body calculations.
Published: 2014
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28. Measurement of the neutron spin structure function g and asymmetry A

Author: K. Abe, T. Akagi, B.D. Anderson, P.L. Anthony, R.G. Arnold, T. Averett, H.R. Band, C.M. Berisso, P. Bogorad, H. Borel, P.E. Bosted, V. Breton, M.J. Buenerd, G.D. Cates, T.E. Chupp, S. Churchwell, K.P. Coulter, M. Daoudi, P. Decowski, R. Erickson, J.N. Fellbaum, H. Fonvieille, R. Gearhart, V. Ghazikhanian, K.A. Griffioen, R.S. Hicks, R. Holmes, E.W. Hughes, G. Igo, S. Incerti, J.R. Johnson, W. Kahl, M. Khayat, Yu.G. Kolomensky, S.E. Kuhn, K. Kumar, M. Kuriki, R. Lombard-Nelsen, D.M. Manley, J. Marroncle, T. Maruyama, T. Marvin, W. Meyer, Z.-E. Meziani, D. Miller, G. Mitchell, M. Olson, G.A. Peterson, G.G. Petratos, R. Pitthan, R. Prepost, P. Raines, B.A. Raue, D. Reyna, L.S. Rochester, S.E. Rock, M.V. Romalis, F. Sabatie, G. Shapiro, J. Shaw, T.B. Smith, L. Sorrell, P.A. Souder, F. Staley, S.St. Lorant, L.M. Stuart, F. Suckane, Z.M. Szalata, Y. Terrien, A.K. Thompson, T. Toole, X. Wang, J.W. Watson, R.C. Welsh, F.R. Wesselmann, T. Wright, C.C. Young, B. Youngman, H. Yuta, W.-M. Zhang, and P. Zyla
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Scattering, media_common.quotation_subject, Structure function, Electron, Function (mathematics), Spin structure, 01 natural sciences, 7. Clean energy, Asymmetry, 0103 physical sciences, Neutron, Matrix element, 010306 general physics, media_common
Abstract: We have measured the neutron structure function g$_{2}^{n}$ and the virtual photon-nucleon asymmetry A$_{2}^{n}$ over the kinematic range $0.014\leq x \leq 0.7$ and $1.0 \leq Q^{2} \leq 17.0$ by scattering 48.3 GeV longitudinally polarized electrons from polarized $^{3}$He. Results for A$_{2}^{n}$ are significantly smaller than the $\sqrt{R}$ positivity limit over most of the measured range and data for g$_2^{n}$ are generally consistent with the twist-2 Wandzura-Wilczek prediction. Using our measured g$_{2}^{n}$ we obtain results for the twist-3 reduced matrix element $d_{2}^{n}$, and the integral $\int$g$_{2}^{n}(x)dx$ in the range $0.014\leq x \leq 1.0$. Data from this experiment are combined with existing data for g$_{2}^{n}$ to obtain an average for $d_{2}^{n}$ and the integral $\int$g$_{2}^{n}(x)dx$.
Published: 1997
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29. Single Spin Asymmetries of Inclusive Hadrons Produced in Electron Scattering from a Transversely Polarized $^3$He Target

Author: B. Sawatzky, X. Li, M. Posik, A. Camsonne, Xiaofeng Zhu, Mauro Iodice, Nilanga Liyanage, Vincent Sulkosky, Yingxiao Wang, T. Averett, J. P. Chen, Bogdan Wojtsekhowski, X. Zong, J. Huang, G. M. Urciuoli, Ronald Gilman, J. C. Cornejo, X. Yan, A. J. R. Puckett, Shalev Gilad, C. W. de Jager, R. A. Lindgren, J. J. LeRose, E. Cisbani, K. A. Aniol, W. Kim, M. H. Shabestari, Fatiha Benmokhtar, L. G. Tang, I. Vilardi, B. Moffit, A. Tobias, Wouter Deconinck, H. Ding, R. Michaels, Franco Garibaldi, Salvatore Frullani, Simon Širca, William Bertozzi, R. Subedi, F. Cusanno, G. D. Cates, A. Kolarkar, X. Deng, Amrendra Narayan, H. J. Lu, David Hamilton, Pete Markowitz, H. Yao, Joseph M. Katich, D. Gaskell, A. Deur, Haiyan Gao, C. Dutta, Y. Li, P. A. M. Dolph, R. De Leo, T. Holmstrom, D. McNulty, Arijit Saha, G. Jin, X. Zhan, Douglas Higinbotham, M. K. Jones, X. Zheng, O. Glamazdin, Olfred Hansen, J. R. M. Annand, S. Marrone, Chunhui Chen, Jen-Chieh Peng, S. K. Nanda, L. Guo, A. Shahinyan, M. Osipenko, Yujie Qiang, W. Chen, E. Long, L. Y. Zhu, K. Wang, Z. Ye, B. E. Norum, Y. Zhao, L. Yuan, Y. X. Ye, K. Chirapatpimol, Ronald Ransome, Y. Zhang, Diana Parno, Xin Qian, P. C. Bradshaw, A. Kelleher, E. Schulte, P. Bosted, M. Huang, S. Golge, X. Jiang, L. El Fassi, Z. E. Meziani, Wolfgang Korsch, D. J. Margaziotis, Young Do Oh, S. K. Phillips, C. Muñoz Camacho, B. Zhao, H. F. Ibrahim, Dipangkar Dutta, E. Chudakov, S. S. Stepanyan, Mustafa Canan, Kalyan Allada, Abdurahim Rakhman, Yong Zhang, Vladimir Nelyubin, M. M. Dalton, and S. Riordan
Subjects: Physics, Nuclear and High Energy Physics, Range (particle radiation), Proton, media_common.quotation_subject, Nuclear Theory, Hadron, High Energy Physics::Phenomenology, FOS: Physical sciences, Asymmetry, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Pion, Neutron, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment, Electron scattering, Spin-½, media_common
Abstract: We report the first measurement of target single-spin asymmetries (A$_N$) in the inclusive hadron production reaction, $e~$+$~^3\text{He}^{\uparrow}\rightarrow h+X$, using a transversely polarized $^3$He target. The experiment was conducted at Jefferson Lab in Hall A using a 5.9-GeV electron beam. Three types of hadrons ($\pi^{\pm}$, $\text{K}^{\pm}$ and proton) were detected in the transverse hadron momentum range 0.54 $, Comment: Updated version, submitted to Phys. Rev. C
Published: 2013
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30. Measurements of the Q2-dependence of the proton and deuteron spin structure functions g1 and g1

