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46 results on '"Keppel CE"'

1. Novel Measurement of the Neutron Magnetic Form Factor from A=3 Mirror Nuclei

Author

Santiesteban, SN, Li, S, Abrams, D, Alsalmi, S, Androic, D, Aniol, K, Arrington, J, Averett, T, Gayoso, C Ayerbe, Bane, J, Barcus, S, Barrow, J, Beck, A, Bellini, V, Bhatt, H, Bhetuwal, D, Biswas, D, Camsonne, A, Castellanos, J, Chen, J, Chen, J-P, Chrisman, D, Christy, ME, Clarke, C, Covrig, S, Cruz-Torres, R, Day, D, Dutta, D, Fuchey, E, Gal, C, Garibaldi, F, Gautam, TN, Gogami, T, Gomez, J, Guèye, P, Hague, TJ, Hansen, JO, Hauenstein, F, Henry, W, Higinbotham, DW, Holt, RJ, Hyde, C, Itabashi, K, Kaneta, M, Karki, A, Katramatou, AT, Keppel, CE, King, PM, Kurbany, L, Kutz, T, Lashley-Colthirst, N, Li, WB, Liu, H, Liyanage, N, Long, E, Lovato, A, Mammei, J, Markowitz, P, McClellan, RE, Meddi, F, Meekins, D, Michaels, R, Mihovilovič, M, Moyer, A, Nagao, S, Nguyen, D, Nycz, M, Olson, M, Ou, L, Owen, V, Palatchi, C, Pandey, B, Papadopoulou, A, Park, S, Petkovic, T, Premathilake, S, Punjabi, V, Ransome, RD, Reimer, PE, Reinhold, J, Riordan, S, Rocco, N, Rodriguez, VM, Schmidt, A, Schmookler, B, Segarra, EP, Shahinyan, A, Širca, S, Slifer, K, Solvignon, P, Su, T, Suleiman, R, Tang, L, Tian, Y, Tireman, W, Tortorici, F, Toyama, Y, Uehara, K, Urciuoli, GM, and Votaw, D

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Jefferson Lab Hall A Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

The electromagnetic form factors of the proton and neutron encode information on the spatial structure of their charge and magnetization distributions. While measurements of the proton are relatively straightforward, the lack of a free neutron target makes measurements of the neutron's electromagnetic structure more challenging and more sensitive to experimental or model-dependent uncertainties. Various experiments have attempted to extract the neutron form factors from scattering from the neutron in deuterium, with different techniques providing different, and sometimes large, systematic uncertainties. We present results from a novel measurement of the neutron magnetic form factor using quasielastic scattering from the mirror nuclei ^{3}H and ^{3}He, where the nuclear effects are larger than for deuterium but expected to largely cancel in the cross-section ratios. We extracted values of the neutron magnetic form factor for low-to-modest momentum transfer, 0.6

Published
2024

2. Revealing the short-range structure of the mirror nuclei 3H and 3He

Author

Li, S, Cruz-Torres, R, Santiesteban, N, Ye, ZH, Abrams, D, Alsalmi, S, Androic, D, Aniol, K, Arrington, J, Averett, T, Gayoso, C Ayerbe, Bane, J, Barcus, S, Barrow, J, Beck, A, Bellini, V, Bhatt, H, Bhetuwal, D, Biswas, D, Bulumulla, D, Camsonne, A, Castellanos, J, Chen, J, Chen, J-P, Chrisman, D, Christy, ME, Clarke, C, Covrig, S, Craycraft, K, Day, D, Dutta, D, Fuchey, E, Gal, C, Garibaldi, F, Gautam, TN, Gogami, T, Gomez, J, Guèye, P, Habarakada, A, Hague, TJ, Hansen, JO, Hauenstein, F, Henry, W, Higinbotham, DW, Holt, RJ, Hyde, C, Itabashi, T, Kaneta, M, Karki, A, Katramatou, AT, Keppel, CE, Khachatryan, M, Khachatryan, V, King, PM, Korover, I, Kurbany, L, Kutz, T, Lashley-Colthirst, N, Li, WB, Liu, H, Liyanage, N, Long, E, Mammei, J, Markowitz, P, McClellan, RE, Meddi, F, Meekins, D, Beck, S Mey-Tal, Michaels, R, Mihovilovič, M, Moyer, A, Nagao, S, Nelyubin, V, Nguyen, D, Nycz, M, Olson, M, Ou, L, Owen, V, Palatchi, C, Pandey, B, Papadopoulou, A, Park, S, Paul, S, Petkovic, T, Pomatsalyuk, R, Premathilake, S, Punjabi, V, Ransome, RD, Reimer, PE, Reinhold, J, Riordan, S, Roche, J, Rodriguez, VM, Schmidt, A, Schmookler, B, Segarra, EP, Shahinyan, A, Slifer, K, Solvignon, P, and Širca, S

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, General Science & Technology
Abstract

When protons and neutrons (nucleons) are bound into atomic nuclei, they are close enough to feel significant attraction, or repulsion, from the strong, short-distance part of the nucleon-nucleon interaction. These strong interactions lead to hard collisions between nucleons, generating pairs of highly energetic nucleons referred to as short-range correlations (SRCs). SRCs are an important but relatively poorly understood part of nuclear structure1-3, and mapping out the strength and the isospin structure (neutron-proton (np) versus proton-proton (pp) pairs) of these virtual excitations is thus critical input for modelling a range of nuclear, particle and astrophysics measurements3-5. Two-nucleon knockout or 'triple coincidence' reactions have been used to measure the relative contribution of np-SRCs and pp-SRCs by knocking out a proton from the SRC and detecting its partner nucleon (proton or neutron). These measurements6-8 have shown that SRCs are almost exclusively np pairs, but they had limited statistics and required large model-dependent final-state interaction corrections. Here we report on measurements using inclusive scattering from the mirror nuclei hydrogen-3 and helium-3 to extract the np/pp ratio of SRCs in systems with a mass number of three. We obtain a measure of the np/pp SRC ratio that is an order of magnitude more precise than previous experiments, and find a marked deviation from the near-total np dominance observed in heavy nuclei. This result implies an unexpected structure in the high-momentum wavefunction for hydrogen-3 and helium-3. Understanding these results will improve our understanding of the short-range part of the nucleon-nucleon interaction.

Published
2022

3. Measurement of R=σL/σT and the separated longitudinal and transverse structure functions in the nucleon-resonance region

Author

Liang, Y, Tvaskis, V, Christy, ME, Ahmidouch, A, Armstrong, CS, Arrington, J, Asaturyan, R, Avery, S, Baker, OK, Beck, DH, Blok, HP, Bochna, CW, Boeglin, W, Bosted, P, Bouwhuis, M, Breuer, H, Brown, DS, Bruell, A, Carlini, RD, Cha, J, Chant, NS, Cochran, A, Cole, L, Danagoulian, S, Day, DB, Dunne, J, Dutta, D, Ent, R, Fenker, HC, Fox, B, Gan, L, Gao, H, Garrow, K, Gaskell, D, Gasparian, A, Geesaman, DF, Gilman, R, Guèye, PLJ, Harvey, M, Holt, RJ, Jiang, X, Jones, M, Keppel, CE, Kinney, E, Lorenzon, W, Lung, A, Mack, DJ, Markowitz, P, Martin, JW, McIlhany, K, McKee, D, Meekins, D, Miller, MA, Milner, RG, Mitchell, JH, Mkrtchyan, H, Mueller, BA, Nathan, A, Niculescu, G, Niculescu, I, O'Neill, TG, Papavassiliou, V, Pate, SF, Piercey, RB, Potterveld, D, Ransome, RD, Reinhold, J, Rollinde, E, Rondon, O, Roos, P, Sarty, AJ, Sawafta, R, Schulte, EC, Segbefia, E, Smith, C, Stepanyan, S, Strauch, S, Tadevosyan, V, Tang, L, Tieulent, R, Uzzle, A, Vulcan, WF, Wood, SA, Xiong, F, Yuan, L, Zeier, M, Zihlmann, B, and Ziskin, V

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Nuclear and plasma physics
Abstract

We report on a detailed study of longitudinal strength in the nucleon resonance region, presenting new results from inclusive electron-proton cross sections measured at Jefferson Lab Hall C in the four-momentum transfer range 0.2

Published
2022

4. Measurement of the EMC effect in light and heavy nuclei

Author

Arrington, J, Bane, J, Daniel, A, Fomin, N, Gaskell, D, Seely, J, Asaturyan, R, Benmokhtar, F, Boeglin, W, Bosted, P, Bukhari, MHS, Christy, ME, Connell, S, Dalton, MM, Day, D, Dunne, J, Dutta, D, Fassi, L El, Ent, R, Fenker, H, Gao, H, Holt, RJ, Horn, T, Hungerford, E, Jones, MK, Jourdan, J, Kalantarians, N, Keppel, CE, Kiselev, D, Lung, AF, Malace, S, Meekins, DG, Mertens, T, Mkrtchyan, H, Niculescu, G, Niculescu, I, Potterveld, DH, Perdrisat, C, Punjabi, V, Qian, X, Reimer, PE, Roche, J, Rodriguez, VM, Rondon, O, Schulte, E, Slifer, K, Smith, GR, Solvignon, P, Tadevosyan, V, Tang, L, Testa, G, Trojer, R, Tvaskis, V, Wesselmann, FR, Wood, SA, Yuan, L, and Zheng, X

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Nuclear and plasma physics
Abstract

Inclusive electron scattering from nuclear targets has been measured to extract the nuclear dependence of the inelastic cross section (σA) in Hall C at the Thomas Jefferson National Accelerator facility. Results are presented for H2, He3, He4, B9, C12, Cu63, and Au197 at an incident electron beam energy of 5.77 GeV for a range of momentum transfer from Q2 = 2 to 7 (GeV/c)2. These data improve the precision of the existing measurements of the EMC effect in the nuclear targets at large x and allow for more detailed examinations of the A dependence of the EMC effect.

