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1. Probing for high-momentum protons in He4 via the He4(e,e′p)X reactions

Author

Iqbal, S, Benmokhtar, F, Ivanov, M, See, N, Aniol, K, Higinbotham, DW, Boyd, C, Gadsby, A, Goodwill, JS, Finton, D, Boyer, A, Gilad, S, Saha, A, Udias, JM, Ye, Z, Solvignon, P, Aguilera, P, Ahmed, Z, Albataineh, H, Allada, K, Anderson, B, Anez, D, Annand, J, Arrington, J, Averett, T, Baghdasaryan, H, Bai, X, Beck, A, Beck, S, Bellini, V, Camsonne, A, Chen, C, Chen, J-P, Chirapatpimol, K, Cisbani, E, Dalton, MM, Daniel, A, Day, D, Deconinck, W, Defurne, M, Flay, D, Fomin, N, Friend, M, Frullani, S, Fuchey, E, Garibaldi, F, Gaskell, D, Gilman, R, Glamazdin, S, Gu, C, Guèye, P, Hanretty, C, Hansen, J-O, Shabestari, M Hashemi, Huang, M, Jin, G, Kalantarians, N, Kang, H, Kelleher, A, Korover, I, LeRose, J, Leckey, J, Lindgren, R, Long, E, Mammei, J, Margaziotis, DJ, Markowitz, P, Meekins, D, Meziani, Z, Michaels, R, Mihovilovic, M, Muangma, N, Camacho, C Munoz, Norum, B, Nuruzzaman, Pan, K, Phillips, S, Piasetzky, E, Pomerantz, I, Posik, M, Punjabi, V, Qian, X, Qiang, Y, Qiu, X, Reimer, PE, Rakhman, A, Riordan, S, Ron, G, Rondon-Aramayo, O, Selvy, L, Shahinyan, A, Shneor, R, Sirca, S, Slifer, K, Sparveris, N, Subedi, R, Sulkosky, V, Wang, D, Watson, JW, and Weinstein, LB

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

Experimental cross sections for the He4(e,e′p)X reactions in the missing energy range from 0.017 to 0.022 GeV and up to a missing momentum of 0.632 GeV/c at xB=1.24 and Q2=2 (GeV/c)2 are reported. The data are compared to relativistic distorted-wave impulse approximation calculations for the He4(e,e′p)H3 channel. Significantly more events are observed for pm≥0.45 GeV/c than are predicted by the theoretical model, and striking fluctuations in the ratio of data to the theoretical model around pm=0.3GeV/c are possible signals of initial-state multinucleon correlations.

Published
2022

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

Author

Nguyen, D, Ye, Z, Aguilera, P, Ahmed, Z, Albataineh, H, Allada, K, Anderson, B, Anez, D, Aniol, K, Annand, J, Arrington, J, Averett, T, Baghdasaryan, H, Bai, X, Beck, A, Beck, S, Bellini, V, Benmokhtar, F, Camsonne, A, Chen, C, Chen, JP, Chirapatpimol, K, Cisbani, E, Dalton, MM, Daniel, A, Day, D, Deconinck, W, Defurne, M, Flay, D, Fomin, N, Friend, M, Frullani, S, Fuchey, E, Garibaldi, F, Gaskell, D, Gilad, S, Gilman, R, Glamazdin, S, Gu, C, Guèye, P, Hanretty, C, Hansen, JO, Shabestari, MH, Higinbotham, DW, Huang, M, Iqbal, S, Jin, G, Kalantarians, N, Kang, H, Kelleher, A, Korover, I, Lerose, J, Leckey, J, Li, S, Lindgren, R, Long, E, Mammei, J, Margaziotis, DJ, Markowitz, P, Meekins, D, Meziani, ZE, Michaels, R, Mihovilovic, M, Muangma, N, Camacho, CM, Norum, BE, Nuruzzaman, Pan, K, Phillips, S, Piasetzky, E, Pomerantz, I, Posik, M, Punjabi, V, Qian, X, Qiang, Y, Qiu, X, Reimer, PE, Rakhman, A, Riordan, S, Ron, G, Rondon-Aramayo, O, Saha, A, Selvy, L, Shahinyan, A, Shneor, R, Širca, S, Slifer, K, Solvignon, P, Sparveris, N, Subedi, R, Sulkosky, V, Wang, D, Watson, JW, Weinstein, LB, Wojtsekhowski, B, Wood, SA, Yaron, I, Zhan, X, Zhang, J, and Zhang, YW

Subjects
nucl-ex
Abstract

Short-range correlations (SRCs) have been identified as being responsible for the high-momentum tail of the nucleon momentum distribution, n(k). Hard, short-range interactions of nucleon pairs generate the high-momentum tail and imprint a universal character on n(k) for all nuclei at large momentum. Triple coincidence experiments have shown a strong dominance of np pairs, but these measurements involve large final-state interactions. This paper presents the results from Jefferson Lab experiment E08014 which measured inclusive electron scattering cross section from Ca isotopes. By comparing the inclusive cross section from Ca48 to Ca40 in a kinematic region dominated by SRCs we provide a new way to study the isospin structure of SRCs.