Author: A. Rijllart, J. Marroncle, Z. M. Szalata, J. Clendenin, T. Akagi, P. Raines, H. Dutz, T. J. Liu, Dinko Pocanic, H. R. Band, M. Kuriki, J. P. Chen, John C. Mitchell, S. E. Kuhn, B. Youngman, R. Prepost, S.St. Lorant, D. Walz, G. Court, Ingo Sick, Timothy B. Smith, J. Gomez, X.K. Maruyama, D. Kawall, K. Witte, L. M. Stuart, T. Maruyama, P. E. Bosted, P.L. Anthony, J. Fellbaum, C. Comptour, M. Daoudi, C. E. Hyde-Wright, R. Pitthan, D. Garvey, C. Y. Prescott, W. Meyer, Avraham Klein, R. A. Lindgren, G. G. Petratos, M. Spengos, F. Staley, L.S. Rochester, C. C. Young, T. L. Usher, B. Raue, S. Hoibraten, R. C. Minehart, D. Zimmermann, Pascal Steiner, H. Yuta, P. Grenier, K. A. Griffioen, Timothy Chupp, L. C. Smith, F. Suekane, J. Morgenstern, J. R. Johnson, G. H. Zapalac, Donal Day, Y. Roblin, D. G. Crabb, H. Tang, J. Button-Shafer, Koji Abe, J. A. Dunne, H. Fonvieille, H. Borel, J. S. McCarthy, F. S. Dietrich, T. Averett, R. G. Arnold, R. Erbacher, Z. E. Meziani, D. Reyna, R. A. Gearhart, A. Feltham, E. W. Hughes, J. L. White, J. M. Bauer, Vincent Breton, Kevin P. Coulter, O. Rondon, S. E. Rock, Y. Terrien, B. Zihlmann, Emil Frlez, R. Antonov, and R. M. Lombard-Nelsen
Subjects: Nuclear physics, Physics, High Energy Physics - Experiment (hep-ex), Nuclear and High Energy Physics, Deuterium, Proton, FOS: Physical sciences, Spin structure, High Energy Physics - Experiment
Abstract: The ratio g1/F1 has been measured over the range 0.031 (GeV/c)2. A trend is observed for g1/F1 to decrease at lower Q2. Fits to world data with and without a possible Q2-dependence in g1/F1 are in agreement with the Bjorken sum rule, but Delta_q is substantially less than the quark-parton model expectation., Comment: 16 pages, format is postscript file, gzip-ed, uuencode-ed
Published: 1995
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31. Final analysis of proton form factor ratio data atQ2=4.0, 4.8, and 5.6 GeV2

Author: C. Cavata, T. Averett, J. R. Calarco, R. Endres, S. Kozlov, J. P. Chen, Kevin Fissum, C. C. Chang, I. Sitnik, Shalev Gilad, C. W. de Jager, A. V. Glamazdin, Z. Chai, K. A. Aniol, K. Wijesooriya, G. M. Urciuoli, E. Tomasi-Gustafsson, D. J. Margaziotis, X. Jiang, Douglas Higinbotham, M. K. Jones, N. M. Piskunov, Bogdan Wojtsekhowski, Fatiha Benmokhtar, R. Michaels, T. Chang, Charles Glashausser, Stephanie Escoffier, C. F. Perdrisat, L. Bimbot, C. Salgado, Mauro Iodice, L. Todor, R. A. Lindgren, J. J. LeRose, G. J. Lolos, M. B. Epstein, H. Voskanyan, K. Kramer, F. Marie, V. A. Punjabi, William Bertozzi, Brian Raue, Pete Markowitz, M. Rvachev, M. Khandaker, R. De Leo, D. Neyret, S. Frullani, Olivier Gayou, J. Gomez, Ronald Gilman, S. Strauch, E. Chudakov, J. O. Hansen, G. J. Kumbartzki, H. Fonvieille, B. D. Milbrath, E. J. Brash, K. McCormick, R. Roche, J. Gao, Simon Širca, G. M. Huber, F. Garibaldi, S. K. Nanda, Andrew Puckett, Sonja Dieterich, X. Zheng, D. Lhuillier, Nilanga Liyanage, L. Zhu, L. Pentchev, and Ronald Ransome
Subjects: Quark, Physics, Nuclear physics, Nuclear and High Energy Physics, Angular momentum, 010308 nuclear & particles physics, 0103 physical sciences, Momentum transfer, 010306 general physics, Nucleon, Polarization (waves), 01 natural sciences
Abstract: Precise measurements of the proton electromagnetic form factor ratio R = mu(p)G(E)(p)/G(M)(p) using the polarization transfer method at Jefferson Lab have revolutionized the understanding of nucleon structure by revealing the strong decrease of R with momentum transfer Q(2) for Q(2) greater than or similar to 1 GeV2, in strong disagreement with previous extractions of R from cross-section measurements. In particular, the polarization transfer results have exposed the limits of applicability of the one-photon-exchange approximation and highlighted the role of quark orbital angular momentum in the nucleon structure. The GEp-II experiment in Jefferson Lab's Hall A measured R at four Q(2) values in the range 3.5 GeV2
Published: 2012
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32. Methods for Optical Calibration of the BigBite Hadron Spectrometer

Author: J. P. Chen, J. Huang, Guy Ron, M. H. Shabestari, Yujie Qiang, S. Riordan, S. Širca, J. W. Watson, B. E. Norum, Douglas Higinbotham, J. R. M. Annand, R.W. Chan, Nilanga Liyanage, David Hamilton, Wolfgang Korsch, R. Michaels, J. O. Hansen, K. Chirapatpimol, T. Averett, A. Shahinyan, G. Rosner, Kalyan Allada, B. Sawatzky, X. Jiang, Y.-W. Zhang, Xin Qian, Shalev Gilad, C. W. de Jager, B. Moffit, B. D. Anderson, P. Monaghan, Vladimir Nelyubin, E. Long, R. A. Lindgren, J. J. LeRose, M. Mihovilovič, G. Jin, A. Camsonne, Vincent Sulkosky, E. Piasetzky, R. Shneor, and R. Subedi
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Spectrometer, Hadron, Detector, FOS: Physical sciences, Nuclear physics, Particle type, Optical calibration, Singular value decomposition, Nuclear Experiment (nucl-ex), Nuclear Experiment, Instrumentation
Abstract: The techniques for optical calibration of Jefferson Lab's large-acceptance magnetic hadron spectrometer, BigBite, have been examined. The most consistent and stable results were obtained by using a method based on singular value decomposition. In spite of the complexity of the optics, the particles' positions and momenta at the target have been precisely reconstructed from the coordinates measured in the detectors by means of a single back-tracing matrix. The technique is applicable to any similar magnetic spectrometer and any particle type. For 0.55 GeV/c protons, we have established the vertex resolution of 1.2 cm, angular resolutions of 7 mrad and 16 mrad (in-plane and out-of-plane, respectively), and a relative momentum resolution of 1.6%., Comment: 26 pages, 13 figures
Published: 2012
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33. Pion elastic scattering from polarizedC13in the energy region of theP33resonance