Published
2021

5. Exclusive π+ electroproduction off the proton from low to high -t

Author

Basnet, S, Huber, GM, Li, WB, Blok, HP, Gaskell, D, Horn, T, Aniol, K, Arrington, J, Beise, EJ, Boeglin, W, Brash, EJ, Breuer, H, Chang, CC, Christy, ME, Ent, R, Gibson, E, Holt, RJ, Jin, S, Jones, MK, Keppel, CE, Kim, W, King, PM, Kovaltchouk, V, Liu, J, Lolos, GJ, MacK, DJ, Margaziotis, DJ, Markowitz, P, Matsumura, A, Meekins, D, Miyoshi, T, Mkrtchyan, H, Niculescu, I, Okayasu, Y, Pentchev, L, Perdrisat, C, Potterveld, D, Punjabi, V, Reimer, P, Reinhold, J, Roche, J, Sarty, A, Smith, GR, Tadevosyan, V, Tang, LG, Tvaskis, V, Volmer, J, Vulcan, W, Warren, G, Wood, SA, Xu, C, and Zheng, X

Subjects
nucl-ex, hep-ex
Abstract

Background: Measurements of exclusive meson production are a useful tool in the study of hadronic structure. In particular, one can discern the relevant degrees of freedom at different distance scales through these studies. Purpose: To study the transition between nonperturbative and perturbative quantum chromodynamics as the square of four-momentum transfer to the struck proton, -t, is increased. Method: Cross sections for the H1(e,e′π+)n reaction were measured over the -t range of 0.272 to 2.127 GeV2 with limited azimuthal coverage at fixed beam energy of 4.709 GeV, Q2 of 2.4 GeV2, and W of 2.0 GeV at the Thomas Jefferson National Accelerator Facility (JLab) Hall C. Results: The -t dependence of the measured π+ electroproduction cross section generally agrees with prior data from JLab Halls B and C. The data are consistent with a Regge amplitude-based theoretical model but show poor agreement with a generalized parton distribution-based model. Conclusion: The agreement of cross sections with prior data implies small contribution from the interference terms, and the confirmation of the change in t slopes between the low- and high - t regions previously observed in photoproduction indicates the changing nature of the electroproduction reaction in our kinematic regime.

Published
2019

6. Exclusive π+ electroproduction off the proton from low to high −t

Author

Basnet, S, Huber, GM, Li, WB, Blok, HP, Gaskell, D, Horn, T, Aniol, K, Arrington, J, Beise, EJ, Boeglin, W, Brash, EJ, Breuer, H, Chang, CC, Christy, ME, Ent, R, Gibson, E, Holt, RJ, Jin, S, Jones, MK, Keppel, CE, Kim, W, King, PM, Kovaltchouk, V, Liu, J, Lolos, GJ, Mack, DJ, Margaziotis, DJ, Markowitz, P, Matsumura, A, Meekins, D, Miyoshi, T, Mkrtchyan, H, Niculescu, I, Okayasu, Y, Pentchev, L, Perdrisat, C, Potterveld, D, Punjabi, V, Reimer, P, Reinhold, J, Roche, J, Sarty, A, Smith, GR, Tadevosyan, V, Tang, LG, Tvaskis, V, Volmer, J, Vulcan, W, Warren, G, Wood, SA, Xu, C, and Zheng, X

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, nucl-ex, hep-ex, Nuclear and plasma physics
Abstract

Background: Measurements of exclusive meson production are a useful tool in the study of hadronic structure. In particular, one can discern the relevant degrees of freedom at different distance scales through these studies. Purpose: To study the transition between nonperturbative and perturbative quantum chromodynamics as the square of four-momentum transfer to the struck proton, -t, is increased. Method: Cross sections for the H1(e,e′π+)n reaction were measured over the -t range of 0.272 to 2.127 GeV2 with limited azimuthal coverage at fixed beam energy of 4.709 GeV, Q2 of 2.4 GeV2, and W of 2.0 GeV at the Thomas Jefferson National Accelerator Facility (JLab) Hall C. Results: The -t dependence of the measured π+ electroproduction cross section generally agrees with prior data from JLab Halls B and C. The data are consistent with a Regge amplitude-based theoretical model but show poor agreement with a generalized parton distribution-based model. Conclusion: The agreement of cross sections with prior data implies small contribution from the interference terms, and the confirmation of the change in t slopes between the low- and high - t regions previously observed in photoproduction indicates the changing nature of the electroproduction reaction in our kinematic regime.

Published
2019

7. Unique Access to u-Channel Physics: Exclusive Backward-Angle Omega Meson Electroproduction

Author

Li, WB, Huber, GM, Blok, HP, Gaskell, D, Horn, T, Semenov-Tian-Shansky, K, Pire, B, Szymanowski, L, Laget, J-M, Aniol, K, Arrington, J, Beise, EJ, Boeglin, W, Brash, EJ, Breuer, H, Chang, CC, Christy, ME, Ent, R, Gibson, EF, Holt, RJ, Jin, S, Jones, MK, Keppel, CE, Kim, W, King, PM, Kovaltchouk, V, Liu, J, Lolos, GJ, Mack, DJ, Margaziotis, DJ, Markowitz, P, Matsumura, A, Meekins, D, Miyoshi, T, Mkrtchyan, H, Niculescu, I, Okayasu, Y, Pentchev, L, Perdrisat, C, Potterveld, D, Punjabi, V, Reimer, PE, Reinhold, J, Roche, J, Roos, PG, Sarty, A, Smith, GR, Tadevosyan, V, Tang, LG, Tvaskis, V, Volmer, J, Vulcan, W, Warren, G, Wood, SA, Xu, C, and Zheng, X

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Jefferson Lab Fπ Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

Backward-angle meson electroproduction above the resonance region, which was previously ignored, is anticipated to offer unique access to the three quark plus sea component of the nucleon wave function. In this Letter, we present the first complete separation of the four electromagnetic structure functions above the resonance region in exclusive ω electroproduction off the proton, ep→e^{'}pω, at central Q^{2} values of 1.60, 2.45  GeV^{2}, at W=2.21  GeV. The results of our pioneering -u≈-u_{min} study demonstrate the existence of a unanticipated backward-angle cross section peak and the feasibility of full L/T/LT/TT separations in this never explored kinematic territory. At Q^{2}=2.45  GeV^{2}, the observed dominance of σ_{T} over σ_{L}, is qualitatively consistent with the collinear QCD description in the near-backward regime, in which the scattering amplitude factorizes into a hard subprocess amplitude and baryon to meson transition distribution amplitudes: universal nonperturbative objects only accessible through backward-angle kinematics.

Published
2019

8. Exposing novel quark and gluon effects in nuclei

Author

Cloët, IC, Dupré, R, Riordan, S, Armstrong, W, Arrington, J, Cosyn, W, Fomin, N, Freese, A, Fucini, S, Gaskell, D, Keppel, CE, Miller, GA, Pace, E, Platchkov, S, Reimer, PE, Scopetta, S, Thomas, AW, and Zurita, P

Subjects
EMC effect, nuclear modification, deep inelastic scattering, short ranged correlation, medium modification, tagged scattering, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Abstract

The fundamental theory of the strong interaction-quantum chromodynamics (QCD) - provides the foundational framework with which to describe and understand the key properties of atomic nuclei. A deep understanding of the explicit role of quarks and gluons in nuclei remains elusive however, as these effects have thus far been well-disguised by confinement effects in QCD which are encapsulated by a successful description in terms of effective hadronic degrees of freedom. The observation of the EMC effect has provided an enduring indication for explicit QCD effects in nuclei, and points to the medium modification of the bound protons and neutrons in the nuclear medium. Understanding the EMC effect is a major challenge for modern nuclear physics, and several key questions remain, such as understanding its flavor, spin, and momentum dependence. This manuscript provides a contemporary snapshot of our understanding of the role of QCD in nuclei and outlines possible pathways in experiment and theory that will help deepen our understanding of nuclei in the context of QCD.

Published
2019

9. Measurements of Nonsinglet Moments of the Nucleon Structure Functions and Comparison to Predictions from Lattice QCD for Q2=4 GeV2

Author

Albayrak, I, Mamyan, V, Christy, ME, Ahmidouch, A, Arrington, J, Asaturyan, A, Bodek, A, Bosted, P, Bradford, R, Brash, E, Bruell, A, Butuceanu, C, Coleman, SJ, Commisso, M, Connell, SH, Dalton, MM, Danagoulian, S, Daniel, A, Day, DB, Dhamija, S, Dunne, J, Dutta, D, Ent, R, Gaskell, D, Gasparian, A, Gran, R, Horn, T, Huang, Liting, Huber, GM, Jayalath, C, Johnson, M, Jones, MK, Kalantarians, N, Liyanage, A, Keppel, CE, Kinney, E, Li, Y, Malace, S, Manly, S, Markowitz, P, Maxwell, J, Mbianda, NN, McFarland, KS, Meziane, M, Meziani, ZE, Mills, GB, Mkrtchyan, H, Mkrtchyan, A, Mulholland, J, Nelson, J, Niculescu, G, Niculescu, I, Pentchev, L, Puckett, A, Punjabi, V, Qattan, IA, Reimer, PE, Reinhold, J, Rodriguez, VM, Rondon-Aramayo, O, Sakuda, M, Sakumoto, WK, Segbefia, E, Seva, T, Sick, I, Slifer, K, Smith, GR, Steinman, J, Solvignon, P, Tadevosyan, V, Tajima, S, Tvaskis, V, Vulcan, WF, Walton, T, Wesselmann, FR, Wood, SA, and Ye, Zhihong

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, E06-009 Collaboration, nucl-ex, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

We present extractions of the nucleon nonsinglet moments utilizing new precision data on the deuteron F_{2} structure function at large Bjorken-x determined via the Rosenbluth separation technique at Jefferson Lab Experimental Hall C. These new data are combined with a complementary set of data on the proton previously measured in Hall C at similar kinematics and world datasets on the proton and deuteron at lower x measured at SLAC and CERN. The new Jefferson Lab data provide coverage of the upper third of the x range, crucial for precision determination of the higher moments. In contrast to previous extractions, these moments have been corrected for nuclear effects in the deuteron using a new global fit to the deuteron and proton data. The obtained experimental moments represent an order of magnitude improvement in precision over previous extractions using high x data. Moreover, recent exciting developments in lattice QCD calculations provide a first ever comparison of these new experimental results with calculations of moments carried out at the physical pion mass, as well as a new approach that first calculates the quark distributions directly before determining moments.

