E. Piasetzky - Jefferson Lab Hall A Collaboration

E. Piasetzky
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E. Piasetzky
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Jefferson Lab Hall A Collaboration
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Nuclear Experiment (47)
 
Nuclear Theory (20)
 
High Energy Physics - Phenomenology (10)
 
High Energy Physics - Experiment (9)
 
Physics - Instrumentation and Detectors (3)
 
Solar and Stellar Astrophysics (2)
 
High Energy Astrophysical Phenomena (1)

Publications Authored By E. Piasetzky

2017May
Authors: MicroBooNE collaboration, R. Acciarri, C. Adams, R. An, J. Anthony, J. Asaadi, M. Auger, L. Bagby, S. Balasubramanian, B. Baller, C. Barnes, G. Barr, M. Bass, F. Bay, M. Bishai, A. Blake, T. Bolton, B. Bullard, L. Camilleri, D. Caratelli, B. Carls, R. Castillo Fernandez, F. Cavanna, H. Chen, E. Church, D. Cianci, E. Cohen, G. H. Collin, J. M. Conrad, M. Convery, J. I. Crespo-Anadon, G. De Geronimo, M. Del Tutto, D. Devitt, S. Dytman, B. Eberly, A. Ereditato, L. Escudero Sanchez, J. Esquivel, A. A. Fadeeva, B. T. Fleming, W. Foreman, A. P. Furmanski, D. Garcia-Gamez, G. T. Garvey, V. Genty, D. Goeldi, S. Gollapinni, N. Graf, E. Gramellini, H. Greenlee, R. Grosso, R. Guenette, A. Hackenburg, P. Hamilton, O. Hen, J. Hewes, C. Hill, J. Ho, G. Horton-Smith, A. Hourlier, E. -C. Huang, C. James, J. Jan de Vries, C. -M. Jen, L. Jiang, R. A. Johnson, J. Joshi, H. Jostlein, D. Kaleko, G. Karagiorgi, W. Ketchum, B. Kirby, M. Kirby, T. Kobilarcik, I. Kreslo, A. Laube, S. Li, Y. Li, A. Lister, B. R. Littlejohn, S. Lockwitz, D. Lorca, W. C. Louis, M. Luethi, B. Lundberg, X. Luo, A. Marchionni, C. Mariani, J. Marshall, D. A. Martinez Caicedo, V. Meddage, T. Miceli, G. B. Mills, J. Moon, M. Mooney, C. D. Moore, J. Mousseau, R. Murrells, D. Naples, P. Nienaber, J. Nowak, O. Palamara, V. Paolone, V. Papavassiliou, S. F. Pate, Z. Pavlovic, E. Piasetzky, D. Porzio, G. Pulliam, X. Qian, J. L. Raaf, V. Radeka, A. Rafique, S. Rescia, L. Rochester, C. Rudolf von Rohr, B. Russell, D. W. Schmitz, A. Schukraft, W. Seligman, M. H. Shaevitz, J. Sinclair, A. Smith, E. L. Snider, M. Soderberg, S. Soldner-Rembold, S. R. Soleti, P. Spentzouris, J. Spitz, J. St. John, T. Strauss, A. M. Szelc, N. Tagg, K. Terao, M. Thomson, C. Thorn, M. Toups, Y. -T. Tsai, S. Tufanli, T. Usher, W. Van De Pontseele, R. G. Van de Water, B. Viren, M. Weber, D. A. Wickremasinghe, S. Wolbers, T. Wongjirad, K. Woodruff, T. Yang, L. Yates, B. Yu, G. P. Zeller, J. Zennamo, C. Zhang

The low-noise operation of readout electronics in a liquid argon time projection chamber (LArTPC) is critical to properly extract the distribution of ionization charge deposited on the wire planes of the TPC, especially for the induction planes. This paper describes the characteristics and mitigation of the observed noise in the MicroBooNE detector. The MicroBooNE's single-phase LArTPC comprises two induction planes and one collection sense wire plane with a total of 8256 wires. Read More

$[Background]$ Measurements of the neutron charge distribution are made difficult by the fact that, with no net charge, the neutron electric form factor, $G^n_E$, is generally much smaller than the magnetic form factor, $G^n_M$. In addition, measurements of these form factors must use nuclear targets which requires accurately accounting for nuclear effects. $[Method]$ The inclusive quasi-elastic reaction $^3\overrightarrow{\rm{He}}(\overrightarrow{e},e')$ was measured at Jefferson Lab. Read More