Author: Christopher Morris, M. A. Khandaker, R. Ivie, E. Insko, H. Ward, S. I. Penttilä, G. R. Burleson, S. M. Sterbenz, T. Averett, Gerald W Hoffmann, M. Purcell, D. Dehnhard, Soumya Chakravarti, Barry Ritchie, Y. F. Yen, K. Cranston, Yi Ju Yu, J. R. Comfort, J. A. Faucett, N. Tanaka, A. L. Williams, K. Johnson, Steven J. Greene, J. Görgen, C. F. Moore, J. Tinsley, B. Brinkmöller, J. M. O’Donnell, J. J. Jarmer, M. A. Franey, A. Klein, D. A. Smith, J. A. McGill, B. Berman, G. S. Kyle, H. T. Fortune, Martin L Barlett, and Ricardo Alarcon
Subjects: Physics, Elastic scattering, Nuclear and High Energy Physics, Scattering, Isoscalar, Nuclear Theory, Momentum transfer, Resonance (particle physics), Nuclear physics, Scattering amplitude, Pion, Condensed Matter::Strongly Correlated Electrons, Atomic physics, Born approximation
Abstract: A new development in polarized nuclear-target technology has made it possible to measure analyzing power, Ay, in pion elastic scattering from a polarized target.[1] Such measurements provide us with information on the isoscalar spin-flip strength of the nuclear transition which is very difficult to obtain otherwise. Differential cross sections, σ(Θ), for pion elastic scattering from nuclei with non-zero spin are dominated by the spin-independent (∆S = 0) amplitudes. Contributions from the spin-dependent (∆S = 1) amplitudes are usually negligible because σ(Θ) depends on the sum of the squares of those amplitudes. However, the Ay depend on the interference on the spin-independent and spin-dependent scattering amplitudes and are therefore quite sensitive to the spin-dependent forms.
Published: 1994
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34. Gas dynamics in high-luminosity polarized3He targets using diffusion and convection

Author: T. Averett, P. A. M. Dolph, Karen Mooney, W. A. Tobias, A. Kelleher, V. Nelyubin, Gordon D. Cates, Bogdan Wojtsekhowski, and Jaideep Singh
Subjects: Physics, Convection, Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Luminosity (scattering theory), Scattering, business.industry, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Electron, Resonance (particle physics), High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Optics, Fluid dynamics, Nuclear Experiment (nucl-ex), Diffusion (business), business, Nuclear Experiment, Electron scattering
Abstract: The dynamics of the movement of gas is discussed for two-chambered polarized He-3 target cells of the sort that have been used successfully for many electron scattering experiments. A detailed analysis is presented showing that diffusion is a limiting factor in target performance, particularly as these targets are run at increasingly high luminosities. Measurements are presented on a new prototype polarized He-3 target cell in which the movement of gas is due largely to convection instead of diffusion. NMR tagging techniques have been used to visualize the gas flow, showing velocities along a cylindrically-shaped target of between 5-80 cm/min. The new target design addresses one of the principle obstacles to running polarized He-3 targets at substantially higher luminosities while simultaneously providing new flexibility in target geometry., Comment: First revision: 14 pages, 9 figures, submitted to Phys. Rev. C. We have shortened our discussion of the limitations inherent in various historical He-3 targets, and we have added a discussion exploring the optimal performance that can be expected from a suitably modified target based on diffusion-based mixing. A reference (Jones et. al.) was added. The results we present have not changed
Published: 2011
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35. The G0 Experiment: Apparatus for Parity-Violating Electron Scattering Measurements at Forward and Backward Angles

Author: T. Horn, G. A. Rutledge, R. M. Laszewski, A. Kolarkar, R. Hasty, F. Merchez, E. Liatard, K. Grimm, W. F. Vulcan, J. Yun, H. C. Fenker, R. Carr, R. Suleiman, D. McKee, J. Roche, R. Neveling, K. Johnston, M. Versteegen, Raphael Noel Tieulent, A. Coppens, R. Frascaria, S. A. Wood, T. Averett, P. Pillot, S. Kox, D. Marchand, D. S. Armstrong, K. A. Griffioen, G. R. Smith, C. Yan, G. Guillard, J. Lachniet, E. Voutier, K. W. McFarlane, G. Quéméner, J. Schaub, L. Lee, D. S. Dale, Michael Gericke, A. Hawthorne Allen, Fatiha Benmokhtar, V. Zeps, E. J. Beise, M. Muether, R. Clark, D. J. Mack, Michael Pitt, Jay Benesch, Jonathan W. Martin, W. T. H. van Oers, T. A. Porcelli, J. A. Secrest, W. D. Ramsay, A. A. Cowley, S. Niccolai, H. Guler, C. L. Capuano, S. L. Bailey, J. Arvieux, N. S. Chant, L. Bimbot, P. Kammel, C. Ellis, Bryan J. Moffit, R. Asaturyan, G. Batigne, D. T. Spayde, W. R. Falk, P. M. King, Douglas H Beck, A. Micherdzinska, Takeyasu Ito, John Musson, R. D. McKeown, S. A. Page, S. Wells, J. Kuhn, Y. C. Chao, K. Nakahara, B. Guillon, S. E. Williamson, J. Grames, L. Hannelius, M. Morlet, H. Breuer, J. Van de Wiele, S. K. Phillips, J. Hansknecht, J. S. Real, A. S. Biselli, R. J. Woo, S. Covrig, M. K. Jones, J. Lenoble, S. Ong, H. Mkrtchyan, M. Poelker, D. Gaskell, S.G. Stepanyan, T. A. Forest, C. A. Davis, A. Lung, J. M. Finn, M. Stutzman, S. F. Pate, T. Seva, E. Korkmaz, A. W. Rauf, V. Papavassiliou, P. Brindza, G. A. MacLachlan, V. Tadevosyan, J. Birchall, R. Kazimi, C. Furget, Juliette Mammei, Glen A. Warren, Neven Simicevic, P. G. Roos, D. Nilsson, G. B. Franklin, K. Gustafsson, Wolfgang Korsch, Darko Androić, M. Mihovilovic, Jin Liu, P. Bosted, R. D. Carlini, T. Ries, B. P. Quinn, Mines Nantes (Mines Nantes), Laboratoire SUBATECH Nantes (SUBATECH), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), 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), and G0
Subjects: Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, FOS: Physical sciences, Electron, Mott scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Nuclear physics, magnetic spectrometer, liquid hydrogen target, polarized electron beam, parity-violation, electron scattering, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Instrumentation, Cherenkov radiation, Elastic scattering, Physics, Spectrometer, 010308 nuclear & particles physics, Scattering, Instrumentation and Detectors (physics.ins-det), Small-angle neutron scattering, Electron scattering
Abstract: In the G0 experiment, performed at Jefferson Lab, the parity-violating elastic scattering of electrons from protons and quasi-elastic scattering from deuterons is measured in order to determine the neutral weak currents of the nucleon. Asymmetries as small as 1 part per million in the scattering of a polarized electron beam are determined using a dedicated apparatus. It consists of specialized beam-monitoring and control systems, a cryogenic hydrogen (or deuterium) target, and a superconducting, toroidal magnetic spectrometer equipped with plastic scintillation and aerogel Cerenkov detectors, as well as fast readout electronics for the measurement of individual events. The overall design and performance of this experimental system is discussed., Comment: Submitted to Nuclear Instruments and Methods
Published: 2011
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36. Low-energy pion scattering to1−states inC12