Published
2019

10. Measurements of the separated longitudinal structure function FL from hydrogen and deuterium targets at low Q2

Author

Tvaskis, V, Tvaskis, A, Niculescu, I, Abbott, D, Adams, GS, Afanasev, A, Ahmidouch, A, Angelescu, T, Arrington, J, Asaturyan, R, Avery, S, Baker, OK, Benmouna, N, Berman, BL, Biselli, A, Blok, HP, Boeglin, WU, Bosted, PE, Brash, E, Breuer, H, Chang, G, Chant, N, Christy, ME, Connell, SH, Dalton, MM, Danagoulian, S, Day, D, Dodario, T, Dunne, JA, Dutta, D, El Khayari, N, Ent, R, Fenker, HC, Frolov, VV, Gaskell, D, Garrow, K, Gilman, R, Gueye, P, Hafidi, K, Hinton, W, Holt, RJ, Horn, T, Huber, GM, Jackson, H, Jiang, X, Jones, MK, Joo, K, Kelly, JJ, Keppel, CE, Kuhn, J, Kinney, E, Klein, A, Kubarovsky, V, Liang, Y, Lolos, G, Lung, A, Mack, D, Malace, S, Markowitz, P, Mbianda, G, McGrath, E, McKee, D, Meekins, DG, Mkrtchyan, H, Napolitano, J, Navasardyan, T, Niculescu, G, Nozar, M, Ostapenko, T, Papandreou, Z, Potterveld, D, Reimer, PE, Reinhold, J, Roche, J, Rock, SE, Schulte, E, Segbefia, E, Smith, C, Smith, GR, Stoler, P, Tadevosyan, V, Tang, L, Telfeyan, J, Todor, L, Ungaro, M, Uzzle, A, Vidakovic, S, Villano, A, Vulcan, WF, Warren, G, Wesselmann, F, Wojtsekhowski, B, Wood, SA, Yan, C, and Zihlmann, B

Abstract

Structure functions, as measured in lepton-nucleon scattering, have proven to be very useful in studying the partonic dynamics within the nucleon. However, it is experimentally difficult to separately determine the longitudinal and transverse structure functions, and consequently there are substantially less data available in particular for the longitudinal structure function. Here, we present separated structure functions for hydrogen and deuterium at low four-momentum transfer squared, Q2

Published
2018

11. Separated kaon electroproduction cross section and the kaon form factor from 6 GeV JLab data

Author

Carmignotto, M, Ali, S, Aniol, K, Arrington, J, Barrett, B, Beise, EJ, Blok, HP, Boeglin, W, Brash, EJ, Breuer, H, Chang, CC, Christy, ME, Dittmann, A, Ent, R, Fenker, H, Gaskell, D, Gibson, E, Holt, RJ, Horn, T, Huber, GM, Jin, S, Jones, MK, Keppel, CE, Kim, W, King, PM, Kovaltchouk, V, Liu, J, Lolos, GJ, MacK, DJ, Margaziotis, DJ, Markowitz, P, Matsumura, A, Meekins, D, Miyoshi, T, Mkrtchyan, H, Niculescu, G, Niculescu, I, Okayasu, Y, Pegg, IL, Pentchev, L, Perdrisat, C, Potterveld, D, Punjabi, V, Reimer, PE, Reinhold, J, Roche, J, Sarty, A, Smith, GR, Tadevosyan, V, Tang, LG, Trotta, R, Tvaskis, V, Vargas, A, Vidakovic, S, Volmer, J, Vulcan, W, Warren, G, Wood, SA, Xu, C, and Zheng, X

Subjects
nucl-ex
Abstract

The H1(e,e′K+)Λ reaction was studied as a function of the Mandelstam variable -t using data from the E01-004 (FPI-2) and E93-018 experiments that were carried out in Hall C at the 6 GeV Jefferson Laboratory. The cross section was fully separated into longitudinal and transverse components, and two interference terms at four-momentum transfers Q2 of 1.00, 1.36, and 2.07GeV2. The kaon form factor was extracted from the longitudinal cross section using the Regge model by Vanderhaeghen et al. [Phys. Rev. C 57, 1454 (1998)PRVCAN0556-281310.1103/PhysRevC.57.1454]. The results establish the method, previously used successfully for pion analyses, for extracting the kaon form factor. Data from 12 GeV Jefferson Laboratory experiments are expected to have sufficient precision to distinguish between theoretical predictions, for example, recent perturbative QCD calculations with modern parton distribution amplitudes. The leading-twist behavior for light mesons is predicted to set in for values of Q2 between 5 and 10GeV2, which makes data in the few-GeV regime particularly interesting. The Q2 dependence at fixed x and -t of the longitudinal cross section that we extracted seems consistent with the QCD factorization prediction within the experimental uncertainty.

Published
2018

12. MINERvA : High statistics neutrino scattering using a fine-grained detector

Author

Naples, D Blazey, G Bodek, A Boehnlein, D Boyd, S and Brooks, WK Bruells, A Budd, H Burnstein, R Casper, D and Chakravorty, A Christy, ME Chvojka, J Cummings, MAC and Drakoulakos, D Dunmore, J Ents, R Gallagher, H Gaskells, D Gilman, R Glasshausser, C Harris, DA Hinton, W and Jiang, X Kafka, T Kamaev, O Keppel, CE Kostin, M and Kulagin, S Kumbartzki, G McCormick, K McFarland, K and Manly, S Mann, WA Melnitchouks, W Morfin, JG Nelson, JK and Niculescu, G Niculescu, I Oliver, W Paolone, V Park, J Paschos, E Ransome, R Regis, C Rykalin, V and Sakumoto, W Shanahan, P Solomey, N Spentzouris, P and Stamoulis, P Tzanakos, G Woods, S Ziemer, B Zois, M and MINERvA Collaboration

Subjects
Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Phenomenology, Physics::Accelerator Physics, High Energy Physics::Experiment
Abstract

The MINERvA experiment at Fermilab will use a fully-active scintillator based fine grained neutrino detector and the high rate NuMI neutrino beam. MINERvA will measure low energy neutrino interaction properties and cross sections to a new level of precision. These measurements will be critical input to present and future accelerator-based neutrino oscillation experiments in this energy range.

Published
2005

13. Revealing the short-range structure of the mirror nuclei 3 H and 3 He.

Author

Li S, Cruz-Torres R, Santiesteban N, Ye ZH, Abrams D, Alsalmi S, Androic D, Aniol K, Arrington J, Averett T, Gayoso CA, Bane J, Barcus S, Barrow J, Beck A, Bellini V, Bhatt H, Bhetuwal D, Biswas D, Bulumulla D, Camsonne A, Castellanos J, Chen J, Chen JP, Chrisman D, Christy ME, Clarke C, Covrig S, Craycraft K, Day D, Dutta D, Fuchey E, Gal C, Garibaldi F, Gautam TN, Gogami T, Gomez J, Guèye P, Habarakada A, Hague TJ, Hansen JO, Hauenstein F, Henry W, Higinbotham DW, Holt RJ, Hyde C, Itabashi T, Kaneta M, Karki A, Katramatou AT, Keppel CE, Khachatryan M, Khachatryan V, King PM, Korover I, Kurbany L, Kutz T, Lashley-Colthirst N, Li WB, Liu H, Liyanage N, Long E, Mammei J, Markowitz P, McClellan RE, Meddi F, Meekins D, Beck SM, Michaels R, Mihovilovič M, Moyer A, Nagao S, Nelyubin V, Nguyen D, Nycz M, Olson M, Ou L, Owen V, Palatchi C, Pandey B, Papadopoulou A, Park S, Paul S, Petkovic T, Pomatsalyuk R, Premathilake S, Punjabi V, Ransome RD, Reimer PE, Reinhold J, Riordan S, Roche J, Rodriguez VM, Schmidt A, Schmookler B, Segarra EP, Shahinyan A, Slifer K, Solvignon P, Širca S, Su T, Suleiman R, Szumila-Vance H, Tang L, Tian Y, Tireman W, Tortorici F, Toyama Y, Uehara K, Urciuoli GM, Votaw D, Williamson J, Wojtsekhowski B, Wood S, Zhang J, and Zheng X

Abstract

When protons and neutrons (nucleons) are bound into atomic nuclei, they are close enough to feel significant attraction, or repulsion, from the strong, short-distance part of the nucleon-nucleon interaction. These strong interactions lead to hard collisions between nucleons, generating pairs of highly energetic nucleons referred to as short-range correlations (SRCs). SRCs are an important but relatively poorly understood part of nuclear structure 1-3 , and mapping out the strength and the isospin structure (neutron-proton (np) versus proton-proton (pp) pairs) of these virtual excitations is thus critical input for modelling a range of nuclear, particle and astrophysics measurements 3-5 . Two-nucleon knockout or 'triple coincidence' reactions have been used to measure the relative contribution of np-SRCs and pp-SRCs by knocking out a proton from the SRC and detecting its partner nucleon (proton or neutron). These measurements 6-8 have shown that SRCs are almost exclusively np pairs, but they had limited statistics and required large model-dependent final-state interaction corrections. Here we report on measurements using inclusive scattering from the mirror nuclei hydrogen-3 and helium-3 to extract the np/pp ratio of SRCs in systems with a mass number of three. We obtain a measure of the np/pp SRC ratio that is an order of magnitude more precise than previous experiments, and find a marked deviation from the near-total np dominance observed in heavy nuclei. This result implies an unexpected structure in the high-momentum wavefunction for hydrogen-3 and helium-3. Understanding these results will improve our understanding of the short-range part of the nucleon-nucleon interaction., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Published
2022
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14. New Measurements of the Beam-Normal Single Spin Asymmetry in Elastic Electron Scattering over a Range of Spin-0 Nuclei.