Published
2020

3. 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

4. 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

5. 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

6. Probing for high momentum protons in $^4$He via the $^4He(e,e'p)X$ reaction

Author

Iqbal, S, Benmokhtar, F, Ivanov, M, See, N, Aniol, K, Higinbotham, DW, Boyd, C, Gadsby, A, Gilad, S, Saha, A, Udias, JM, Goodwill, JS, Finton, D, Boyer, A, Ye, Z, Solvignon, P, Aguilera, P, Ahmed, Z, Albataineh, H, Allada, K, Anderson, B, Anez, D, Annand, J, Arrington, J, Averett, T, Baghdasaryan, H, Bai, X, Beck, A, Beck, S, Bellini, V, Camsonne, A, Chen, C, Chen, J-P, Chirapatpimol, K, Cisbani, E, Dalton, MM, Daniel, A, Day, D, Deconinck, W, Defurne, M, Flay, D, Fomin, N, Friend, M, Frullani, S, Fuchey, E, Garibaldi, F, Gaskell, D, Gilman, R, Glamazdin, S, Gu, C, Gueye, P, Hanretty, C, Hansen, J-O, Shabestari, M Hashemi, Huang, M, Jin, G, Kalantarians, N, Kang, H, Kelleher, A, Korover, I, LeRose, J, Leckey, J, Lindgren, R, Long, E, Mammei, J, Margaziotis, DJ, Markowitz, P, Meekins, D, Meziani, Z, Michaels, R, Mihovilovic, M, Muangma, N, Camacho, C Munoz, Norum, B, Nuruzzaman, Nuruzzaman, Pan, K, Phillips, S, Piasetzky, E, Pomerantz, I, Posik, M, Punjabi, V, Qian, X, Qiang, Y, Qiu, X, Reimer, PE, Rakhman, A, Riordan, S, Ron, G, Rondon-Aramayo, O, Selvy, L, Shahinyan, A, Shneor, R, Sirca, S, Slifer, K, Sparveris, N, Subedi, R, Sulkosky, V, Wang, D, Watson, JW, and Weinstein, LB

Subjects
nucl-ex
Abstract

Experimental cross sections for the $^4He(e,e'p)X$ reaction up to a missingmomentum of 0.632 GeV/$c$ at $x_B=1.24$ and $Q^2$=2(GeV/$c$)$^2$ are reported.The data are compared to Relativistic Distorted Wave ImpulseApproximation(RDWIA) calculations for $^4He(e,e'p)^3H$ channel. Significantlymore events in the triton mass region are measured for $p_{m}$$>$0.45 GeV/$c$than are predicted by the theoretical model, suggesting that the effects ofinitial-state multi-nucleon correlations are stronger than expected by theRDWIA model.

Published
2019

7. Technical supplement to “Polarization transfer observables in elastic electron-proton scattering at Q 2 = 2 . 5 , 5 . 2 , 6 . 8 and 8 . 5 GeV 2 ”

Author

Puckett, AJR, Brash, EJ, Jones, MK, Luo, W, Meziane, M, Pentchev, L, Perdrisat, CF, Punjabi, V, Wesselmann, FR, Afanasev, A, Ahmidouch, A, Albayrak, I, Aniol, KA, Arrington, J, Asaturyan, A, Baghdasaryan, H, Benmokhtar, F, Bertozzi, W, Bimbot, L, Bosted, P, Boeglin, W, Butuceanu, C, Carter, P, Chernenko, S, Christy, ME, Cornejo, JC, Covrig, S, Danagoulian, S, Daniel, A, Davidenko, A, Day, D, Dhamija, S, Dutta, D, Ent, R, Frullani, S, Fenker, H, Frlez, E, Garibaldi, F, Gaskell, D, Gilad, S, Gilman, R, Goncharenko, Y, Hafidi, K, Hamilton, D, Higinbotham, DW, Hinton, W, Horn, T, Hu, B, Huang, J, Huber, GM, Jensen, E, Keppel, C, Khandaker, M, King, P, Kirillov, D, Kohl, M, Kravtsov, V, Kumbartzki, G, Li, Y, Mamyan, V, Margaziotis, DJ, Marsh, A, Matulenko, Y, Maxwell, J, Mbianda, G, Meekins, D, Melnik, Y, Miller, J, Mkrtchyan, A, Mkrtchyan, H, Moffit, B, Moreno, O, Mulholland, J, Narayan, A, Nedev, S, Nuruzzaman, Piasetzky, E, Pierce, W, Piskunov, NM, Prok, Y, Ransome, RD, Razin, DS, Reimer, P, Reinhold, J, Rondon, O, Shabestari, M, Shahinyan, A, Shestermanov, K, Širca, S, Sitnik, I, Smykov, L, Smith, G, Solovyev, L, Solvignon, P, Subedi, R, Tomasi-Gustafsson, E, Vasiliev, A, Veilleux, M, Wojtsekhowski, BB, and Wood, S