2017Apr
Authors: MicroBooNE collaboration, R. Acciarri, C. Adams, R. An, J. Anthony, J. Asaadi, M. Auger, L. Bagby, S. Balasubramanian, B. Baller, C. Barnes, G. Barr, M. Bass, F. Bay, M. Bishai, A. Blake, T. Bolton, L. Bugel, L. Camilleri, D. Caratelli, B. Carls, R. Castillo Fernandez, F. Cavanna, H. Chen, E. Church, D. Cianci, E. Cohen, G. H. Collin, J. M. Conrad, M. Convery, J. I. Crespo-Anadon, M. Del Tutto, D. Devitt, S. Dytman, B. Eberly, A. Ereditato, L. Escudero Sanchez, J. Esquivel, B. T. Fleming, W. Foreman, A. P. Furmanski, D. Garcia-Gamez, G. T. Garvey, V. Genty, D. Goeldi, S. Gollapinni, N. Graf, E. Gramellini, H. Greenlee, R. Grosso, R. Guenette, A. Hackenburg, P. Hamilton, O. Hen, J. Hewes, C. Hill, J. Ho, G. Horton-Smith, E. -C. Huang, C. James, J. Jan de Vries, C. -M. Jen, L. Jiang, R. A. Johnson, J. Joshi, H. Jostlein, D. Kaleko, G. Karagiorgi, W. Ketchum, B. Kirby, M. Kirby, T. Kobilarcik, I. Kreslo, A. Laube, Y. Li, A. Lister, B. R. Littlejohn, S. Lockwitz, D. Lorca, W. C. Louis, M. Luethi, B. Lundberg, X. Luo, A. Marchionni, C. Mariani, J. Marshall, D. A. Martinez Caicedo, V. Meddage, T. Miceli, G. B. Mills, J. Moon, M. Mooney, C. D. Moore, J. Mousseau, R. Murrells, D. Naples, P. Nienaber, J. Nowak, O. Palamara, V. Paolone, V. Papavassiliou, S. F. Pate, Z. Pavlovic, E. Piasetzky, D. Porzio, G. Pulliam, X. Qian, J. L. Raaf, A. Rafique, L. Rochester, C. Rudolf von Rohr, B. Russell, D. W. Schmitz, A. Schukraft, W. Seligman, M. H. Shaevitz, J. Sinclair, E. L. Snider, M. Soderberg, S. Soldner-Rembold, S. R. Soleti, P. Spentzouris, J. Spitz, J. St. John, T. Strauss, K. A. Sutton, A. M. Szelc, N. Tagg, K. Terao, M. Thomson, M. Toups, Y. -T. Tsai, S. Tufanli, T. Usher, R. G. Van de Water, B. Viren, M. Weber, D. A. Wickremasinghe, S. Wolbers, T. Wongjirad, K. Woodruff, T. Yang, L. Yates, G. P. Zeller, J. Zennamo, C. Zhang

The MicroBooNE liquid argon time projection chamber (LArTPC) has been taking data at Fermilab since 2015 collecting, in addition to neutrino beam, cosmic-ray muons. Results are presented on the reconstruction of Michel electrons produced by the decay at rest of cosmic-ray muons. Michel electrons are abundantly produced in the TPC, and given their well known energy spectrum can be used to study MicroBooNE's detector response to low-energy electrons (electrons with energies up to ~50 MeV). Read More

2017Mar
Authors: MicroBooNE collaboration, P. Abratenko, R. Acciarri, C. Adams, R. An, J. Asaadi, M. Auger, L. Bagby, S. Balasubramanian, B. Baller, C. Barnes, G. Barr, M. Bass, F. Bay, M. Bishai, A. Blake, T. Bolton, L. Bugel, L. Camilleri, D. Caratelli, B. Carls, R. Castillo Fernandez, F. Cavanna, H. Chen, E. Church, D. Cianci, E. Cohen, G. H. Collin, J. M. Conrad, M. Convery, J. I. Crespo-Anadon, M. Del Tutto, D. Devitt, S. Dytman, B. Eberly, A. Ereditato, L. Escudero Sanchez, J. Esquivel, B. T. Fleming, W. Foreman, A. P. Furmanski, D. Garcia-Gomez, G. T. Garvey, V. Genty, D. Goeldi, S. Gollapinni, N. Graf, E. Gramellini, H. Greenlee, R. Grosso, R. Guenette, A. Hackenburg, P. Hamilton, O. Hen, J. Hewes, C. Hill, J. Ho, G. Horton-Smith, E. -C. Huang, C. James, J. Jan de Vries, C. -M. Jen, L. Jiang, R. A. Johnson, B. J. P. Jones, J. Joshi, H. Jostlein, D. Kaleko, L. N. Kalousis, G. Karagiorgi, W. Ketchum, B. Kirby, M. Kirby, T. Kobilarcik, I. Kreslo, A. Laube, Y. Li, A. Lister, B. R. Littlejohn, S. Lockwitz, D. Lorca, W. C. Louis, M. Luethi, B. Lundberg, X. Luo, A. Marchionni, C. Mariani, J. Marshall, D. A. Martinez Caicedo, V. Meddage, T. Miceli, G. B. Mills, J. Moon, M. Mooney, C. D. Moore, J. Mousseau, R. Murrells, D. Naples, P. Nienaber, J. Nowak, O. Palamara, V. Paolone, V. Papavassiliou, S. F. Pate, Z. Pavlovic, E. Piasetzky, D. Porzio, G. Pulliam, X. Qian, J. L. Raaf, A. Rafique, L. Rochester, C. Rudolf von Rohr, B. Russell, D. W. Schmitz, A. Schukraft, W. Seligman, M. H. Shaevitz, J. Sinclair, E. L. Snider, M. Soderberg, S. Soldner-Rembold, S. R. Soleti, P. Spentzouris, J. Spitz, J. St. John, T. Strauss, A. M. Szelc, N. Tagg, K. Terao, M. Thomson, M. Toups, Y. -T. Tsai, S. Tufanli, T. Usher, R. G. Van de Water, B. Viren, M. Weber, J. Weston, D. A. Wickremasinghe, S. Wolbers, T. Wongjirad, K. Woodruff, T. Yang, L. Yates, G. P. Zeller, J. Zennamo, C. Zhang