Author

Adhikari D, Albataineh H, Androic D, Aniol K, Armstrong DS, Averett T, Ayerbe Gayoso C, Barcus S, Bellini V, Beminiwattha RS, Benesch JF, Bhatt H, Bhatta Pathak D, Bhetuwal D, Blaikie B, Boyd J, Campagna Q, Camsonne A, Cates GD, Chen Y, Clarke C, Cornejo JC, Covrig Dusa S, Dalton MM, Datta P, Deshpande A, Dutta D, Feldman C, Fuchey E, Gal C, Gaskell D, Gautam T, Gericke M, Ghosh C, Halilovic I, Hansen JO, Hauenstein F, Henry W, Horowitz CJ, Jantzi C, Jian S, Johnston S, Jones DC, Karki B, Kakkar S, Katugampola S, Keppel CE, King PM, King DE, Knauss M, Kumar KS, Kutz T, Lashley-Colthirst N, Leverick G, Liu H, Liyange N, Malace S, Mammei J, Mammei R, McCaughan M, McNulty D, Meekins D, Metts C, Michaels R, Mihovilovic M, Mondal MM, Napolitano J, Nikolaev D, Rashad MNH, Owen V, Palatchi C, Pan J, Pandey B, Park S, Paschke KD, Petrusky M, Pitt ML, Premathilake S, Puckett AJR, Quinn B, Radloff R, Rahman S, Rathnayake A, Reed BT, Reimer PE, Richards R, Riordan S, Roblin Y, Seeds S, Shahinyan A, Souder PA, Tang L, Thiel M, Tian Y, Urciuoli GM, Wertz EW, Wojtsekhowski B, Xiong W, Yale B, Ye T, Zec A, Zhang W, Zhang J, and Zheng X

Abstract

We report precision determinations of the beam-normal single spin asymmetries (A_{n}) in the elastic scattering of 0.95 and 2.18 GeV electrons off ^{12}C, ^{40}Ca, ^{48}Ca, and ^{208}Pb at very forward angles where the most detailed theoretical calculations have been performed. The first measurements of A_{n} for ^{40}Ca and ^{48}Ca are found to be similar to that of ^{12}C, consistent with expectations and thus demonstrating the validity of theoretical calculations for nuclei with Z≤20. We also report A_{n} for ^{208}Pb at two new momentum transfers (Q^{2}) extending the previous measurement. Our new data confirm the surprising result previously reported, with all three data points showing significant disagreement with the results from the Z≤20 nuclei. These data confirm our basic understanding of the underlying dynamics that govern A_{n} for nuclei containing ≲50 nucleons, but point to the need for further investigation to understand the unusual A_{n} behavior discovered for scattering off ^{208}Pb.

Published
2022
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15. Isovector EMC Effect from Global QCD Analysis with MARATHON Data.

Author

Cocuzza C, Keppel CE, Liu H, Melnitchouk W, Metz A, Sato N, and Thomas AW

Abstract

We report the results of a Monte Carlo global QCD analysis of unpolarized parton distribution functions (PDFs), including for the first time constraints from ratios of ^{3}He to ^{3}H structure functions recently obtained by the MARATHON experiment at Jefferson Lab. Our simultaneous analysis of nucleon PDFs and nuclear effects in A=2 and A=3 nuclei reveals the first indication for an isovector nuclear EMC effect in light nuclei. We find that while the MARATHON data yield relatively weak constraints on the F_{2}^{n}/F_{2}^{p} neutron to proton structure function ratio and on the d/u PDF ratio, they suggest an enhanced nuclear effect on the d-quark PDF in the bound proton, questioning the assumptions commonly made in nuclear PDF analyses.

Published
2021
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16. Probing the Deuteron at Very Large Internal Momenta.

Author

Yero C, Abrams D, Ahmed Z, Ahmidouch A, Aljawrneh B, Alsalmi S, Ambrose R, Armstrong W, Asaturyan A, Assumin-Gyimah K, Ayerbe Gayoso C, Bandari A, Bane J, Basnet S, Berdnikov VV, Bericic J, Bhatt H, Bhetuwal D, Biswas D, Boeglin WU, Bosted P, Brash E, Bukhari MHS, Chen H, Chen JP, Chen M, Christy ME, Covrig S, Craycraft K, Danagoulian S, Day D, Diefenthaler M, Dlamini M, Dunne J, Duran B, Dutta D, Ent R, Evans R, Fenker H, Fomin N, Fuchey E, Gaskell D, Gautam TN, Gonzalez FA, Hansen JO, Hauenstein F, Hernandez AV, Horn T, Huber GM, Jones MK, Joosten S, Kabir ML, Karki A, Keppel CE, Khanal A, King P, Kinney E, Lashley-Colthirst N, Li S, Li WB, Liyanage AH, Mack DJ, Malace SP, Matter J, Meekins D, Michaels R, Mkrtchyan A, Mkrtchyan H, Nazeer SJ, Nanda S, Niculescu G, Niculescu M, Nguyen D, Nuruzzaman N, Pandey B, Park S, Perdrisat CF, Pooser E, Rehfuss M, Reinhold J, Sawatzky B, Smith GR, Sun A, Szumila-Vance H, Tadevosyan V, Wood SA, and Zhang J

Abstract

We measure ^{2}H(e,e^{'}p)n cross sections at 4-momentum transfers of Q^{2}=4.5±0.5  (GeV/c)^{2} over a range of neutron recoil momenta p_{r}, reaching up to ∼1.0  GeV/c. We obtain data at fixed neutron recoil angles θ_{nq}=35°, 45°, and 75° with respect to the 3-momentum transfer q[over →]. The new data agree well with previous data, which reached p_{r}∼500  MeV/c. At θ_{nq}=35° and 45°, final state interactions, meson exchange currents, and isobar currents are suppressed and the plane wave impulse approximation provides the dominant cross section contribution. We compare the new data to recent theoretical calculations, where we observe a significant discrepancy for recoil momenta p_{r}>700  MeV/c.

Published
2020
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17. Precision Measurement of the p(e,e^{'}p)π^{0} Reaction at Threshold.

Author

Chirapatpimol K, Shabestari MH, Lindgren RA, Smith LC, Annand JR, Higinbotham DW, Moffit B, Nelyubin V, Norum BE, Allada K, Aniol K, Ardashev K, Armstrong DS, Arndt RA, Benmokhtar F, Bernstein AM, Bertozzi W, Briscoe WJ, Bimbot L, Camsonne A, Chen JP, Choi S, Chudakov E, Cisbani E, Cusanno F, Dalton MM, Dutta C, Egiyan K, Fernàndez-Ramìrez C, Feuerbach R, Fissum KG, Frullani S, Garibaldi F, Gayou O, Gilman R, Gilad S, Goity J, Gomez J, Hahn B, Hamilton D, Hansen JO, Huang J, Igarashi R, Ireland D, de Jager CW, Jin X, Jiang X, Jinasundera T, Kellie J, Keppel CE, Kolb N, LeRose J, Liyanage N, Livingston K, McNulty D, Mercado L, Michaels R, Mihovilovič M, Qian S, Qian X, Mailyan S, Mamyan V, Marrone S, Monaghan P, Nanda S, Perdrisat CF, Piasetzky E, Protopopescu D, Punjabi V, Qiang Y, Rachek IA, Rakhman A, Riordan S, Ron G, Rosner G, Saha A, Sawatzky B, Shahinyan A, Širca S, Sparveris N, Subedi RR, Suleiman R, Strakovsky I, Sulkosky V, Moinelo J, Voskanyan H, Wang K, Wang Y, Watson J, Watts D, Wojtsekhowski B, Workman RL, Yao H, Zhan X, and Zhang Y

Abstract

New results are reported from a measurement of π^{0} electroproduction near threshold using the p(e,e^{'}p)π^{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. For the first time, complete coverage of the ϕ_{π}^{*} and θ_{π}^{*} angles in the pπ^{0} center of mass was obtained for invariant energies above threshold from 0.5 up to 15 MeV. The 4-momentum transfer Q^{2} coverage ranges from 0.05 to 0.155 (GeV/c)^{2} in fine steps. A simple phenomenological analysis of our data shows strong disagreement with p-wave predictions from ChPT for Q^{2}>0.07 (GeV/c)^{2}, while the s-wave predictions are in reasonable agreement.

Published
2015
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18. Separated response function ratios in exclusive, forward π(±) electroproduction.

Author

Huber GM, Blok HP, Butuceanu C, Gaskell D, Horn T, Mack DJ, Abbott D, Aniol K, Anklin H, Armstrong C, Arrington J, Assamagan K, Avery S, Baker OK, Barrett B, Beise EJ, Bochna C, Boeglin W, Brash EJ, Breuer H, Chang CC, Chant N, Christy ME, Dunne J, Eden T, Ent R, Fenker H, Gibson EF, Gilman R, Gustafsson K, Hinton W, Holt RJ, Jackson H, Jin S, Jones MK, Keppel CE, Kim PH, Kim W, King PM, Klein A, Koltenuk D, Kovaltchouk V, Liang M, Liu J, Lolos GJ, Lung A, Margaziotis DJ, Markowitz P, Matsumura A, McKee D, Meekins D, Mitchell J, Miyoshi T, Mkrtchyan H, Mueller B, Niculescu G, Niculescu I, Okayasu Y, Pentchev L, Perdrisat C, Pitz D, Potterveld D, Punjabi V, Qin LM, Reimer PE, Reinhold J, Roche J, Roos PG, Sarty A, Shin IK, Smith GR, Stepanyan S, Tang LG, Tadevosyan V, Tvaskis V, van der Meer RL, Vansyoc K, Van Westrum D, Vidakovic S, Volmer J, Vulcan W, Warren G, Wood SA, Xu C, Yan C, Zhao WX, Zheng X, and Zihlmann B

Abstract

The study of exclusive π(±) electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio RL=σL(π-)/σL(π+) is sensitive to isoscalar contamination to the dominant isovector pion exchange amplitude, which is the basis for the determination of the charged pion form factor from electroproduction data. A change in the value of RT=σT(π-)/σT(π+) from unity at small -t, to 1/4 at large -t, would suggest a transition from coupling to a (virtual) pion to coupling to individual quarks. Furthermore, the mentioned ratios may show an earlier approach to perturbative QCD than the individual cross sections. We have performed the first complete separation of the four unpolarized electromagnetic structure functions above the dominant resonances in forward, exclusive π(±) electroproduction on the deuteron at central Q(2) values of 0.6, 1.0, 1.6  GeV(2) at W=1.95  GeV, and Q(2)=2.45  GeV(2) at W=2.22  GeV. Here, we present the L and T cross sections, with emphasis on RL and RT, and compare them with theoretical calculations. Results for the separated ratio RL indicate dominance of the pion-pole diagram at low -t, while results for RT are consistent with a transition between pion knockout and quark knockout mechanisms.