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Proton form factors, Magnetic spectrometer, Electromagnetic calorimeter, Proton polarimeter, Polarization transfer method, Spin transport, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences, Nuclear & Particles Physics, Nuclear and plasma physics
Abstract

The GEp-III and GEp-2γ experiments, carried out in Jefferson Lab's Hall C from 2007–2008, consisted of measurements of polarization transfer in elastic electron–proton scattering at momentum transfers of Q2=2.5,5.2,6.8, and 8.54 GeV 2. These measurements were carried out to improve knowledge of the proton electromagnetic form factor ratio R=μpGEp∕GMp at large values of Q2 and to search for effects beyond the Born approximation in polarization transfer observables at Q2=2.5GeV2. The final results of both experiments were reported in a recent archival publication. A full reanalysis of the data from both experiments was carried out in order to reduce the systematic and, for the GEp-2γ experiment, statistical uncertainties. This technical note provides additional details of the final analysis omitted from the main publication, including the final evaluation of the systematic uncertainties.

Published
2018

8. Technical supplement to “Polarization transfer observables in elastic electron-proton scattering at Q2=2.5,5.2,6.8 and 8.5GeV2”

Author

Puckett, AJR, Brash, EJ, Jones, MK, Luo, W, Meziane, M, Pentchev, L, Perdrisat, CF, Punjabi, V, Wesselmann, FR, Afanasev, A, Ahmidouch, A, Albayrak, I, Aniol, KA, Arrington, J, Asaturyan, A, Baghdasaryan, H, Benmokhtar, F, Bertozzi, W, Bimbot, L, Bosted, P, Boeglin, W, Butuceanu, C, Carter, P, Chernenko, S, Christy, ME, Cornejo, JC, Covrig, S, Danagoulian, S, Daniel, A, Davidenko, A, Day, D, Dhamija, S, Dutta, D, Ent, R, Frullani, S, Fenker, H, Frlez, E, Garibaldi, F, Gaskell, D, Gilad, S, Gilman, R, Goncharenko, Y, Hafidi, K, Hamilton, D, Higinbotham, DW, Hinton, W, Horn, T, Hu, B, Huang, J, Huber, GM, Jensen, E, Keppel, C, Khandaker, M, King, P, Kirillov, D, Kohl, M, Kravtsov, V, Kumbartzki, G, Li, Y, Mamyan, V, Margaziotis, DJ, Marsh, A, Matulenko, Y, Maxwell, J, Mbianda, G, Meekins, D, Melnik, Y, Miller, J, Mkrtchyan, A, Mkrtchyan, H, Moffit, B, Moreno, O, Mulholland, J, Narayan, A, Nedev, S, Nuruzzaman, Piasetzky, E, Pierce, W, Piskunov, NM, Prok, Y, Ransome, RD, Razin, DS, Reimer, P, Reinhold, J, Rondon, O, Shabestari, M, Shahinyan, A, Shestermanov, K, Širca, S, Sitnik, I, Smykov, L, Smith, G, Solovyev, L, Solvignon, P, Subedi, R, Tomasi-Gustafsson, E, Vasiliev, A, Veilleux, M, Wojtsekhowski, BB, and Wood, S

Subjects
Proton form factors, Magnetic spectrometer, Electromagnetic calorimeter, Proton polarimeter, Polarization transfer method, Spin transport, Nuclear & Particles Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences
Abstract

The GEp-III and GEp-2γ experiments, carried out in Jefferson Lab's Hall C from 2007–2008, consisted of measurements of polarization transfer in elastic electron–proton scattering at momentum transfers of Q2=2.5,5.2,6.8, and 8.54 GeV 2. These measurements were carried out to improve knowledge of the proton electromagnetic form factor ratio R=μpGEp∕GMp at large values of Q2 and to search for effects beyond the Born approximation in polarization transfer observables at Q2=2.5GeV2. The final results of both experiments were reported in a recent archival publication. A full reanalysis of the data from both experiments was carried out in order to reduce the systematic and, for the GEp-2γ experiment, statistical uncertainties. This technical note provides additional details of the final analysis omitted from the main publication, including the final evaluation of the systematic uncertainties.