We discuss a technique for measuring a charged particle's momentum by means of multiple Coulomb scattering (MCS) in the MicroBooNE liquid argon time projection chamber (LArTPC). This method does not require the full particle ionization track to be contained inside of the detector volume as other track momentum reconstruction methods do (range-based momentum reconstruction and calorimetric momentum reconstruction). We motivate use of this technique, describe a tuning of the underlying phenomenological formula, quantify its performance on fully contained beam-neutrino-induced muon tracks both in simulation and in data, and quantify its performance on exiting muon tracks in simulation. Read More

Atomic nuclei are complex strongly interacting systems and their exact theoretical description is a long-standing challenge. An approximate description of nuclei can be achieved by separating its short and long range structure. This separation of scales stands at the heart of the nuclear shell model and effective field theories that describe the long-range structure of the nucleus using a single-body mean field approximation. Read More

This article reviews our current understanding of how the internal quark structure of a nucleon bound in nuclei differs from that of a free nucleon. We focus on the interpretation of measurements of the EMC effect for valence quarks, a reduction in the Deep Inelastic Scattering (DIS) cross-section ratios for nuclei relative to deuterium, and its possible connection to nucleon-nucleon Short-Range Correlations (SRC) in nuclei. Our review and new analysis (involving the amplitudes of non-nucleonic configurations in the nucleus) of the available experimental and theoretical evidence shows that there is a phenomenological relation between the EMC effect and the effects of SRC that is not an accident. Read More

Background: The nuclear symmetry energy is a fundamental ingredient in determining the equation of state (EOS) of neutron stars (NS). Recent terrestrial experiments constrain both its value and slope at nuclear saturation density, however, its value at higher densities is unknown. Assuming a Free Fermi-gas (FFG) model for the kinetic symmetry energy, the high-density extrapolation depends on a single parameter, the density dependence of the potential symmetry energy. Read More

Neutrino oscillation measurements depend on a difference between the rate of neutrino-nucleus interactions at different neutrino energies or different distances from the source. Knowledge of the neutrino energy spectrum and neutrino-detector interactions are crucial for these experiments. Short range nucleon-nucleon correlations in nuclei (SRC) affect properties of nuclei. Read More

2016Feb
Affiliations: 1School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel, 2School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel, 3Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 4Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 5Jožef Stefan Institute, 1000 Ljubljana, Slovenia, 6Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 7Department of Physics, University of Zagreb, HR-10002 Zagreb, Croatia, 8Jožef Stefan Institute, 1000 Ljubljana, Slovenia, 9Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 10Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 11Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 12Department of Physics, University of Zagreb, HR-10002 Zagreb, Croatia, 13Rutgers, The State University of New Jersey, Piscataway, NJ 08855, USA, 14School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel, 15School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel, 16Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 17Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 18Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 19Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 20School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel, 21Jožef Stefan Institute, 1000 Ljubljana, Slovenia, 22University of South Carolina, Columbia, South Carolina 29208, USA, 23Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 24Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel, 25Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 26Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 27Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 28Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 29Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 30Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 31Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany, 32Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz, Germany

Possible differences between free and bound protons may be observed in the ratio of polarization-transfer components, $P'_x/P'_z$. We report the measurement of $P'_x/P'_z$, in the $^2\textrm{H}(\vec{e},e^{\prime}\vec{p})n$ reaction at low and high missing momenta. Observed increasing deviation of $P'_x/P'_z$ from that of a free proton as a function of the virtuality, similar to that observed in \hefour, indicates that the effect in nuclei is due to the virtuality of the knock-out proton and not due to the average nuclear density. Read More

The nuclear mass dependence of the number of short-range correlated (SRC) proton-proton (pp) and proton-neutron (pn) pairs in nuclei is a sensitive probe of the dynamics of short-range pairs in the ground state of atomic nuclei. This work presents an analysis of electroinduced single-proton and two-proton knockout measurements off 12C, 27Al, 56Fe, and 208Pb in kinematics dominated by scattering off SRC pairs. The nuclear mass dependence of the observed A(e,e'pp)/12C(e,e'pp) cross-section ratios and the extracted number of pp- and pn-SRC pairs are much softer than the mass dependence of the total number of possible pairs. Read More

We report the first measurement of the target single-spin asymmetry, $A_y$, in quasi-elastic scattering from the inclusive reaction $^3$He$^{\uparrow}(e,e^\prime)$ on a $^3$He gas target polarized normal to the lepton scattering plane. Assuming time-reversal invariance, this asymmetry is strictly zero for one-photon exchange. A non-zero $A_y$ can arise from the interference between the one- and two-photon exchange processes which is sensitive to the details of the sub-structure of the nucleon. Read More

New results are reported from a measurement of $\pi^0$ electroproduction near threshold using the $p(e,e^{\prime} p)\pi^0$ reaction. The experiment was designed to determine precisely the energy dependence of $s-$ and $p-$wave electromagnetic multipoles as a stringent test of the predictions of Chiral Perturbation Theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. Read More