Author: T. Averett, Christopher Morris, J. A. McGill, J. M. Applegate, R. J. Peterson, D. S. Oakley, C. M. Kormanyos, Barry Ritchie, and J. Beck
Subjects: Nuclear reaction, Physics, Excitation function, Nuclear and High Energy Physics, Scattering, Nuclear Theory, Impulse (physics), Inelastic scattering, Mott scattering, Nuclear physics, Dipole, Pion, Atomic physics, Nuclear Experiment
Abstract: Differential cross sections for 40, 50, and 65 MeV [pi][sup +] and [pi][sup [minus]] inelastic scattering to 1[sup [minus]] excitations in [sup 12]C have been measured and compared to distorted wave impulse approximation (DWIA) reaction model predictions. Strengths are presented in terms of sum rules for the 1[sup [minus]] state at 10.84 MeV and for the giant dipole resonance from 18 to 25 MeV. An excitation function at [ital q]=224 MeV/[ital c] for the 1[sup [minus]] state at 10.84 MeV is displayed in the energy range from 50 to 291 MeV showing a non-spin-flip pattern. We find inadequacies in the detailed comparison of the shapes of the data to DWIA calculations using several standard nuclear models.
Published: 1993
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37. π++d→p+pbelow 21 MeV

Author: T. Averett, B. M. Preedom, Barry Ritchie, G. S. Blanpied, J. Tinsley, R. C. Minehart, L. C. Smith, D. Rothenberger, and K. L. Giovanetti
Subjects: Baryon, Nuclear reaction, Physics, Nuclear and High Energy Physics, Pion, Pion beam, Deuterium, Hadron, Analytical chemistry, Elementary particle, Nucleon
Abstract: Absolute total and differential cross sections for the reaction [pi][sup +]+[ital d][r arrow][ital p]+[ital p] have been measured for pion energies from 3.7 to 20.5 MeV. A crossed-field velocity separator was used to enhance the purity of the pion beam, and a deuterated scintillator was used both as the target and to count the incident flux. The total cross sections are 4.0[plus minus]0.5, 4.4[plus minus]0.2, 4.2[plus minus]0.2, 4.2[plus minus]0.2, and 4.8[plus minus]0.3 mb for incident pion energies of 3.7, 5.0, 9.6, 15.2, and 20.5 MeV, respectively. The measured differential cross sections indicate the presence of [ital p]-wave strength at all energies studied and are in good agreement with recent measurements for the reaction [ital n]+[ital p][r arrow][ital d]+[pi][sup 0] near threshold and a recent parametrization of the total and differential cross sections for the process.
Published: 1993
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38. A superconducting radio-frequency cavity for manipulating the phase space of pion beams at LAMPF

Author: Barry Ritchie, Hanspeter Vogel, G. Tubb, R. A. DeHaven, E. R. Gray, M. Peiniger, Randall P. Johnson, John M. O'Donnell, D. Kiehlmann, J. Novak, T. Averett, J. A. McGill, J. M. Applegate, Christopher Morris, H. Ward, E. Haebel, C. Fred Moore, B. J. McCloud, J. Beck, Peter Schäfer, J. Davis, U. Klein, R. E. Lomax, and B. Rusnak
Subjects: Superconductivity, Nuclear physics, Physics, Nuclear and High Energy Physics, Low energy, Pion, Pion beam, Phase space, Nuclear Theory, Superconducting radio frequency, Physics::Accelerator Physics, Instrumentation
Abstract: The SCRUNCHER is a superconducting radio-frequency cavity for manipulating the longitudinal phase space of the secondary pion beam from the low energy pion channel at LAMPF. Test results of the cavity performance and initial results from in-beam tests are presented.
Published: 1992
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39. A High-Pressure Polarized $^3$He Gas Target for Nuclear Physics Experiments Using A Polarized Photon Beam

Author: X. Zong, G. Laskaris, W. A. Tobias, T. Averett, Q. Ye, Haiyan Gao, W. Zheng, W. Chen, and G. D. Cates
Subjects: Physics, Nuclear and High Energy Physics, Photon, Polarimetry, Free-electron laser, chemistry.chemical_element, FOS: Physical sciences, Polarization (waves), Rubidium, law.invention, Nuclear physics, Optical pumping, chemistry, Photodisintegration, law, Nuclear Experiment (nucl-ex), Electron paramagnetic resonance, Nuclear Experiment
Abstract: Following the first experiment on three-body photodisintegration of polarized $^3$He utilizing circularly polarized photons from High Intensity Gamma Source (HI$\gamma$S) at Duke Free Electron Laser Laboratory (DFELL), a new high-pressure polarized $^3$He target cell made of pyrex glass coated with a thin layer of sol-gel doped with aluminum nitrate nonahydrate has been built in order to reduce the photon beam induced background. The target is based on the technique of spin-exchange optical pumping of hybrid rubidium and potassium and the highest polarization achieved is $\sim$62% determined from both NMR-AFP and EPR polarimetry. The $X$ parameter is estimated to be $\sim0.06$ and the performance of the target is in good agreement with theoretical predictions. We also present beam test results from this new target cell and the comparison with the GE180 $^3$He target cell used previously at HI$\gamma$S. This is the first time that sol-gel coating technique has been used in a polarized $^3$He target for nuclear physics experiments., Comment: 8 pages, 3 figures
Published: 2009
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40. 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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41. Parity-violating electroweak asymmetry ine⃗pscattering