Published
2018

9. Erratum: Polarization transfer observables in elastic electron-proton scattering at Q2=2.5, 5.2, 6.8, and 8.5 GeV2 (Physical Review C (2017) 96 (055203) DOI: 10.1103/PhysRevC.96.055203)

Author

Puckett, AJR, Brash, EJ, Jones, MK, Luo, W, Meziane, M, Pentchev, L, Perdrisat, CF, Punjabi, V, Wesselmann, FR, Afanasev, A, Ahmidouch, A, Albayrak, I, Aniol, KA, Arrington, J, Asaturyan, A, Baghdasaryan, H, Benmokhtar, F, Bertozzi, W, Bimbot, L, Bosted, P, Boeglin, W, Butuceanu, C, Carter, P, Chernenko, S, Christy, ME, Commisso, M, Cornejo, JC, Covrig, S, Danagoulian, S, Daniel, A, Davidenko, A, Day, D, Dhamija, S, Dutta, D, Ent, R, Frullani, S, Fenker, H, Frlez, E, Garibaldi, F, Gaskell, D, Gilad, S, Gilman, R, Goncharenko, Y, Hafidi, K, Hamilton, D, Higinbotham, DW, Hinton, W, Horn, T, Hu, B, Huang, J, Huber, GM, Jensen, E, Keppel, C, Khandaker, M, King, P, Kirillov, D, Kohl, M, Kravtsov, V, Kumbartzki, G, Li, Y, Mamyan, V, Margaziotis, DJ, Marsh, A, Matulenko, Y, Maxwell, J, Mbianda, G, Meekins, D, Melnik, Y, Miller, J, Mkrtchyan, A, Mkrtchyan, H, Moffit, B, Moreno, O, Mulholland, J, Narayan, A, Nedev, S, Nuruzzaman, Piasetzky, E, Pierce, W, Piskunov, NM, Prok, Y, Ransome, RD, Razin, DS, Reimer, P, Reinhold, J, Rondon, O, Shabestari, M, Shahinyan, A, Shestermanov, K, Širca, S, Sitnik, I, Smykov, L, Smith, G, Solovyev, L, Solvignon, P, Subedi, R, Tomasi-Gustafsson, E, Vasiliev, A, Veilleux, M, and Wojtsekhowski, BB

Abstract

Subsequent to the release of our original paper, we discovered in the context of preparing our technical supplement [1] for journal publication that a typographical error had existed in the text file that the analysis program used to construct the beam polarization "database" for both the original analysis, published in Ref. [2], and our final analysis. The electron-beam polarization P e and the analyzing power A y cancel exactly in the ratio R , which is proportional to the ratio P t / P l of the transferred polarization components. On the other hand, the extraction of the relative e dependence of P l / P Born l relies on knowledge of the beam polarization. As such, data taking was interrupted roughly every two days during the GEp - 2 ? experiment to perform invasive measurements of the beam polarization using the Hall C Moller polarimeter [3]. The run range affected by the typographical error was entirely contained within the data collected at Q 2 = 2.5 GeV 2 with a beam energy of E e = 3.680 GeV during January 2008. The data from this configuration were combined with the data collected at E e = 3.548 GeV due to the nearly complete overlap of these two settings in terms of Q 2 and e acceptance. It is worth remarking that this typographical error went unnoticed for so long because it only affected a small fraction of the data (less than half of the combined data for ? e ? = 0.790 ) and the difference between the actually assigned beam polarization and the polarization that should have been assigned was comparable in magnitude to the point-to-point systematic uncertainty of the measurement itself. As such, its effect did not show up in various diagnostic plots and statistical tests, such as the time stability of the extracted P l / P Born l ratio. The data for both E e = 3.548 and E e = 3.680 GeV were reprocessed using the corrected beam polarizations to determine the effect of the typographical error on the combined physics results at ? e ? = 0.790 . Because the value of P e cancels in the ratio R , changes in the assumed beam polarization can only affect the results for R via statistical fluctuations due to changes in the relative weighting of different run ranges in the unbinned maximum-likelihood estimators for R . These effects are negligible on the scale of both the statistical and the systematic uncertainties of the data. More noticeable changes are expected in the ratio P l / P Born l since the extracted value of P l is inversely proportional to the assumed value of P e . Table I shows the effect of the corrected beam polarization database on the polarization transfer observables for the combined data for the ? e ? = 0.790 setting, the only measurement affected by the typographical error. The analyzing power did not need to be recalibrated since it was determined using the ? e ? = 0.153 data, which were not affected by the typographical error. As expected, the change in the ratio R is negligible. The value of P Born l , which is computed event by event from the global fit described in the Appendix of the original paper and does not depend on P e , is also unchanged. The magnitudes of P t , P l , and P l / P Born l are reduced by a common multiplicative factor, reflecting the fact that the beam polarization had been underestimated for the run range affected by the typographical error. The most important result of the corrected analysis is that the ratio P l / P Born l has decreased by 0.0024 from 1.0167 to 1.0143, a change comparable in magnitude to the statistical uncertainty but small compared to the total and point-to-point systematic uncertainties. The P l / P Born l result for the original publication [2] would be reduced by the same multiplicative factor as the final result. The physics conclusions of both publications are not materially changed by this correction. (Table Presented). (Figure Presented).