2014Nov
Authors: O. Hen, M. Sargsian, L. B. Weinstein, E. Piasetzky, H. Hakobyan, D. W. Higinbotham, M. Braverman, W. K. Brooks, S. Gilad, K. P. Adhikari, J. Arrington, G. Asryan, H. Avakian, J. Ball, N. A. Baltzell, M. Battaglieri, A. Beck, S. May-Tal Beck, I. Bedlinskiy, W. Bertozzi, A. Biselli, V. D. Burkert, T. Cao, D. S. Carman, A. Celentano, S. Chandavar, L. Colaneri, P. L. Cole, V. Crede, A. DAngelo, R. De Vita, A. Deur, C. Djalali, D. Doughty, M. Dugger, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, G. Fedotov, S. Fegan, T. Forest, B. Garillon, M. Garcon, N. Gevorgyan, Y. Ghandilyan, G. P. Gilfoyle, F. X. Girod, J. T. Goetz, R. W. Gothe, K. A. Griffioen, M. Guidal, L. Guo, K. Hafidi, C. Hanretty, M. Hattawy, K. Hicks, M. Holtrop, C. E. Hyde, Y. Ilieva, D. G. Ireland, B. I. Ishkanov, E. L. Isupov, H. Jiang, H. S. Jo, K. Joo, D. Keller, M. Khandaker, A. Kim, W. Kim, F. J. Klein, S. Koirala, I. Korover, S. E. Kuhn, V. Kubarovsky, P. Lenisa, W. I. Levine, K. Livingston, M. Lowry, H. Y. Lu, I. J. D. MacGregor, N. Markov, M. Mayer, B. McKinnon, T. Mineeva, V. Mokeev, A. Movsisyan, C. Munoz Camacho, B. Mustapha, P. Nadel-Turonski, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, L. L. Pappalardo, R. Paremuzyan, K. Park, E. Pasyuk, W. Phelps, S. Pisano, O. Pogorelko, J. W. Price, S. Procureur, Y. Prok, D. Protopopescu, A. J. R. Puckett, D. Rimal, M. Ripani, B. G. Ritchie, A. Rizzo, G. Rosner, P. Rossi, P. Roy, F. Sabatie, D. Schott, R. A. Schumacher, Y. G. Sharabian, G. D. Smith, R. Shneor, D. Sokhan, S. S. Stepanyan, S. Stepanyan, P. Stoler, S. Strauch, V. Sytnik, M. Taiuti, S. Tkachenko, M. Ungaro, A. V. Vlassov, E. Voutier, D. Watts, N. K. Walford, X. Wei, M. H. Wood, S. A. Wood, N. Zachariou, L. Zana, Z. W. Zhao, X. Zheng, I. Zonta

The atomic nucleus is composed of two different kinds of fermions, protons and neutrons. If the protons and neutrons did not interact, the Pauli exclusion principle would force the majority fermions (usually neutrons) to have a higher average momentum. Our high-energy electron scattering measurements using 12C, 27Al, 56Fe and 208Pb targets show that, even in heavy neutron-rich nuclei, short-range interactions between the fermions form correlated high-momentum neutron-proton pairs. Read More

We present a precise measurement of double-polarization asymmetries in the $^3\vec{\mathrm{He}}(\vec{\mathrm{e}},\mathrm{e}'\mathrm{d})$ reaction. This particular process is a uniquely sensitive probe of hadron dynamics in $^3\mathrm{He}$ and the structure of the underlying electromagnetic currents. The measurements have been performed in and around quasi-elastic kinematics at $Q^2 = 0. Read More

The nuclear symmetry energy (E_sym(\roh)) is a vital ingredient of our understanding of many processes, from heavy-ion collisions to neutron stars structure. While the total nuclear symmetry energy at nuclear saturation density (\rho_0) is relatively well determined, its value at supranuclear densities is not. The latter can be better constrained by separately examining its kinetic and potential terms and their density dependencies. Read More

Background: The high momentum distribution of atoms in two spin-state ultra-cold atomic gases with strong short-range interactions between atoms with different spins, which can be described using Tan's contact, are dominated by short range pairs of different fermions and decreases as $k^{-4}$. In atomic nuclei the momentum distribution of nucleons above the Fermi momentum ($k>k_F \approx 250$ Mev/c) is also dominated by short rangecorrelated different-fermion (neutron-proton) pairs. Purpose: Compare high-momentum unlike-fermion momentum distributions in atomic and nuclear systems. Read More