Author: J. Jardillier, Baris T. Tonguc, I. Younus, G. Rutledge, V. A. Punjabi, Mauro Iodice, F. Marie, R. Michaels, G. M. Urciuoli, D. J. Margaziotis, T. Pussieux, M. Leuschner, I. K. Kominis, X. Jiang, Justin I. McIntyre, R. De Leo, M. Coman, K. Wijesooriya, J. R. Calarco, P. Mastromarino, Andre Fleck, N. Falletto, T. Averett, B. Frois, Richard Madey, Marcus Spradlin, T. B. Humensky, Paul Souder, W. Xu, Olfred Hansen, T. Teresawa, D. Relyea, J.P. Jorda, Ronald Ransome, Bogdan Wojtsekhowski, James J. Kelly, J. Gao, J. Roche, M. Liang, G. Quéméner, B. D. Milbrath, F. Sabatié, A. Gasparian, J. A. Templon, D. W. Higinbotham, C. C. Chang, Kevin Fissum, M. B. Epstein, K. S. Kumar, J. Thompson, R. J. Woo, L. Todor, Gordon D. Cates, R. I. Pomatsalyuk, D. S. Dale, R. W. Lourie, J. M. Finn, A. Saha, John C. Mitchell, R. Suleiman, G. W. Miller, Daijin Kim, C. Jutier, R. Holmes, Sebastien Incerti, S. Malov, E. Burtin, M. Holtrop, W. Kahl, S. Strauch, P. E. Ulmer, P. Markowitz, S. Frullani, M. J. Kim, P. M. Rutt, Y. Roblin, D. Lhuillier, David L. Prout, G. M. Gerstner, Min Suk Kim, Jian-Ping Chen, F. Garibaldi, D. S. Armstrong, J. J. LeRose, K. Kramer, V. Gorbenko, M. Rvachev, J. Martino, G. G. Petratos, Edgar E. Kooijman, Z. E. Meziani, C. W. de Jager, K. A. Aniol, D. Neyret, Raphael Noel Tieulent, M. Baylac, F. W. Hersman, L. A. Ewell, J. S. Price, C. Cavata, Nilanga Liyanage, A. V. Glamazdin, Z. Chai, Richard Wilson, Branislav Vlahovic, E. Cisbani, J. Gomez, C. Zhang, L. Morand, Ronald Gilman, K. McCormick, E. Chudakov, P. Djawotho, Stephanie Escoffier, M. K. Jones, C. Pedrisat, M. Kuss, and A. Deur
Subjects: Nuclear reaction, Elastic scattering, Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, media_common.quotation_subject, Hadron, Elementary particle, 01 natural sciences, Asymmetry, Baryon, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Nucleon, media_common, Lepton
Abstract: We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from protons. Significant contributions to this asymmetry could arise from the contributions of strange form factors in the nucleon. The measured asymmetry is $A=\ensuremath{-}15.05\ifmmode\pm\else\textpm\fi{}0.98(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.56(\mathrm{syst})\phantom{\rule{0.3em}{0ex}}\mathrm{ppm}$ at the kinematic point $⟨{\ensuremath{\theta}}_{\mathrm{lab}}⟩=12.3\ifmmode^\circ\else\textdegree\fi{}$ and $⟨{Q}^{2}⟩=0.477\phantom{\rule{0.3em}{0ex}}{(\mathrm{GeV}∕c)}^{2}$. Based on these data as well as data on electromagnetic form factors, we extract the linear combination of strange form factors ${G}_{E}^{s}+0.392{G}_{M}^{s}=0.014\ifmmode\pm\else\textpm\fi{}0.020\ifmmode\pm\else\textpm\fi{}0.010$, where the first error arises from this experiment and the second arises from the electromagnetic form factor data. This paper provides a full description of the special experimental techniques employed for precisely measuring the small asymmetry, including the first use of a strained GaAs crystal and a laser-Compton polarimeter in a fixed target parity-violation experiment.
Published: 2004
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42. Precision Measurement of the Neutron Spin Asymmetries and Spin-dependent Structure Functions in the Valence Quark Region

Author: Z. Chai, Douglas Higinbotham, G. M. Urciuoli, J. R. Calarco, L. J. Kaufman, D. J. Margaziotis, T. Averett, V. Sulkosky, Baile Zhang, S. K. Nanda, W. Hinton, Haiyan Gao, B. Reitz, Dipangkar Dutta, Bogdan Wojtsekhowski, E. Chudakov, Paul Souder, Nilanga Liyanage, Jaideep Singh, J. O. Hansen, Sonja Dieterich, L. Zhu, F. Garibaldi, D. S. Armstrong, F. Cusanno, F. Marie, Karl Slifer, C. Butuceanu, William Bertozzi, Z. E. Meziani, A. Deur, Jiansong Gao, D. J. Steiner, A. Powell, Seonho Choi, Jian-Ping Chen, K. McCormick, Pete Markowitz, J. Gomez, P. Solvignon, E. Burtin, J. LeRose, Ronald Gilman, R. De Leo, A. Camsonne, Arijit Saha, S. Frullani, J. M. Finn, X. Zheng, D. Lhuillier, Xiaofeng Zhu, Guy Ron, F. Xiong, S. Širca, S. Strauch, D. Neyret, Antonin Vacheret, T. Horn, S. Binet, Wolfgang Korsch, Hua Xiang, M. Roedelbronn, R. Roche, T. Pussieux, X. Jiang, M. Rvachev, Y. Xiao, Emmanuel Busato, Gordon D. Cates, S. K. Phillips, Shalev Gilad, C. W. de Jager, K. A. Aniol, R. Michaels, Bryan J. Moffit, J. Roche, P. A. Zolnierczuk, James J. Kelly, N. Savvinov, K. Kramer, Adam M. Tobias, 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), and HALL A
Subjects: Nuclear and High Energy Physics, Particle physics, Hadron, Constituent quark, FOS: Physical sciences, Parton, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, High Energy Physics - Experiment, 13.60.Hb, 24.85.+p, 25.30.-c, Nuclear physics, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Quantum chromodynamics, Physics, 010308 nuclear & particles physics, Perturbative QCD, Deep inelastic scattering, Baryon, High Energy Physics - Phenomenology, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], High Energy Physics::Experiment, Nucleon
Abstract: We report on measurements of the neutron spin asymmetries $A_{1,2}^n$ and polarized structure functions $g_{1,2}^n$ at three kinematics in the deep inelastic region, with $x=0.33$, 0.47 and 0.60 and $Q^2=2.7$, 3.5 and 4.8 (GeV/c)$^2$, respectively. These measurements were performed using a 5.7 GeV longitudinally-polarized electron beam and a polarized $^3$He target. The results for $A_1^n$ and $g_1^n$ at $x=0.33$ are consistent with previous world data and, at the two higher $x$ points, have improved the precision of the world data by about an order of magnitude. The new $A_1^n$ data show a zero crossing around $x=0.47$ and the value at $x=0.60$ is significantly positive. These results agree with a next-to-leading order QCD analysis of previous world data. The trend of data at high $x$ agrees with constituent quark model predictions but disagrees with that from leading-order perturbative QCD (pQCD) assuming hadron helicity conservation. Results for $A_2^n$ and $g_2^n$ have a precision comparable to the best world data in this kinematic region. Combined with previous world data, the moment $d_2^n$ was evaluated and the new result has improved the precision of this quantity by about a factor of two. When combined with the world proton data, polarized quark distribution functions were extracted from the new $g_1^n/F_1^n$ values based on the quark parton model. While results for $\Delta u/u$ agree well with predictions from various models, results for $\Delta d/d$ disagree with the leading-order pQCD prediction when hadron helicity conservation is imposed., Comment: A typing error in A_\parallel(3He) at x=0.47 in Table VII of Phys. Rev. C has been noticed and corrected
Published: 2004
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43. Cross Section Measurements of Charged Pion Photoproduction in Hydrogen and Deuterium from 1.1 to 5.5 GeV