Published
2014
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19. Measurement of muon neutrino quasielastic scattering on a hydrocarbon target at Eν ~ 3.5 GeV.

Author

Fiorentini GA, Schmitz DW, Rodrigues PA, Aliaga L, Altinok O, Baldin B, Baumbaugh A, Bodek A, Boehnlein D, Boyd S, Bradford R, Brooks WK, Budd H, Butkevich A, Martinez Caicedo DA, Castromonte CM, Christy ME, Chung H, Chvojka J, Clark M, da Motta H, Damiani DS, Danko I, Datta M, Day M, DeMaat R, Devan J, Draeger E, Dytman SA, Díaz GA, Eberly B, Edmondson DA, Felix J, Fields L, Fitzpatrick T, Gago AM, Gallagher H, George CA, Gielata JA, Gingu C, Gobbi B, Gran R, Grossman N, Hanson J, Harris DA, Heaton J, Higuera A, Howley IJ, Hurtado K, Jerkins M, Kafka T, Kaisen J, Kanter MO, Keppel CE, Kilmer J, Kordosky M, Krajeski AH, Kulagin SA, Le T, Lee H, Leister AG, Locke G, Maggi G, Maher E, Manly S, Mann WA, Marshall CM, McFarland KS, McGivern CL, McGowan AM, Mislivec A, Morfín JG, Mousseau J, Naples D, Nelson JK, Niculescu G, Niculescu I, Ochoa N, O'Connor CD, Olsen J, Osmanov B, Osta J, Palomino JL, Paolone V, Park J, Patrick CE, Perdue GN, Peña C, Rakotondravohitra L, Ransome RD, Ray H, Ren L, Rude C, Sassin KE, Schellman H, Schneider RM, Schulte EC, Simon C, Snider FD, Snyder MC, Sobczyk JT, Solano Salinas CJ, Tagg N, Tan W, Tice BG, Tzanakos G, Velásquez JP, Walding J, Walton T, Wolcott J, Wolthuis BA, Woodward N, Zavala G, Zeng HB, Zhang D, Zhu LY, and Ziemer BP

Abstract

We report a study of ν(μ) charged-current quasielastic events in the segmented scintillator inner tracker of the MINERvA experiment running in the NuMI neutrino beam at Fermilab. The events were selected by requiring a μ- and low calorimetric recoil energy separated from the interaction vertex. We measure the flux-averaged differential cross section, dσ/dQ², and study the low energy particle content of the final state. Deviations are found between the measured dσ/dQ² and the expectations of a model of independent nucleons in a relativistic Fermi gas. We also observe an excess of energy near the vertex consistent with multiple protons in the final state.

Published
2013
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20. Measurement of muon antineutrino quasielastic scattering on a hydrocarbon target at Eν ~ 3.5 GeV.

Author

Fields L, Chvojka J, Aliaga L, Altinok O, Baldin B, Baumbaugh A, Bodek A, Boehnlein D, Boyd S, Bradford R, Brooks WK, Budd H, Butkevich A, Martinez Caicedo DA, Castromonte CM, Christy ME, Chung H, Clark M, da Motta H, Damiani DS, Danko I, Datta M, Day M, DeMaat R, Devan J, Draeger E, Dytman SA, Díaz GA, Eberly B, Edmondson DA, Felix J, Fitzpatrick T, Fiorentini GA, Gago AM, Gallagher H, George CA, Gielata JA, Gingu C, Gobbi B, Gran R, Grossman N, Hanson J, Harris DA, Heaton J, Higuera A, Howley IJ, Hurtado K, Jerkins M, Kafka T, Kaisen J, Kanter MO, Keppel CE, Kilmer J, Kordosky M, Krajeski AH, Kulagin SA, Le T, Lee H, Leister AG, Locke G, Maggi G, Maher E, Manly S, Mann WA, Marshall CM, McFarland KS, McGivern CL, McGowan AM, Mislivec A, Morfín JG, Mousseau J, Naples D, Nelson JK, Niculescu G, Niculescu I, Ochoa N, O'Connor CD, Olsen J, Osmanov B, Osta J, Palomino JL, Paolone V, Park J, Patrick CE, Perdue GN, Peña C, Rakotondravohitra L, Ransome RD, Ray H, Ren L, Rodrigues PA, Rude C, Sassin KE, Schellman H, Schmitz DW, Schneider RM, Schulte EC, Simon C, Snider FD, Snyder MC, Sobczyk JT, Solano Salinas CJ, Tagg N, Tan W, Tice BG, Tzanakos G, Velásquez JP, Walding J, Walton T, Wolcott J, Wolthuis BA, Woodward N, Zavala G, Zeng HB, Zhang D, Zhu LY, and Ziemer BP

Abstract

We have isolated ν(μ) charged-current quasielastic (QE) interactions occurring in the segmented scintillator tracking region of the MINERvA detector running in the NuMI neutrino beam at Fermilab. We measure the flux-averaged differential cross section, dσ/dQ², and compare to several theoretical models of QE scattering. Good agreement is obtained with a model where the nucleon axial mass, M(A), is set to 0.99 GeV/c² but the nucleon vector form factors are modified to account for the observed enhancement, relative to the free nucleon case, of the cross section for the exchange of transversely polarized photons in electron-nucleus scattering. Our data at higher Q² favor this interpretation over an alternative in which the axial mass is increased.

Published
2013
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21. Moments of the longitudinal proton structure function FL from global data in the Q(2) range 0.75-45.0  (GeV/c)(2).

Author

Monaghan P, Accardi A, Christy ME, Keppel CE, Melnitchouk W, and Zhu L

Abstract

We present an extraction of the lowest three moments of the proton longitudinal structure function FL from world data between Q(2)=0.75 and 45  (GeV/c)(2). The availability of new FL data at low Bjorken x from HERA and at large x from Jefferson Lab allows the first determination of these moments over a large Q(2) range, relatively free from uncertainties associated with extrapolations into unmeasured regions. The moments are found to be underestimated by leading twist structure function parametrizations, especially for the higher moments, suggesting either the presence of significant higher twist effects in FL and/or a larger gluon distribution at high x.

Published
2013
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22. Measurement of the neutron F2 structure function via spectator tagging with CLAS.

Author

Baillie N, Tkachenko S, Zhang J, Bosted P, Bültmann S, Christy ME, Fenker H, Griffioen KA, Keppel CE, Kuhn SE, Melnitchouk W, Tvaskis V, Adhikari KP, Adikaram D, Aghasyan M, Amaryan MJ, Anghinolfi M, Arrington J, Avakian H, Baghdasaryan H, Battaglieri M, Biselli AS, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Carman DS, Celentano A, Chandavar S, Charles G, Cole PL, Contalbrigo M, Crede V, D'Angelo A, Daniel A, Dashyan N, De Vita R, De Sanctis E, Deur A, Dey B, Djalali C, Dodge G, Domingo J, Doughty D, Dupre R, Dutta D, Ent R, Egiyan H, El Alaoui A, El Fassi L, Elouadrhiri L, Eugenio P, Fedotov G, Fegan S, Fradi A, Gabrielyan MY, Gevorgyan N, Gilfoyle GP, Giovanetti KL, Girod FX, Gohn W, Golovatch E, Gothe RW, Graham L, Guegan B, Guidal M, Guler N, Guo L, Hafidi K, Heddle D, Hicks K, Holtrop M, Hungerford E, Hyde CE, Ilieva Y, Ireland DG, Ispiryan M, Isupov EL, Jawalkar SS, Jo HS, Kalantarians N, Khandaker M, Khetarpal P, Kim A, Kim W, King PM, Klein A, Klein FJ, Klimenko A, Kubarovsky V, Kuleshov SV, Kvaltine ND, Livingston K, Lu HY, MacGregor IJ, Mao Y, Markov N, McKinnon B, Mineeva T, Morrison B, Moutarde H, Munevar E, Nadel-Turonski P, Ni A, Niccolai S, Niculescu I, Niculescu G, Osipenko M, Ostrovidov AI, Pappalardo L, Park K, Park S, Pasyuk E, Anefalos Pereira S, Pisano S, Pozdniakov S, Price JW, Procureur S, Prok Y, Protopopescu D, Raue BA, Ricco G, Rimal D, Ripani M, Rosner G, Rossi P, Sabatié F, Saini MS, Salgado C, Schott D, Schumacher RA, Seder E, Sharabian YG, Sober DI, Sokhan D, Stepanyan S, Stepanyan SS, Stoler P, Strauch S, Taiuti M, Tang W, Ungaro M, Vineyard MF, Voutier E, Watts DP, Weinstein LB, Weygand DP, Wood MH, Zana L, and Zhao B

Abstract

We report on the first measurement of the F(2) structure function of the neutron from the semi-inclusive scattering of electrons from deuterium, with low-momentum protons detected in the backward hemisphere. Restricting the momentum of the spectator protons to ≲100 MeV/c and their angles to ≳100° relative to the momentum transfer allows an interpretation of the process in terms of scattering from nearly on-shell neutrons. The F(2)(n) data collected cover the nucleon-resonance and deep-inelastic regions over a wide range of Bjorken x for 0.65

Published
2012
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23. New measurements of high-momentum nucleons and short-range structures in nuclei.