2014May
Affiliations: 1Jefferson Lab Hall A Collaboration, 2Jefferson Lab Hall A Collaboration, 3Jefferson Lab Hall A Collaboration, 4Jefferson Lab Hall A Collaboration, 5Jefferson Lab Hall A Collaboration, 6Jefferson Lab Hall A Collaboration, 7Jefferson Lab Hall A Collaboration, 8Jefferson Lab Hall A Collaboration, 9Jefferson Lab Hall A Collaboration, 10Jefferson Lab Hall A Collaboration, 11Jefferson Lab Hall A Collaboration, 12Jefferson Lab Hall A Collaboration, 13Jefferson Lab Hall A Collaboration, 14Jefferson Lab Hall A Collaboration, 15Jefferson Lab Hall A Collaboration, 16Jefferson Lab Hall A Collaboration, 17Jefferson Lab Hall A Collaboration, 18Jefferson Lab Hall A Collaboration, 19Jefferson Lab Hall A Collaboration, 20Jefferson Lab Hall A Collaboration, 21Jefferson Lab Hall A Collaboration, 22Jefferson Lab Hall A Collaboration, 23Jefferson Lab Hall A Collaboration, 24Jefferson Lab Hall A Collaboration, 25Jefferson Lab Hall A Collaboration, 26Jefferson Lab Hall A Collaboration, 27Jefferson Lab Hall A Collaboration, 28Jefferson Lab Hall A Collaboration, 29Jefferson Lab Hall A Collaboration, 30Jefferson Lab Hall A Collaboration, 31Jefferson Lab Hall A Collaboration, 32Jefferson Lab Hall A Collaboration, 33Jefferson Lab Hall A Collaboration, 34Jefferson Lab Hall A Collaboration, 35Jefferson Lab Hall A Collaboration, 36Jefferson Lab Hall A Collaboration, 37Jefferson Lab Hall A Collaboration, 38Jefferson Lab Hall A Collaboration, 39Jefferson Lab Hall A Collaboration, 40Jefferson Lab Hall A Collaboration, 41Jefferson Lab Hall A Collaboration, 42Jefferson Lab Hall A Collaboration, 43Jefferson Lab Hall A Collaboration, 44Jefferson Lab Hall A Collaboration, 45Jefferson Lab Hall A Collaboration, 46Jefferson Lab Hall A Collaboration, 47Jefferson Lab Hall A Collaboration, 48Jefferson Lab Hall A Collaboration, 49Jefferson Lab Hall A Collaboration, 50Jefferson Lab Hall A Collaboration, 51Jefferson Lab Hall A Collaboration, 52Jefferson Lab Hall A Collaboration, 53Jefferson Lab Hall A Collaboration, 54Jefferson Lab Hall A Collaboration, 55Jefferson Lab Hall A Collaboration, 56Jefferson Lab Hall A Collaboration, 57Jefferson Lab Hall A Collaboration, 58Jefferson Lab Hall A Collaboration, 59Jefferson Lab Hall A Collaboration, 60Jefferson Lab Hall A Collaboration, 61Jefferson Lab Hall A Collaboration, 62Jefferson Lab Hall A Collaboration, 63Jefferson Lab Hall A Collaboration, 64Jefferson Lab Hall A Collaboration, 65Jefferson Lab Hall A Collaboration, 66Jefferson Lab Hall A Collaboration, 67Jefferson Lab Hall A Collaboration, 68Jefferson Lab Hall A Collaboration, 69Jefferson Lab Hall A Collaboration, 70Jefferson Lab Hall A Collaboration, 71Jefferson Lab Hall A Collaboration, 72Jefferson Lab Hall A Collaboration, 73Jefferson Lab Hall A Collaboration, 74Jefferson Lab Hall A Collaboration, 75Jefferson Lab Hall A Collaboration, 76Jefferson Lab Hall A Collaboration, 77Jefferson Lab Hall A Collaboration, 78Jefferson Lab Hall A Collaboration, 79Jefferson Lab Hall A Collaboration, 80Jefferson Lab Hall A Collaboration, 81Jefferson Lab Hall A Collaboration, 82Jefferson Lab Hall A Collaboration, 83Jefferson Lab Hall A Collaboration, 84Jefferson Lab Hall A Collaboration, 85Jefferson Lab Hall A Collaboration, 86Jefferson Lab Hall A Collaboration, 87Jefferson Lab Hall A Collaboration, 88Jefferson Lab Hall A Collaboration, 89Jefferson Lab Hall A Collaboration, 90Jefferson Lab Hall A Collaboration, 91Jefferson Lab Hall A Collaboration, 92Jefferson Lab Hall A Collaboration, 93Jefferson Lab Hall A Collaboration, 94Jefferson Lab Hall A Collaboration, 95Jefferson Lab Hall A Collaboration, 96Jefferson Lab Hall A Collaboration, 97Jefferson Lab Hall A Collaboration, 98Jefferson Lab Hall A Collaboration

In the absence of accurate data on the free two-body hyperon-nucleon interaction, the spectra of hypernuclei can provide information on the details of the effective hyperon-nucleon interaction. Electroproduction of the hypernucleus Lambda-9Li has been studied for the first time with sub-MeV energy resolution in Hall A at Jefferson Lab on a 9Be target. In order to increase the counting rate and to provide unambiguous kaon identification, two superconducting septum magnets and a Ring Imaging CHerenkov detector (RICH) were added to the Hall A standard equipment. Read More

Recent developments in understanding the influence of the nucleus on deep-inelastic structure functions, the EMC effect, are reviewed. A new data base which expresses ratios of structure functions in terms of the Bjorken variable $x_A=AQ^2/(2M_A q_0)$ is presented. Information about two-nucleon short-range correlations from experiments is also discussed and the remarkable linear relation between short-range correlations and teh EMC effect is reviewed. Read More