Author: P. E. Reimer, E. Chudakov, R. Michaels, S. K. Nanda, B. Reitz, V. Sulkosky, Sonja Dieterich, S. Strauch, W. Xu, Olfred Hansen, K. McCormick, X. Zheng, Douglas Higinbotham, X. Jiang, John C. Mitchell, Nilanga Liyanage, Jian-Ping Chen, E. R. Kinney, S. Frullani, R. J. Holt, C. F. Williamson, L. Zhu, Haiyan Gao, Branislav Vlahovic, C. Glashausser, Kevin Fissum, Benjamin Clasie, K. Hafidi, D. J. Mack, K. Wijesooriya, J. Zeng, E. Schulte, J. Calarco, J. Gomez, P. Markowitz, Z. E. Meziani, C. Crawford, Bogdan Wojtsekhowski, G. J. Kumbartzki, H. Xiang, K. Kramer, F. Dohrmann, D. H. Potterveld, M. Coman, Ronald Gilman, F. Xiong, Dipanwita Dutta, C. W. de Jager, Ronald Ransome, T. Chang, J. Seely, John Arrington, Arijit Saha, D. G. Meekins, S. Širca, E. J. Beise, J. LeRose, Larry Weinstein, and T. Averett
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Photon, Sigma, FOS: Physical sciences, Gluon, Nuclear physics, Cross section (physics), symbols.namesake, Pion, Deuterium, symbols, Feynman diagram, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment, Scaling
Abstract: The differential cross section for the gamma +n --> pi- + p and the gamma + p --> pi+ n processes were measured at Jefferson Lab. The photon energies ranged from 1.1 to 5.5 GeV, corresponding to center-of-mass energies from 1.7 to 3.4 GeV. The pion center-of-mass angles varied from 50 degree to 110 degree. The pi- and pi+ photoproduction data both exhibit a global scaling behavior at high energies and high transverse momenta, consistent with the constituent counting rule prediction and the existing pi+ data. The data suggest possible substructure of the scaling behavior, which might be oscillations around the scaling value. The data show an enhancement in the scaled cross section at center-of-mass energy near 2.2 GeV. The differential cross section ratios at high energies and high transverse momenta can be described by calculations based on one-hard-gluon-exchange diagrams., 18 pages, 19 figures
Published: 2004
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44. Basic instrumentation for Hall A at Jefferson Lab

Author: T. Pussieux, Paul Souder, J. H. Mitchell, Y. Roblin, O. Ravel, E. Chudakov, K. A. Griffioen, C. Cavata, J. A. Templon, H. F. Ibrahim, J. S. McCarthy, M. A. Stevens, D. P. Watts, B. Frois, W. J. Schneider, Dipangkar Dutta, R. Di Salvo, R. I. Pomatsalyuk, A. Soldi, G. J. Kumbartzki, Arijit Saha, N. Colombel, J. Berthot, Jing Zhao, A. J. Sarty, B. D. Anderson, J. Martine, M. Coman, R. Michaels, M. B. Epstein, R. W. Lourie, J. O. Hansen, N. Degrande, J. Mclntyre, John Arrington, L. Zhu, W. Kahl, Bogdan Wojtsekhowski, P. Djawotho, M. Leuschner, William Bertozzi, K. A. Aniol, A. Gasparian, Karl Slifer, Jrm Annand, C. F. Perdrisat, D. Pripstein, M. Baylac, S. Kox, X. Jiang, K. Kramer, H. Breuer, David Hamilton, Jian-Ping Chen, T. Averett, L. B. Auerbach, G. A. Rutledge, G. Quéméner, Stephanie Escoffier, P.Y. Bertin, R. Suleiman, R. Carr, Pete Markowitz, A. Deur, Z. Papandreou, R. L. Walter, R. D. McKeown, T. P. Gorringe, M. Rvachev, R. Holmes, S. Churchwell, J. Marroncle, S. Platchkov, M. Khandaker, M. Liang, L. Pierangeli, K. Kino, A. Ketikyan, Kevin Fissum, F. W. Hersman, J. LeRose, F. Giuliani, P. E. Ulmer, Roberto Perrino, R. De Leo, J. Gao, L. A. Ewell, S. Jensen, R. Crateri, Shalev Gilad, C. W. de Jager, D. Lhuillier, J.E. Ducret, M. Gricia, R. Iommi, F. Sabatavenere, P. A. Zolnierczuk, K. Wijesooriya, Alan M. Nathan, D. Rowntree, E. Voutier, H. Holmgren, S. K. Nanda, D. G. Meekins, K. S. Egiyan, C. R. Howell, A. Serdarevic-Offermann, Hiroaki Tsubota, D. G. Zainea, J. R. Calarco, S. Esp, T. Terasawa, Vincent Breton, C. C. Chang, J. Domingo, T. Black, A. T. Katramatou, S. Kerhoas, F. Santavenere, J. Y. Mougey, R. Van de Vyver, G. M. Urciuoli, Seigo Kato, G. M. Huber, B. Reitz, E. J. Beise, K. S. Kumar, F. Garibaldi, Pavel Sorokin, G. J. Lolos, M. Lucentini, J. Segal, H. Xiang, D. V. Boykin, W. U. Boeglin, C. Glashausser, E. Cisbani, A. Leone, R. D. Ransomez, Gordon D. Cates, Sonja Dieterich, H. Voskanyan, C. Jutier, R. L.J. van der Meer, Olivier Gayou, James A. Miller, L. Van Hoorebeke, Sebastien Incerti, J. Jardillier, L. Cardman, James J. Kelly, F. Xiong, S. Jaminion, I. K. Kominis, K. McCormick, P. Vernin, P. M. Rutt, A. Petrosyan, David L. Prout, Nilanga Liyanage, L. Lagamba, X. Zheng, S. L. Spiegel, Branislav Vlahovic, Leonid Levchuk, Mauro Iodice, Larry Weinstein, F. Marie, D. G. Ireland, N. S. Chant, David Manley, V. A. Punjabi, C. E. Jones, J. Gomez, Wolfgang Korsch, W. Xu, J. W. Watson, M. Roedelbronn, F. T. Baker, Z. E. Meziani, T. Saito, S. Frullani, H. Ueno, E. J. Brash, R. Roche, E. Hovhannisyan, C. E. Hyde-Wright, N. d'Hose, L. Bimbot, G. Laveissière, R. Madey, Kazushige Maeda, A. Gavalya, W. Miller, D. Neyret, T. P. Smith, B. Diederich, E. Burtin, M. Holtrop, L. Todor, G. Dezern, Z. L. Zhou, K. Livingston, D. S. Dale, V. Zeps, S. Mayilyan, E. Folts, B. D. Milbrath, Haiyan Gao, J. M. Finn, O. Rondon-Aramayo, R. A. Lindgren, V. Gorbenko, A. V. Glamazdin, Z. Chai, E. A.J.M. Offermann, S. Malov, J. Alcorn, S. Strauch, A. Shahinyan, G. Rosner, H. Fonvieille, P. G. Roos, E. W. Hughes, K. Joo, D. S. Brown, P. Brindza, G. G. Petratos, S. van Verst, M. Khayat, S. Colilli, Douglas Higinbotham, M. K. Jones, D. J. Margaziotis, M. Kuss, Seonho Choi, Ronald Gilman, Thomas Jefferson National Accelerator Facility (Jefferson Lab), 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), 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 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), HALL A, 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), and 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)
Subjects: Physics, Nuclear and High Energy Physics, Spectrometer, 010308 nuclear & particles physics, Cryogenics, Scintillator, 7. Clean energy, 01 natural sciences, Particle identification, Magnetic field, Nuclear physics, Cardinal point, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Nuclear Experiment, 010306 general physics, Nucleon, Instrumentation, Cherenkov radiation
Abstract: The instrumentation in Hall A at the Thomas Jefferson National Accelerator Facility was designed to study electro-and photo-induced reactions at very high luminosity and good momentum and angular resolution for at least one of the reaction products. The central components of Hall A are two identical high resolution spectrometers, which allow the vertical drift chambers in the focal plane to provide a momentum resolution of better than 2 x 10(-4). A variety of Cherenkov counters, scintillators and lead-glass calorimeters provide excellent particle identification. The facility has been operated successfully at a luminosity well in excess of 10(38) CM-2 s(-1). The research program is aimed at a variety of subjects, including nucleon structure functions, nucleon form factors and properties of the nuclear medium. (C) 2003 Elsevier B.V. All rights reserved.
Published: 2004
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45. Nuclear transparency with theγn→π−pprocess in4He