Author

Fomin N, Arrington J, Asaturyan R, Benmokhtar F, Boeglin W, Bosted P, Bruell A, Bukhari MH, Christy ME, Chudakov E, Clasie B, Connell SH, Dalton MM, Daniel A, Day DB, Dutta D, Ent R, El Fassi L, Fenker H, Filippone BW, Garrow K, Gaskell D, Hill C, Holt RJ, Horn T, Jones MK, Jourdan J, Kalantarians N, Keppel CE, Kiselev D, Kotulla M, Lindgren R, Lung AF, Malace S, Markowitz P, McKee P, Meekins DG, Mkrtchyan H, Navasardyan T, Niculescu G, Opper AK, Perdrisat C, Potterveld DH, Punjabi V, Qian X, Reimer PE, Roche J, Rodriguez VM, Rondon O, Schulte E, Seely J, Segbefia E, Slifer K, Smith GR, Solvignon P, Tadevosyan V, Tajima S, Tang L, Testa G, Trojer R, Tvaskis V, Vulcan WF, Wasko C, Wesselmann FR, Wood SA, Wright J, and Zheng X

Abstract

We present new measurements of electron scattering from high-momentum nucleons in nuclei. These data allow an improved determination of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data also include the kinematic region where three-nucleon correlations are expected to dominate.

Published
2012
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24. Precise extraction of the induced polarization in the 4He(e,e'p)3H reaction.

Author

Malace SP, Paolone M, Strauch S, Albayrak I, Arrington J, Berman BL, Brash EJ, Briscoe B, Camsonne A, Chen JP, Christy ME, Chudakov E, Cisbani E, Craver B, Cusanno F, Ent R, Garibaldi F, Gilman R, Glamazdin O, Glister J, Higinbotham DW, Hyde-Wright CE, Ilieva Y, de Jager CW, Jiang X, Jones MK, Keppel CE, Khrosinkova E, Kuchina E, Kumbartzki G, Lee B, Lindgren R, Margaziotis DJ, Meekins D, Michaels R, Park K, Pentchev L, Perdrisat CF, Piasetzky E, Punjabi VA, Puckett AJ, Qian X, Qiang Y, Ransome RD, Saha A, Sarty AJ, Schulte E, Solvignon P, Subedi RR, Tang L, Tedeschi D, Tvaskis V, Udias JM, Ulmer PE, Vignote JR, Wesselmann FR, Wojtsekhowski B, and Zhan X

Abstract

We measured with unprecedented precision the induced polarization P(y) in (4)He(e,e'p)(3)H at Q(2)=0.8 and 1.3  (GeV/c)(2). The induced polarization is indicative of reaction-mechanism effects beyond the impulse approximation. Our results are in agreement with a relativistic distorted-wave impulse approximation calculation but are overestimated by a calculation with strong charge-exchange effects. Our data are used to constrain the strength of the spin-independent charge-exchange term in the latter calculation.

Published
2011
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25. Scaling of the F2 structure function in nuclei and quark distributions at x>1.

Author

Fomin N, Arrington J, Day DB, Gaskell D, Daniel A, Seely J, Asaturyan R, Benmokhtar F, Boeglin W, Boillat B, Bosted P, Bruell A, Bukhari MH, Christy ME, Chudakov E, Clasie B, Connell SH, Dalton MM, Dutta D, Ent R, El Fassi L, Fenker H, Filippone BW, Garrow K, Hill C, Holt RJ, Horn T, Jones MK, Jourdan J, Kalantarians N, Keppel CE, Kiselev D, Kotulla M, Lindgren R, Lung AF, Malace S, Markowitz P, McKee P, Meekins DG, Miyoshi T, Mkrtchyan H, Navasardyan T, Niculescu G, Okayasu Y, Opper AK, Perdrisat C, Potterveld DH, Punjabi V, Qian X, Reimer PE, Roche J, Rodriguez VM, Rondon O, Schulte E, Segbefia E, Slifer K, Smith GR, Solvignon P, Tadevosyan V, Tajima S, Tang L, Testa G, Trojer R, Tvaskis V, Vulcan WF, Wasko C, Wesselmann FR, Wood SA, Wright J, and Zheng X

Abstract

We present new data on electron scattering from a range of nuclei taken in Hall C at Jefferson Lab. For heavy nuclei, we observe a rapid falloff in the cross section for x>1, which is sensitive to short-range contributions to the nuclear wave function, and in deep inelastic scattering corresponds to probing extremely high momentum quarks. This result agrees with higher energy muon scattering measurements, but is in sharp contrast to neutrino scattering measurements which suggested a dramatic enhancement in the distribution of the "superfast" quarks probed at x>1. The falloff at x>1 is noticeably stronger in 2H and 3He, but nearly identical for all heavier nuclei.

Published
2010
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26. Probing quark-gluon interactions with transverse polarized scattering.

Author

Slifer K, Rondón OA, Aghalaryan A, Ahmidouch A, Asaturyan R, Bloch F, Boeglin W, Bosted P, Carasco C, Carlini R, Cha J, Chen JP, Christy ME, Cole L, Coman L, Crabb D, Danagoulian S, Day D, Dunne J, Elaasar M, Ent R, Fenker H, Frlez E, Gaskell D, Gan L, Gomez J, Hu B, Jourdan J, Jones MK, Keith C, Keppel CE, Khandaker M, Klein A, Kramer L, Liang Y, Lichtenstadt J, Lindgren R, Mack D, McKee P, McNulty D, Meekins D, Mkrtchyan H, Nasseripour R, Niculescu I, Normand K, Norum B, Pocanic D, Prok Y, Raue B, Reinhold J, Roche J, Kiselev D, Savvinov N, Sawatzky B, Seely M, Sick I, Smith C, Smith G, Stepanyan S, Tang L, Tajima S, Testa G, Vulcan W, Wang K, Warren G, Wesselmann FR, Wood S, Yan C, Yuan L, Yun J, Zeier M, and Zhu H

Abstract

We have extracted QCD matrix elements from our data on doubly polarized inelastic scattering of electrons on nuclei. We find the higher twist matrix element d˜2, which arises strictly from quark-gluon interactions, to be unambiguously nonzero. The data also reveal an isospin dependence of higher twist effects if we assume that the Burkhardt-Cottingham sum rule is valid. The fundamental Bjorken sum rule obtained from the a0 matrix element is satisfied at our low momentum transfer.

Published
2010
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27. Polarization transfer in the 4He(e,e'p)3H reaction at Q2=0.8 and 1.3 (GeV/c)2.

Author

Paolone M, Malace SP, Strauch S, Albayrak I, Arrington J, Berman BL, Brash EJ, Briscoe B, Camsonne A, Chen JP, Christy ME, Chudakov E, Cisbani E, Craver B, Cusanno F, Ent R, Garibaldi F, Gilman R, Glamazdin O, Glister J, Higinbotham DW, Hyde-Wright CE, Ilieva Y, de Jager CW, Jiang X, Jones MK, Keppel CE, Khrosinkova E, Kuchina E, Kumbartzki G, Lee B, Lindgren R, Margaziotis DJ, Meekins D, Michaels R, Park K, Pentchev L, Perdrisat CF, Piasetzky E, Punjabi VA, Puckett AJ, Qian X, Qiang Y, Ransome RD, Saha A, Sarty AJ, Schulte E, Solvignon P, Subedi RR, Tang L, Tedeschi D, Tvaskis V, Udias JM, Ulmer PE, Vignote JR, Wesselmann FR, Wojtsekhowski B, and Zhan X

Abstract

Proton recoil polarization was measured in the quasielastic 4He(e,e'p)3H reaction at Q{2}=0.8 and 1.3  (GeV/c){2} with unprecedented precision. The polarization-transfer coefficients are found to differ from those of the 1H(e,e'p) reaction, contradicting a relativistic distorted-wave approximation and favoring either the inclusion of medium-modified proton form factors predicted by the quark-meson coupling model or a spin-dependent charge-exchange final-state interaction. For the first time, the polarization-transfer ratio is studied as a function of the virtuality of the proton.

Published
2010
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28. Confirmation of quark-hadron duality in the neutron F2 structure function.

Author

Malace SP, Kahn Y, Melnitchouk W, and Keppel CE

Abstract

We apply a recently developed technique to extract for the first time the neutron F(2)(n) structure function from inclusive proton and deuteron data in the nucleon resonance region, and test the validity of quark-hadron duality in the neutron. We establish the accuracy of duality in the low-lying neutron resonance regions over a range of Q(2), and compare with the corresponding results on the proton and with theoretical expectations. The confirmation of duality in both the neutron and proton opens the possibility of using resonance region data to constrain parton distributions at large x.

Published
2010
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29. New measurements of the European Muon Collaboration effect in very light nuclei.

Author

Seely J, Daniel A, Gaskell D, Arrington J, Fomin N, Solvignon P, Asaturyan R, Benmokhtar F, Boeglin W, Boillat B, Bosted P, Bruell A, Bukhari MH, Christy ME, Clasie B, Connell S, Dalton MM, Day D, Dunne J, Dutta D, El Fassi L, Ent R, Fenker H, Filippone BW, Gao H, Hill C, Holt RJ, Horn T, Hungerford E, Jones MK, Jourdan J, Kalantarians N, Keppel CE, Kiselev D, Kotulla M, Lee C, Lung AF, Malace S, Meekins DG, Mertens T, Mkrtchyan H, Navasardyan T, Niculescu G, Niculescu I, Nomura H, Okayasu Y, Opper AK, Perdrisat C, Potterveld DH, Punjabi V, Qian X, Reimer PE, Roche J, Rodriguez VM, Rondon O, Schulte E, Segbefia E, Slifer K, Smith GR, Tadevosyan V, Tajima S, Tang L, Testa G, Trojer R, Tvaskis V, Vulcan WF, Wesselmann FR, Wood SA, Wright J, Yuan L, and Zheng X

Abstract

New Jefferson Lab data are presented on the nuclear dependence of the inclusive cross section from (2)H, (3)He, (4)He, (9)Be and (12)C for 0.3 < x < 0.9, Q(2) approximately 3-6 GeV(2). These data represent the first measurement of the EMC effect for (3)He at large x and a significant improvement for (4)He. The data do not support previous A-dependent or density-dependent fits to the EMC effect and suggest that the nuclear dependence of the quark distributions may depend on the local nuclear environment.

Published
2009
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30. Measurement of nuclear transparency for the A(e,e'pi+) reaction.