2013Mar
Authors: I. Pomerantz1, Y. Ilieva2, R. Gilman3, D. W. Higinbotham4, E. Piasetzky5, S. Strauch6, K. P. Adhikari7, M. Aghasyan8, K. Allada9, M. J. Amaryan10, S. Anefalos Pereira11, M. Anghinolfi12, H. Baghdasaryan13, J. Ball14, N. A. Baltzell15, M. Battaglieri16, V. Batourine17, A. Beck18, S. Beck19, I. Bedlinskiy20, B. L. Berman21, A. S. Biselli22, W. Boeglin23, J. Bono24, C. Bookwalter25, S. Boiarinov26, W. J. Briscoe27, W. K. Brooks28, N. Bubis29, V. Burkert30, A. Camsonne31, M. Canan32, D. S. Carman33, A. Celentano34, S. Chandavar35, G. Charles36, K. Chirapatpimol37, E. Cisbani38, P. L. Cole39, M. Contalbrigo40, V. Crede41, F. Cusanno42, A. D'Angelo43, A. Daniel44, N. Dashyan45, C. W. de Jager46, R. De Vita47, E. De Sanctis48, A. Deur49, C. Djalali50, G. E. Dodge51, D. Doughty52, R. Dupre53, C. Dutta54, H. Egiyan55, A. El Alaoui56, L. El Fassi57, P. Eugenio58, G. Fedotov59, S. Fegan60, J. A. Fleming61, A. Fradi62, F. Garibaldi63, O. Geagla64, N. Gevorgyan65, K. L. Giovanetti66, F. X. Girod67, J. Glister68, J. T. Goetz69, W. Gohn70, E. Golovatch71, R. W. Gothe72, K. A. Griffioen73, B. Guegan74, M. Guidal75, L. Guo76, K. Hafidi77, H. Hakobyan78, N. Harrison79, D. Heddle80, K. Hicks81, D. Ho82, M. Holtrop83, C. E. Hyde84, D. G. Ireland85, B. S. Ishkhanov86, E. L. Isupov87, X. Jiang88, H. S. Jo89, K. Joo90, A. T. Katramatou91, D. Keller92, M. Khandaker93, P. Khetarpal94, E. Khrosinkova95, A. Kim96, W. Kim97, F. J. Klein98, S. Koirala99, A. Kubarovsky100, V. Kubarovsky101, S. V. Kuleshov102, N. D. Kvaltine103, B. Lee104, J. J. LeRose105, S. Lewis106, R. Lindgren107, K. Livingston108, H. Y. Lu109, I. J. D. MacGregor110, Y. Mao111, D. Martinez112, M. Mayer113, E. McCullough114, B. McKinnon115, D. Meekins116, C. A. Meyer117, R. Michaels118, T. Mineeva119, M. Mirazita120, B. Moffit121, V. Mokeev122, R. A. Montgomery123, H. Moutarde124, E. Munevar125, C. Munoz Camacho126, P. Nadel-Turonski127, R. Nasseripour128, C. S. Nepali129, S. Niccolai130, G. Niculescu131, I. Niculescu132, M. Osipenko133, A. I. Ostrovidov134, L. L. Pappalardo135, R. Paremuzyan136, K. Park137, S. Park138, G. G. Petratos139, E. Phelps140, S. Pisano141, O. Pogorelko142, S. Pozdniakov143, S. Procureur144, D. Protopopescu145, A. J. R. Puckett146, X. Qian147, Y. Qiang148, G. Ricco149, D. Rimal150, M. Ripani151, B. G. Ritchie152, I. Rodriguez153, G. Ron154, G. Rosner155, P. Rossi156, F. Sabatie157, A. Saha158, M. S. Saini159, A. J. Sarty160, B. Sawatzky161, N. A. Saylor162, D. Schott163, E. Schulte164, R. A. Schumacher165, E. Seder166, H. Seraydaryan167, R. Shneor168, G. D. Smith169, D. Sokhan170, N. Sparveris171, S. S. Stepanyan172, S. Stepanyan173, P. Stoler174, R. Subedi175, V. Sulkosky176, M. Taiuti177, W. Tang178, C. E. Taylor179, S. Tkachenko180, M. Ungaro181, B. Vernarsky182, M. F. Vineyard183, H. Voskanyan184, E. Voutier185, N. K. Walford186, Y. Wang187, D. P. Watts188, L. B. Weinstein189, D. P. Weygand190, B. Wojtsekhowski191, M. H. Wood192, X. Yan193, H. Yao194, N. Zachariou195, X. Zhan196, J. Zhang197, Z. W. Zhao198, X. Zheng199, I. Zonta200
Affiliations: 1The CLAS and Hall-A Collaborations, 2The CLAS and Hall-A Collaborations, 3The CLAS and Hall-A Collaborations, 4The CLAS and Hall-A Collaborations, 5The CLAS and Hall-A Collaborations, 6The CLAS and Hall-A Collaborations, 7The CLAS and Hall-A Collaborations, 8The CLAS and Hall-A Collaborations, 9The CLAS and Hall-A Collaborations, 10The CLAS and Hall-A Collaborations, 11The CLAS and Hall-A Collaborations, 12The CLAS and Hall-A Collaborations, 13The CLAS and Hall-A Collaborations, 14The CLAS and Hall-A Collaborations, 15The CLAS and Hall-A Collaborations, 16The CLAS and Hall-A Collaborations, 17The CLAS and Hall-A Collaborations, 18The CLAS and Hall-A Collaborations, 19The CLAS and Hall-A Collaborations, 20The CLAS and Hall-A Collaborations, 21The CLAS and Hall-A Collaborations, 22The CLAS and Hall-A Collaborations, 23The CLAS and Hall-A Collaborations, 24The CLAS and Hall-A Collaborations, 25The CLAS and Hall-A Collaborations, 26The CLAS and Hall-A Collaborations, 27The 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We have measured cross sections for the gamma+3He->p+d reaction at photon energies of 0.4 - 1.4 GeV and a center-of-mass angle of 90 deg. Read More

The five-fold differential cross section for the 12C(e,e'p)11B reaction was determined over a missing momentum range of 200-400 MeV/c, in a kinematics regime with Bjorken x > 1 and Q2 = 2.0 (GeV/c)2. A comparison of the results and theoretical models and previous lower missing momentum data is shown. Read More

Nuclear transparency, Tp(A), is a measure of the average probability for a struck proton to escape the nucleus without significant re-interaction. Previously, nuclear transparencies were extructed for quasi-elastic A(e,e'p) knockout of protons with momentum below the Fermi momentum, where the spectral functions are well known. In this paper we extract a novel observable, the transparency ratio, Tp(A)/T_p(12C), for knockout of high-missing-momentum protons from the breakup of short range correlated pairs (2N-SRC) in Al, Fe and Pb nuclei relative to C. Read More