Author: C. F. Williamson, R. J. Holt, Douglas Higinbotham, E. Schulte, J. J. LeRose, M. Coman, K. Wijesooriya, E. R. Kinney, V. Sulkosky, John C. Mitchell, Z. E. Meziani, A. Saha, Bogdan Wojtsekhowski, W. Xu, S. Frullani, L. Y. Zhu, K. Kramer, Kevin Fissum, D. J. Mack, P. E. Reimer, C. W. de Jager, J. Seely, J. Zeng, G. J. Kumbartzki, Haiyan Gao, D. H. Potterveld, X. Zheng, S. K. Nanda, F. Dohrmann, J. R. Calarco, Benjamin Clasie, R. Michaels, Christopher Crawford, Dipanwita Dutta, K. McCormick, J. A. Gomez, Simon Širca, Sonja Dieterich, T. Averett, J. Arrington, C. Glashausser, S. Strauch, F. Xiong, E. Chudakov, Nilanga Liyanage, K. Hafidi, B. Reitz, Branislav Vlahovic, Ronald Ransome, X. Jiang, E. J. Beise, J.-O. Hansen, Larry Weinstein, Ronald Gilman, Pete Markowitz, J. P. Chen, H. Xiang, and T. Chang
Subjects: Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, Nuclear transparency, Nuclear Theory, Momentum transfer, Color transparency, Photon energy, Nuclear Experiment, Glauber
Abstract: We have measured the nuclear transparency of the fundamental process $\ensuremath{\gamma}\stackrel{\ensuremath{\rightarrow}}{n}{\ensuremath{\pi}}^{\ensuremath{-}}p$ in ${}^{4}\mathrm{He}.$ These measurements were performed at Jefferson Lab in the photon energy range of 1.6--4.5 GeV and at ${\ensuremath{\theta}}_{\mathrm{cm}}^{\ensuremath{\pi}}=70\ifmmode^\circ\else\textdegree\fi{}$ and $90\ifmmode^\circ\else\textdegree\fi{}.$ These measurements are the first of their kind in the study of nuclear transparency in photoreactions. They also provide a benchmark test of Glauber calculations based on traditional models of nuclear physics. The transparency results suggest deviations from the traditional nuclear physics picture. The momentum transfer dependence of the measured nuclear transparency is consistent with Glauber calculations that include the quantum chromodynamics phenomenon of color transparency.
Published: 2003
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46. Plane-wave impulse approximation extraction of the neutron magnetic form factor from quasielastic3He→(e→,e′)atQ2=0.3to0.6(GeV/c)2

Author: G. G. Petratos, Z. E. Meziani, J. M. Finn, A. Saha, W. Xu, J. P. Chen, D. Pripstein, J. S. Jensen, C. E. Jones, K. McCormick, Dipangkar Dutta, C. R. Howell, P. Żołnierczuk, S. Churchwell, A. Kievsky, R. I. Pomatsalyuk, J. R. Calarco, Ronald Ransome, G. S. Corrado, T. Black, Sebastien Incerti, K. Kramer, E. Chudakov, Emanuele Pace, R. Holmes, John C. Mitchell, T.W. Donnelly, D. S. Dale, M. K. Jones, Gordon D. Cates, K. McIlhany, E. Lakuriqi, T. Averett, M. Liang, J. O. Hansen, G. J. Kumbartzki, B. D. Anderson, Jacek Golak, Bogdan Wojtsekhowski, W. Glöckle, F. W. Hersman, S. Strauch, P. Djawotho, E. W. Hughes, D. W. Higinbotham, B. Humensky, Haiyan Gao, D. J. Margaziotis, C. F. Williamson, L. Auberbach, C. Glashausser, Karl Slifer, M. Sutter, J. Yeh, M. Viviani, Wolfgang Korsch, S. K. Nanda, M. Kuss, I. K. Kominis, C. W. de Jager, B. Tipton, William Bertozzi, F. Xiong, C. Crawford, J. W. Watson, Nilanga Liyanage, A. Deur, Hiroyuki Kamada, R. D. McKeown, R. Michaels, G. Salme, Y. Roblin, Branislav Vlahovic, Seonho Choi, L. S. Cardman, R. Suleiman, R. Kahl, L. Todor, S. Malov, J. Gomez, M. Schnee, J. W. Martin, Henryk Witała, Ronald Gilman, Paul Souder, T. Pavlin, G. W. Miller, David L. Prout, X. Jiang, M. Rvachev, T. Shin, A. V. Glamazdin, Z. Chai, J. J. LeRose, and V. Gorbenko
Subjects: Physics, Nuclear physics, Nuclear reaction, Nuclear and High Energy Physics, Quasielastic scattering, Scattering, Magnetic form factor, Hadron, Momentum transfer, Neutron, Nuclear Experiment, Nucleon
Abstract: A high precision measurement of the transverse spin-dependent asymmetry A_T' in ^3He(e,e') quasielastic scattering was performed in Hall A at Jefferson Lab at values of the squared four-momentum transfer, Q^2, between 0.1 and 0.6 (GeV/c)^2. A_(T') is sensitive to the neutron magnetic form factor, G_M^n . Values of G_M^n at Q^2 = 0.1 and 0.2 (GeV/c)^2, extracted using Faddeev calculations, were reported previously. Here, we report the extraction of G_M^n for the remaining Q^2 values in the range from 0.3 to 0.6 (GeV/c)^2 using a plane-wave impulse approximation calculation. The results are in good agreement with recent precision data from experiments using a deuterium target.
Published: 2003
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47. The Strange Quark Contribution to the Proton's Magnetic Moment