Author

Clasie B, Qian X, Arrington J, Asaturyan R, Benmokhtar F, Boeglin W, Bosted P, Bruell A, Christy ME, Chudakov E, Cosyn W, Dalton MM, Daniel A, Day D, Dutta D, El Fassi L, Ent R, Fenker HC, Ferrer J, Fomin N, Gao H, Garrow K, Gaskell D, Gray C, Horn T, Huber GM, Jones MK, Kalantarians N, Keppel CE, Kramer K, Larson A, Li Y, Liang Y, Lung AF, Malace S, Markowitz P, Matsumura A, Meekins DG, Mertens T, Miller GA, Miyoshi T, Mkrtchyan H, Monson R, Navasardyan T, Niculescu G, Niculescu I, Okayasu Y, Opper AK, Perdrisat C, Punjabi V, Rauf AW, Rodriquez VM, Rohe D, Ryckebusch J, Seely J, Segbefia E, Smith GR, Strikman M, Sumihama M, Tadevosyan V, Tang L, Tvaskis V, Villano A, Vulcan WF, Wesselmann FR, Wood SA, Yuan L, and Zheng XC

Abstract

We have measured the nuclear transparency of the A(e,e'pi+) process in 2H, 12C, 27Al, 63Cu, and 197Au targets. These measurements were performed at the Jefferson Laboratory over a four momentum transfer squared range Q2=1.1 to 4.7 (GeV/c)2. The nuclear transparency was extracted as the super-ratio of (sigmaA/sigmaH) from data to a model of pion-electroproduction from nuclei without pi-N final-state interactions. The Q2 and atomic number dependence of the nuclear transparency both show deviations from traditional nuclear physics expectations and are consistent with calculations that include the quantum chromodynamical phenomenon of color transparency.

Published
2007
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31. Longitudinal-transverse separations of deep-inelastic structure functions at low Q2 for hydrogen and deuterium.

Author

Tvaskis V, Christy ME, Arrington J, Asaturyan R, Baker OK, Blok HP, Bosted P, Boswell M, Bruell A, Cochran A, Cole L, Crowder J, Dunne J, Ent R, Fenker HC, Filippone BW, Garrow K, Gasparian A, Gomez J, Jackson HE, Keppel CE, Kinney E, Lapikás L, Liang Y, Lorenzon W, Lung A, Mack DJ, Martin JW, McIlhany K, Meekins D, Milner RG, Mitchell JH, Mkrtchyan H, Moreland B, Nazaryan V, Niculescu I, Opper A, Piercey RB, Potterveld DH, Rose B, Sato Y, Seo W, Smith G, Spurlock K, van der Steenhoven G, Stepanyan S, Tadevosian V, Uzzle A, Vulcan WF, Wood SA, Zihlmann B, and Ziskin V

Abstract

We report on a study of the longitudinal to transverse cross section ratio, R=sigmaL/sigmaT, at low values of x and Q2, as determined from inclusive inelastic electron-hydrogen and electron-deuterium scattering data from Jefferson Laboratory Hall C spanning the four-momentum transfer range 0.06

Published
2007
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32. Proton spin structure in the resonance region.

Author

Wesselmann FR, Slifer K, Tajima S, Aghalaryan A, Ahmidouch A, Asaturyan R, Bloch F, Boeglin W, Bosted P, Carasco C, Carlini R, Cha J, Chen JP, Christy ME, Cole L, Coman L, Crabb D, Danagoulian S, Day D, Dunne J, Elaasar M, Ent R, Fenker H, Frlez E, Gan L, Gaskell D, Gomez J, Hu B, Jones MK, Jourdan J, Keith C, Keppel CE, Khandaker M, Klein A, Kramer L, Liang Y, Lichtenstadt J, Lindgren R, Mack D, McKee P, McNulty D, Meekins D, Mkrtchyan H, Nasseripour R, Niculescu I, Normand K, Norum B, Pocanic D, Prok Y, Raue B, Reinhold J, Roche J, Rohe D, Rondón OA, Savvinov N, Sawatzky B, Seely M, Sick I, Smith C, Smith G, Stepanyan S, Tang L, Testa G, Vulcan W, Wang K, Warren G, Wood S, Yan C, Yuan L, Yun J, Zeier M, and Zhu H

Abstract

We have examined the spin structure of the proton in the region of the nucleon resonances (1.085 GeV

Published
2007
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33. Onset of quark-hadron duality in pion electroproduction.

Author

Navasardyan T, Adams GS, Ahmidouch A, Angelescu T, Arrington J, Asaturyan R, Baker OK, Benmouna N, Bertoncini C, Blok HP, Boeglin WU, Bosted PE, Breuer H, Christy ME, Connell SH, Cui Y, Dalton MM, Danagoulian S, Day D, Dodario T, Dunne JA, Dutta D, El Khayari N, Ent R, Fenker HC, Frolov VV, Gan L, Gaskell D, Hafidi K, Hinton W, Holt RJ, Horn T, Huber GM, Hungerford E, Jiang X, Jones M, Joo K, Kalantarians N, Kelly JJ, Keppel CE, Kubarovski V, Li Y, Liang Y, Malace S, Markowitz P, McGrath E, McKee P, Meekins DG, Mkrtchyan H, Moziak B, Niculescu G, Niculescu I, Opper AK, Ostapenko T, Reimer P, Reinhold J, Roche J, Rock SE, Schulte E, Segbefia E, Smith C, Smith GR, Stoler P, Tadevosyan V, Tang L, Ungaro M, Uzzle A, Vidakovic S, Villano A, Vulcan WF, Wang M, Warren G, Wesselmann F, Wojtsekhowski B, Wood SA, Xu C, Yuan L, Zheng X, and Zhu H

Abstract

A large data set of charged-pion (pi+/-) electroproduction from both hydrogen and deuterium targets has been obtained spanning the low-energy residual-mass region. These data conclusively show the onset of the quark-hadron duality phenomenon, as predicted for high-energy hadron electroproduction. We construct several ratios from these data to exhibit the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark-->pion production mechanisms.

Published
2007
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34. Determination of the pion charge form factor at Q2=1.60 and 2.45 (GeV/c)2.

Author

Horn T, Aniol K, Arrington J, Barrett B, Beise EJ, Blok HP, Boeglin W, Brash EJ, Breuer H, Chang CC, Christy ME, Ent R, Gaskell D, Gibson E, Holt RJ, Huber GM, Jin S, Jones MK, Keppel CE, Kim W, King PM, Kovaltchouk V, Liu J, Lolos GJ, Mack DJ, Margaziotis DJ, Markowitz P, Matsumura A, Meekins D, Miyoshi T, Mkrtchyan H, Niculescu I, Okayasu Y, Pentchev L, Perdrisat C, Potterveld D, Punjabi V, Reimer P, Reinhold J, Roche J, Roos PG, Sarty A, Smith GR, Tadevosyan V, Tang LG, Tvaskis V, Vidakovic S, Volmer J, Vulcan W, Warren G, Wood SA, Xu C, and Zheng X

Abstract

The 1H(e,e'pi+)n cross section was measured at four-momentum transfers of Q2=1.60 and 2.45 GeV2 at an invariant mass of the photon nucleon system of W=2.22 GeV. The charged pion form factor (F(pi)) was extracted from the data by comparing the separated longitudinal pion electroproduction cross section to a Regge model prediction in which F(pi) is a free parameter. The results indicate that the pion form factor deviates from the charge-radius constrained monopole form at these values of Q2 by one sigma, but is still far from its perturbative quantum chromodynamics prediction.

Published
2006
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35. Precision Rosenbluth measurement of the proton elastic form factors.

Author

Qattan IA, Arrington J, Segel RE, Zheng X, Aniol K, Baker OK, Beams R, Brash EJ, Calarco J, Camsonne A, Chen JP, Christy ME, Dutta D, Ent R, Frullani S, Gaskell D, Gayou O, Gilman R, Glashausser C, Hafidi K, Hansen JO, Higinbotham DW, Hinton W, Holt RJ, Huber GM, Ibrahim H, Jisonna L, Jones MK, Keppel CE, Kinney E, Kumbartzki GJ, Lung A, Margaziotis DJ, McCormick K, Meekins D, Michaels R, Monaghan P, Moussiegt P, Pentchev L, Perdrisat C, Punjabi V, Ransome R, Reinhold J, Reitz B, Saha A, Sarty A, Schulte EC, Slifer K, Solvignon P, Sulkosky V, Wijesooriya K, and Zeidman B

Abstract

We report the results of a new Rosenbluth measurement of the proton electromagnetic form factors at Q2 values of 2.64, 3.20, and 4.10 GeV2. Cross sections were determined by detecting the recoiling proton, in contrast to previous measurements which detected the scattered electron. Cross sections were determined to 3%, with relative uncertainties below 1%. The ratio mu(p)G(E)/G(M) was determined to 4%-8% and showed mu(p)G(E)/G(M) approximately 1. These results are consistent with, and much more precise than, previous Rosenbluth extractions. They are inconsistent with recent polarization transfer measurements of similar precision, implying a systematic difference between the techniques.

Published
2005
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36. Correlated strength in the nuclear spectral function.

Author

Rohe D, Armstrong CS, Asaturyan R, Baker OK, Bueltmann S, Carasco C, Day D, Ent R, Fenker HC, Garrow K, Gasparian A, Gueye P, Hauger M, Honegger A, Jourdan J, Keppel CE, Kubon G, Lindgren R, Lung A, Mack DJ, Mitchell JH, Mkrtchyan H, Mocelj D, Normand K, Petitjean T, Rondon O, Segbefia E, Sick I, Stepanyan S, Tang L, Tiefenbacher F, Vulcan WF, Warren G, Wood SA, Yuan L, Zeier M, Zhu H, and Zihlmann B

Abstract

We have carried out an (e,e'p) experiment at high momentum transfer and in parallel kinematics to measure the strength of the nuclear spectral function S(k,E) at high nucleon momenta k and large removal energies E. This strength is related to the presence of short-range and tensor correlations, and was known hitherto only indirectly and with considerable uncertainty from the lack of strength in the independent-particle region. This experiment locates by direct measurement the correlated strength predicted by theory.

Published
2004
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37. Polarization transfer in the 4He(e-->,e'p-->)3H reaction up to Q2=2.6 (GeV/c)2.