It is shown that polarization transfer measurements $(\vec{e},e'\vec{p})$ on a specific target nucleus can provide constraints on the ratio of the in-medium electric to magnetic form factor. Thereby one exploits the fact that proton knockout from single-particle levels exhibit a specific sensitivity to the effective nuclear density. It is shown that in $^{12}$C the effective nuclear density for $s$-shell knockout is about twice as high as for $p$-shell knockout. Read More

The deep inelastic scattering cross section for scattering from bound nucleons differs from that of free nucleons.This phenomena, first discovered 30 years ago, is known as the EMC effect and is still not fully understood. Recent analysis of world data showed that the strength of the EMC effect is linearly correlated with the relative amount of Two-Nucleon Short Range Correlated pairs (2N-SRC) in nuclei. Read More

Recently published measurements of the two nucleon short range correlation ($NN$-SRC) scaling factors, $a_2(A/d)$, strengthen the previously observed correlation between the magnitude of the EMC effect measured in electron deep inelastic scattering at $0.35\le x_B\le 0.7$ and the SRC scaling factor measured at $x_B \ge 1$. Read More

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. Read More

Recently the ratio of neutron to proton structure functions F_2n/F_2p was extracted from a phenomenological correlation between the strength of the nuclear EMC effect and inclusive electron-nucleus cross section ratios at x>1. Within conventional models of nuclear smearing, this "in-medium correction" (IMC) extraction constrains the size of nuclear effects in the deuteron structure functions, from which the neutron structure function F_2n is usually extracted. The IMC data determine the resulting proton d/u quark distribution ratio, extrapolated to x=1, to be 0. Read More

Due to the lack of a free neutron target the structure function of the neutron cannot be measured directly and is therefore extracted from deuteron and proton DIS data. Because the deuteron is a bound nuclear system, in order to extract the neutron structure function, one needs to apply model dependent theoretical corrections which dominate the uncertainty at the large xB region. We present here a correlation between the magnitude of the EMC effect and the amount of two nucleon Short Range Correlation (2N-SRC) pairs in nuclei. Read More

We present new data for the polarization observables of the final state proton in the $^{1}H(\vec{\gamma},\vec{p})\pi^{0}$ reaction. These data can be used to test predictions based on hadron helicity conservation (HHC) and perturbative QCD (pQCD). These data have both small statistical and systematic uncertainties, and were obtained with beam energies between 1. Read More

We present a search at Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling $\alpha'$ to electrons. Such a particle $A'$ can be produced in electron-nucleus fixed-target scattering and then decay to an $e^+e^-$ pair, producing a narrow resonance in the QED trident spectrum. Using APEX test run data, we searched in the mass range 175--250 MeV, found no evidence for an $A'\to e^+e^-$ reaction, and set an upper limit of $\alpha'/\alpha \simeq 10^{-6}$. Read More

We present an updated extraction of the proton electromagnetic form factor ratio, mu_p G_E/G_M, at low Q^2. The form factors are sensitive to the spatial distribution of the proton, and precise measurements can be used to constrain models of the proton. An improved selection of the elastic events and reduced background contributions yielded a small systematic reduction in the ratio mu_p G_E/G_M compared to the original analysis. Read More

2010Dec

Intensive theoretical and experimental efforts over the past decade have aimed at explaining the discrepancy between data for the proton electric to magnetic form factor ratio, $G_{E}/G_{M}$, obtained separately from cross section and polarization transfer measurements. One possible explanation for this difference is a two-photon-exchange (TPEX) contribution. In an effort to search for effects beyond the one-photon-exchange or Born approximation, we report measurements of polarization transfer observables in the elastic $H(\vec{e},e'\vec{p})$ reaction for three different beam energies at a fixed squared momentum transfer $Q^2 = 2. Read More

This paper shows quantitatively that the magnitude of the EMC effect measured in electron deep inelastic scattering (DIS) at intermediate $x_B$, $0.35\le x_B\le 0.7$, is linearly related to the Short Range Correlation (SRC) scaling factor obtained from electron inclusive scattering at $x_B\ge 1. Read More