Author: Michael J. Ramsey-Musolf, B. Mueller, W. Franklin, S. Covrig, H. Breuer, Raphael Noel Tieulent, R. Carr, Evgeni Tsentalovich, S. Wells, G. W. Dodson, K. A. Dow, Bao Yang, B. W. Filippone, T. Zwart, T. Averett, Takeyasu M. Ito, R. Hasty, Douglas H Beck, S. Kowalski, D. Barkhuff, Wolfgang Korsch, R. D. McKeown, J. Ritter, M. Farkhondeh, Michael Pitt, D. T. Spayde, and E. J. Beise
Subjects: Quark, Physics, Quantum chromodynamics, Elastic scattering, Nuclear and High Energy Physics, Particle physics, Strange quark, Proton, Magnetic moment, 010308 nuclear & particles physics, Proton magnetic moment, FOS: Physical sciences, 01 natural sciences, Nuclear physics, 0103 physical sciences, Magnetic form factor, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment
Abstract: We report a new determination of the strange quark contribution to the proton's magnetic form factor at a four-momentum transfer Q2 = 0.1 (GeV/c)^2 from parity-violating e-p elastic scattering. The result uses a revised analysis of data from the SAMPLE experiment which was carried out at the MIT-Bates Laboratory. The data are combined with a calculation of the proton's axial form factor GAe to determine the strange form factor GMs(Q2=0.1)=0.37 +- 0.20 +- 0.26 +- 0.07. The extrapolation of GMs to its Q2=0 limit and comparison with calculations is also discussed., Comment: 6 pages, 1 figure, submitted to Phys. Lett. B
Published: 2003
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48. Spin correlation measurements forp→+p→ elastic scattering at 497.5 MeV

Author: G. Pauletta, Gerald W Hoffmann, D. Mihailidis, M. Purcell, A. M. Mack, J. Görgen, N. Tanaka, James F. Amann, J. R. Comfort, J. Tinsley, W. Kielhorn, M. Gilani, J. J. Jarmer, G. S. Kyle, Martin L Barlett, T. Averett, L. Stevens, Lanny Ray, S. I. Penttilä, K. W. Jones, J. A. Faucett, and G. R. Burleson
Subjects: Elastic scattering, Nuclear reaction, Physics, Nuclear and High Energy Physics, Angular momentum, Proton, Scattering, Computer Science::Information Retrieval, Nuclear Theory, Forward angle, Amplitude, Atomic physics, Nuclear Experiment, Spin-½
Abstract: The spin correlation parameter [ital A][sub 00[ital N][ital N]] for 497.5 MeV proton + proton elastic scattering was determined over the center-of-momentum scattering angle region 23.1[degree]--64.9 [degree]. The new [ital A][sub 00[ital N][ital N]] extend to more forward angles than existing [ital A][sub 00[ital N][ital N]] and have significantly smaller statistical errors ([plus minus]0.01--0.04). The [ital A][sub 00[ital N][ital N]] are qualitatively described by recent phase shift analyses, but a quantitative shape and normalization discrepancy remains in the forward angle region. These new data provide important constraints for nucleon-nucleon spin-dependent amplitudes at forward angles which are used in theoretical models of nucleon-nucleus scattering.
Published: 1994
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49. Precision Measurement of the Proton and Deuteron Spin Structure Functions g2 and Asymmetries A2

Author: P.L. Anthony, R.G. Arnold, T. Averett, H.R. Band, N. Benmouna, W. Boeglin, H. Borel, P.E. Bosted, S.L. Bültmann, G.R. Court, D. Crabb, D. Day, P. Decowski, P. DePietro, H. Egiyan, R. Erbacher, R. Erickson, R. Fatemi, E. Frlez, K.A. Griffioen, C. Harris, E.W. Hughes, C. Hyde-Wright, G. Igo, J. Johnson, P. King, K. Kramer, S.E. Kuhn, D. Lawrence, Y. Liang, R. Lindgren, R.M. Lombard-Nelsen, P. McKee, D.E. McNulty, W. Meyer, G.S. Mitchell, J. Mitchell, M. Olson, S. Penttila, G.A. Peterson, R. Pitthan, D. Pocanic, R. Prepost, C. Prescott, B.A. Raue, D. Reyna, P. Ryan, L.S. Rochester, S. Rock, O. Rondon-Aramayo, F. Sabatie, T. Smith, L. Sorrell, S.St. Lorant, Z. Szalata, Y. Terrien, A. Tobias, T. Toole, S. Trentalange, F.R. Wesselmann, T.R. Wright, M. Zeier, H. Zhu, and B. Zihlmann
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Range (particle radiation), Proton, 010308 nuclear & particles physics, Virtual particle, FOS: Physical sciences, Absolute value, Kinematics, Spin structure, 01 natural sciences, 3. Good health, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Deuterium, 0103 physical sciences, Limit (mathematics), 010306 general physics
Abstract: We have measured the spin structure functions g2p and g2d and the virtual photon asymmetries A2p and A2d over the kinematic range 0.02 < x < 0.8 and 0.7 < Q^2 < 20 GeV^2 by scattering 29.1 and 32.3 GeV longitudinally polarized electrons from transversely polarized NH3 and 6LiD targets. Our measured g2 approximately follows the twist-2 Wandzura-Wilczek calculation. The twist-3 reduced matrix elements d2p and d2n are less than two standard deviations from zero. The data are inconsistent with the Burkhardt-Cottingham sum rule if there is no pathological behavior as x->0. The Efremov-Leader-Teryaev integral is consistent with zero within our measured kinematic range. The absolute value of A2 is significantly smaller than the sqrt[R(1+A1)/2] limit., 12 pages, 4 figures, 2 tables
Published: 2002

50. xandξscaling of the nuclear structure function at largex

Author: J. Zhao, D. Koltenuk, Ingo Sick, C. E. Keppel, W. F. Vulcan, B. Zihlmann, D. G. Crabb, A. Honegger, Curtis Smith, B. Bray, J. Jourdan, G. Niculescu, B. W. Filippone, Dipangkar Dutta, Donal Day, J. H. Mitchell, B. Terburg, C. S. Armstrong, J. Arrington, T. Averett, James McCarthy, G. Collins, J. Jensen, R. A. Lindgren, A. Lung, R. D. Carlini, O. Rondon, I. Niculescu, S. A. Wood, W.U. Boeglin, C. Cothran, D. J. Mack, T. Petitjean, R. D. McKeown, C. Yan, H. Mkrtchyan, Oliver Keith Baker, L.J. de Bever, J. A. Dunne, D. G. Meekins, C. Bochna, E. W. Hughes, and Rolf Ent
Subjects: Physics, Momentum, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Scattering, Momentum transfer, Nuclear structure, Inelastic scattering, Nuclear Experiment, Nucleon, Electron scattering, Scaling
Abstract: Inclusive electron scattering data are presented for ^2H, C, Fe, and Au targets at an incident electron energy of 4.045 GeV for a range of momentum transfers from Q^2=1 to 7 (GeV/c)^2. Data were taken at Jefferson Laboratory for low values of energy loss, corresponding to values of Bjorken x ≳ 1. The structure functions do not show scaling in x in this range, where inelastic scattering is not expected to dominate the cross section. The data do show scaling, however, in the Nachtmann variable ξ. This scaling appears to be the result of Bloom- Gilman duality in the nucleon structure function combined with the Fermi motion of the nucleons in the nucleus. The resulting extension of scaling to larger values of ξ opens up the possibility of accessing nuclear structure functions in the high-x region at lower values of Q^2 than previously believed.
Published: 2001
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