Author

Strauch S, Dieterich S, Aniol KA, Annand JR, Baker OK, Bertozzi W, Boswell M, Brash EJ, Chai Z, Chen JP, Christy ME, Chudakov E, Cochran A, De Leo R, Ent R, Epstein MB, Finn JM, Fissum KG, Forest TA, Frullani S, Garibaldi F, Gasparian A, Gayou O, Gilad S, Gilman R, Glashausser C, Gomez J, Gorbenko V, Gueye PL, Hansen JO, Higinbotham DW, Hu B, Hyde-Wright CE, Ireland DG, Jackson C, de Jager CW, Jiang X, Jones C, Jones MK, Kellie JD, Kelly JJ, Keppel CE, Kumbartzki G, Kuss M, LeRose JJ, Livingston K, Liyanage N, Malov S, Margaziotis DJ, Meekins D, Michaels R, Mitchell JH, Nanda SK, Nappa J, Perdrisat CF, Punjabi VA, Ransome RD, Roché R, Rosner G, Rvachev M, Sabatie F, Saha A, Sarty A, Udias JM, Ulmer PE, Urciuoli GM, van den Brand JF, Vignote JR, Watts DP, Weinstein LB, Wijesooriya K, and Wojtsekhowski B

Abstract

We have measured the proton recoil polarization in the 4He(e-->,e(')p-->)4H reaction at Q(2)=0.5, 1.0, 1.6, and 2.6 (GeV/c)(2). The measured ratio of polarization transfer coefficients differs from a fully relativistic calculation, favoring the inclusion of a medium modification of the proton form factors predicted by a quark-meson coupling model. In addition, the measured induced polarizations agree reasonably well with the fully relativistic calculation indicating that the treatment of final-state interactions is under control.

Published
2003
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38. Perturbative QCD analysis of local duality in a fixed w2 framework.

Author

Liuti S, Ent R, Keppel CE, and Niculescu I

Abstract

We study the Q2 dependence of large x F2 nucleon structure function data, with the aim of providing a perturbative QCD based, quantitative analysis of parton-hadron duality. As opposed to previous analyses at fixed x, we use a framework in fixed W2. We uncover a breakdown of the twist-4 approximation with a renormalon type improvement at O(1/Q(4)) which affects the initial evolution of parton distributions.

Published
2002
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39. Measurement of the high energy two-body deuteron photodisintegration differential cross section.

Author

Schulte EC, Ahmidouch A, Armstrong CS, Arrington J, Asaturyan R, Avery S, Baker OK, Beck DH, Blok HP, Bochna CW, Boeglin W, Bosted PY, Bouwhuis M, Breuer H, Brown DS, Bruell A, Cadman RV, Carlini R, Chant NS, Cochran A, Cole L, Danagoulian S, Day DB, Dunne JA, Dutta D, Ent R, Fenker HC, Fox B, Gan L, Gao H, Garrow K, Gaskell D, Gasparian A, Geesaman DF, Gilman R, Glashausser C, Gueye P, Harvey M, Holt RJ, Jackson HE, Jiang X, Keppel CE, Kinney ER, Liang Y, Lorenzon W, Lung AF, Mack DJ, Markowitz PE, Martin J, McIlhany K, McKee D, Meekins DG, Miller MA, Milner RG, Mitchell JH, Mkrtchyan H, Mueller BA, Nathan AM, Niculescu G, Niculescu I, O'Neill TG, Papavassiliou V, Pate SF, Piercey RB, Potterveld DH, Ransome RD, Reinhold J, Rollinde E, Roos P, Saha A, Sarty AJ, Sawafta R, Segbefia E, Shin T, Stepanyan S, Strauch S, Sutter MF, Tadevosyan V, Tang L, Tieulent R, Uzzle A, Vulcan WF, Wood SA, Xiong F, Yuan L, Zeier M, Zihlmann B, and Ziskin V

Abstract

The first measurements of the d(gamma,p)n differential cross section at forward angles and photon energies above 4 GeV were performed at the Thomas Jefferson National Accelerator Facility (JLab). The results indicate evidence of an angular dependent scaling threshold. Results at straight theta(cm) = 37 degrees are consistent with the constituent counting rules for E(gamma) greater, similar 4 GeV, while those at 70 degrees are consistent with the constituent counting rules for E(gamma) greater, similar 1.5 GeV.

Published
2001
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40. Experimental verification of quark-hadron duality

Author

Niculescu I I, Armstrong CS, Arrington J, Assamagan KA, Baker OK, Beck DH, Bochna CW, Carlini RD, Cha J, Cothran C, Day DB, Dunne JA, Dutta D, Ent R, Filippone BW, Frolov VV, Gao H, Geesaman DF, Gueye PL, Hinton W, Holt RJ, Jackson HE, Keppel CE, Koltenuk DM, Mack DJ, and Meekins DG

Abstract

A newly obtained sample of inclusive electron-nucleon scattering data has been analyzed for precision tests of quark-hadron duality. The data are in the nucleon resonance region, and span the range 0. 3

Published
2000
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41. Evidence for valencelike quark-hadron duality

Author

Niculescu I I, Armstrong CS, Arrington J, Assamagan KA, Baker OK, Beck DH, Bochna CW, Carlini RD, Cha J, Cothran C, Day DB, Dunne JA, Dutta D, Ent R, Frolov VV, Gao H, Geesaman DF, Gueye PL, Hinton W, Holt RJ, Jackson HE, Keppel CE, Koltenuk DM, Mack DJ, Meekins DG, and Miller MA

Abstract

A newly obtained data sample of inclusive electron-nucleon scattering from both hydrogen and deuterium targets is analyzed. These JLab data span the nucleon resonance region up to four-momentum transfers of 5 (GeV/c)(2). The data are found to follow an average scaling curve. The inclusion of low-momentum transfer data yields a scaling curve resembling deep inelastic neutrino-nucleus scattering data, suggesting a sensitivity to valencelike structure only.

Published
2000
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42. Inclusive electron scattering from nuclei at x~=1.

Author

Arrington J, Anthony P, Arnold RG, Beise EJ, Belz JE, Bosted PE, Bulten H, Chapman MS, Coulter KP, Dietrich F, Ent R, Epstein M, Filippone BW, Gao H, Gearhart RA, Geesaman DF, Hansen J, Holt RJ, Jackson HE, Jones CE, Keppel CE, Kinney ER, Kuhn S, Lee K, Lorenzon W, Lung A, Makins NC, Margaziotis DJ, McKeown RD, Milner RG, Mueller B, Napolitano J, Nelson J, O'Neill TG, Papavassiliou V V, Petratos GG, Potterveld DH, Rock SE, Spengos M, Szalata ZM, Tao LH, van Bibber K, van den Brand JF, White JL, Winter D, and Zeidman B

Published
1996
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43. Evidence for virtual Compton scattering from the proton.

Author

van den Brand JF, Ent R, Anthony PL, Arnold RG, Arrington J, Beise EJ, Belz JE, Bosted PE, Bulten H, Chapman MS, Coulter KP, Dietrich FS, Epstein M, Filippone BW, Gao H, Gearhart RA, Geesaman DF, Hansen J, Holt RJ, Jackson HE, Jones CE, Keppel CE, Kinney ER, Kuhn S, Lee K, Lorenzon W, Lung A, Makins NC, Margaziotis DJ, McKeown RD, Milner RG, Mueller B, Napolitano J, Nelson J, O'Neill TG, Papavassiliou V V, Petratos GG, Potterveld DH, Rock SE, Spengos M, Szalata ZM, Tao LH, van Bibber K, Wasson DA, White JL, and Zeidman B

Published
1995
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44. Exclusive electron scattering from deuterium at high momentum transfer.

Author

Bulten HJ, Anthony PL, Arnold RG, Arrington J, Beise EJ, Belz E, van Bibber K, Bosted PE, van den Brand JF, Chapman MS, Coulter KP, Dietrich FS, Ent R, Epstein M, Filippone BW, Gao H, Gearhart RA, Geesaman DF, Hansen J, Holt RJ, Jackson HE, Jones CE, Keppel CE, Kinney E, Kuhn SE, Lee K, Lorenzon W, Lung A, Makins NC, Margaziotis DJ, McKeown RD, Milner RG, Mueller B, Napolitano J, Nelson J, O'Neill TG, Papavassiliou V V, Petratos GG, Potterveld DH, Rock SE, Spengos M, Szalata ZM, Tao LH, White JL, and Zeidman B

Published
1995
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45. Two-Body Photodisintegration of the Deuteron up to 2.8 GeV.

Author

Belz JE, Potterveld DH, Anthony P, Arnold RG, Arrington J, Beck D, Beise EJ, Bosted PE, Bulten H, Chapman MS, Coulter KP, Dietrich F, Ent R, Epstein M, Filippone BW, Gao H, Gearhart RA, Geesaman DF, Hansen J, Holt RJ, Jackson HE, Jones CE, Keppel CE, Kinney ER, Kuhn S, Lee K, Lorenzon W, Lung A, Makins NC, Margaziotis DJ, McKeown RD, Meziani ZE, Milner RG, Mueller B, Napolitano J, Nelson J, O'Neill TG, Papavassiliou V V, Petratos GG, Rock SE, Segel RE, Spengos M, Szalata ZM, Tao LH, van Bibber K, van den Brand JF, White JL, and Zeidman B

Published
1995
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46. Momentum transfer dependence of nuclear transparency from the quasielastic 12C(e,e'p) reaction.

Author

Makins NC, Ent R, Chapman MS, Hansen J, Lee K, Milner RG, Nelson J, Arnold RG, Bosted PE, Keppel CE, Lung A, Rock SE, Spengos M, Szalata ZM, Tao LH, White JL, Coulter KP, Geesaman DF, Holt RJ, Jackson HE, Papavassiliou V V, Potterveld DH, Zeidman B, Arrington J, Beise EJ, Belz E, Filippone BW, Gao H, Lorenzon W, Mueller B, McKeown RD, O'Neill TG, Epstein M, Margaziotis DJ, Napolitano J, Kinney E, Anthony PL, van Bibber K, Dietrich FS, Gearhart RA, Patratos GG, Kuhn SE, van den Brand JF, Bulten H, and Jones CE

Published
1994
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