2010Aug
Authors: S. Riordan, S. Abrahamyan, B. Craver, A. Kelleher, A. Kolarkar, J. Miller, G. D. Cates, N. Liyanage, B. Wojtsekhowski, A. Acha, K. Allada, B. Anderson, K. A. Aniol, J. R. M. Annand, J. Arrington, T. Averett, A. Beck, M. Bellis, W. Boeglin, H. Breuer, J. R. Calarco, A. Camsonne, J. P. Chen, E. Chudakov, L. Coman, B. Crowe, F. Cusanno, D. Day, P. Degtyarenko, P. A. M. Dolph, C. Dutta, C. Ferdi, C. Fernandez-Ramirez, R. Feuerbach, L. M. Fraile, G. Franklin, S. Frullani, S. Fuchs, F. Garibaldi, N. Gevorgyan, R. Gilman, A. Glamazdin, J. Gomez, K. Grimm, J. O. Hansen, J. L. Herraiz, D. W. Higinbotham, R. Holmes, T. Holmstrom, D. Howell, C. W. deJager, X. Jiang, M. K. Jones, J. Katich, L. J. Kaufman, M. Khandaker, J. J. Kelly, D. Kiselev, W. Korsch, J. LeRose, R. Lindgren, P. Markowitz, D. J. Margaziotis, S. May-Tal Beck, S. Mayilyan, K. McCormick, Z. E. Meziani, R. Michaels, B. Moffit, S. Nanda, V. Nelyubin, T. Ngo, D. M. Nikolenko, B. Norum, L. Pentchev, C. F. Perdrisat, E. Piasetzky, R. Pomatsalyuk, D. Protopopescu, A. J. R. Puckett, V. A. Punjabi, X. Qian, Y. Qiang, B. Quinn, I. Rachek, R. D. Ransome, P. E. Reimer, B. Reitz, J. Roche, G. Ron, O. Rondon, G. Rosner, A. Saha, M. Sargsian, B. Sawatzky, J. Segal, M. Shabestari, A. Shahinyan, Yu. Shestakov, J. Singh, S. Sirca, P. Souder, S. Stepanyan, V. Stibunov, V. Sulkosky, S. Tajima, W. A. Tobias, J. M. Udias, G. M. Urciuoli, B. Vlahovic, H. Voskanyan, K. Wang, F. R. Wesselmann, J. R. Vignote, S. A. Wood, J. Wright, H. Yao, X. Zhu

The electric form factor of the neutron was determined from studies of the reaction He3(e,e'n)pp in quasi-elastic kinematics in Hall A at Jefferson Lab. Longitudinally polarized electrons were scattered off a polarized target in which the nuclear polarization was oriented perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons that were registered in a large-solid-angle detector. Read More

2010May

Among the most fundamental observables of nucleon structure, electromagnetic form factors are a crucial benchmark for modern calculations describing the strong interaction dynamics of the nucleon's quark constituents; indeed, recent proton data have attracted intense theoretical interest. In this letter, we report new measurements of the proton electromagnetic form factor ratio using the recoil polarization method, at momentum transfers Q2=5.2, 6. Read More

Results of recent EMC effect measurements and nuclear scaling measurements have both been attributed to local nuclear density effects and not properties of the bulk nuclear system. This lead us to the phenomenological observation that the ratio of the slopes in the 0.3 < x_B < 0. Read More

High precision measurements of induced and transferred recoil proton polarization in d(polarized gamma, polarized p})n have been performed for photon energies of 277--357 MeV and theta_cm = 20 degrees -- 120 degrees. The measurements were motivated by a longstanding discrepancy between meson-baryon model calculations and data at higher energies. At the low energies of this experiment, theory continues to fail to reproduce the data, indicating that either something is missing in the calculations and/or there is a problem with the accuracy of the nucleon-nucleon potential being used. Read More

The protons and neutrons in a nucleus can form strongly correlated nucleon pairs. Scattering experiments, where a proton is knocked-out of the nucleus with high momentum transfer and high missing momentum, show that in 12C the neutron-proton pairs are nearly twenty times as prevalent as proton-proton pairs and, by inference, neutron-neutron pairs. This difference between the types of pairs is due to the nature of the strong force and has implications for understanding cold dense nuclear systems such as neutron stars. Read More

One of Jefferson Lab's original missions was to further our understanding of the short-distance structure of nuclei. In particular, to understand what happens when two or more nucleons within a nucleus have strongly overlapping wave-functions; a phenomena commonly referred to as short-range correlations. Herein, we review the results of the (e,e'), (e,e'p) and (e,e'pN) reactions that have been used at Jefferson Lab to probe this short-distance structure as well as provide an outlook for future experiments. Read More

The proton analyzing power in carbon has been measured for energies of 82 to 217 MeV and proton scattering angles of 5 to 41 degrees. The measurements were carried out using polarized protons from the elastic scattering H(pol. e, pol. Read More

Stationary target measurements of the nucleon form factors have been performed with high precision down to $Q^2$ of $\sim$ 0.01 GeV$^2$ for protons ($G_E^p$) and down to $\sim$ 0.1 GeV$^2$ for neutrons ($G_M^n$). Read More

We demonstrate that for small values of momentum transfer, Q^2, the in-medium change of the G_E/G_M form factor ratio for a bound neutron is dominated by the change in the electric charge radius and predict in a model independent manner that the in-medium ratio will increase relative to the free result. This effect will act to increase the predicted cross-section for the neutron recoil polarization transfer process 4He(e,e'n)3He. This is in contrast to medium modification effects on the proton G_E/G_M from factor ratio, which act to decrease the predicted cross-section for the 4He(e,e'p)3H reaction. Read More

An experimental study of the 16O(e,e'K^+)16N_Lambda reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e,e'K^+)Lambda,Sigma_0 exclusive reactions and a precise calibration of the energy scale. Read More

We study the ratio $R\equiv\mu G_E(Q^2)/G_M(Q^2)$ of the proton at very small values of $Q^2$. Radii commonly associated with these form factors are not moments of charge or magnetization densities. We show that the form factor $F_2$ is correctly interpretable as the two-dimensional Fourier transformation of a magnetization density. Read More

An experiment measuring electroproduction of hypernuclei has been performed in Hall A at Jefferson Lab on a $^{12}$C target. In order to increase counting rates and provide unambiguous kaon identification two superconducting septum magnets and a Ring Imaging CHerenkov detector (RICH) were added to the Hall A standard equipment. An unprecedented energy resolution of less than 700 keV FWHM has been achieved. Read More