Published
2018

10. Erratum: Polarization transfer observables in elastic electron-proton scattering at Q2=2.5, 5.2, 6.8, and 8.5GeV2 [Phys. Rev. C 96, 055203 (2017)]

Author

Puckett, AJR, Brash, EJ, Jones, MK, Luo, W, Meziane, M, Pentchev, L, Perdrisat, CF, Punjabi, V, Wesselmann, FR, Afanasev, A, Ahmidouch, A, Albayrak, I, Aniol, KA, Arrington, J, Asaturyan, A, Baghdasaryan, H, Benmokhtar, F, Bertozzi, W, Bimbot, L, Bosted, P, Boeglin, W, Butuceanu, C, Carter, P, Chernenko, S, Christy, ME, Commisso, M, Cornejo, JC, Covrig, S, Danagoulian, S, Daniel, A, Davidenko, A, Day, D, Dhamija, S, Dutta, D, Ent, R, Frullani, S, Fenker, H, Frlez, E, Garibaldi, F, Gaskell, D, Gilad, S, Gilman, R, Goncharenko, Y, Hafidi, K, Hamilton, D, Higinbotham, DW, Hinton, W, Horn, T, Hu, B, Huang, J, Huber, GM, Jensen, E, Keppel, C, Khandaker, M, King, P, Kirillov, D, Kohl, M, Kravtsov, V, Kumbartzki, G, Li, Y, Mamyan, V, Margaziotis, DJ, Marsh, A, Matulenko, Y, Maxwell, J, Mbianda, G, Meekins, D, Melnik, Y, Miller, J, Mkrtchyan, A, Mkrtchyan, H, Moffit, B, Moreno, O, Mulholland, J, Narayan, A, Nedev, S, Nuruzzaman, Piasetzky, E, Pierce, W, Piskunov, NM, Prok, Y, Ransome, RD, Razin, DS, Reimer, P, Reinhold, J, Rondon, O, Shabestari, M, Shahinyan, A, Shestermanov, K, Širca, S, Sitnik, I, Smykov, L, Smith, G, Solovyev, L, Solvignon, P, Subedi, R, Tomasi-Gustafsson, E, Vasiliev, A, Veilleux, M, and Wojtsekhowski, BB

Subjects
Physical Sciences, Classical Physics, Nuclear and plasma physics
Abstract

Subsequent to the release of our original paper, we discovered in the context of preparing our technical supplement [1] for journal publication that a typographical error had existed in the text file that the analysis program used to construct the beam polarization "database" for both the original analysis, published in Ref. [2], and our final analysis. The electron-beam polarization P e and the analyzing power A y cancel exactly in the ratio R , which is proportional to the ratio P t / P l of the transferred polarization components. On the other hand, the extraction of the relative e dependence of P l / P Born l relies on knowledge of the beam polarization. As such, data taking was interrupted roughly every two days during the GEp - 2 ? experiment to perform invasive measurements of the beam polarization using the Hall C Moller polarimeter [3]. The run range affected by the typographical error was entirely contained within the data collected at Q 2 = 2.5 GeV 2 with a beam energy of E e = 3.680 GeV during January 2008. The data from this configuration were combined with the data collected at E e = 3.548 GeV due to the nearly complete overlap of these two settings in terms of Q 2 and e acceptance. It is worth remarking that this typographical error went unnoticed for so long because it only affected a small fraction of the data (less than half of the combined data for ? e ? = 0.790 ) and the difference between the actually assigned beam polarization and the polarization that should have been assigned was comparable in magnitude to the point-to-point systematic uncertainty of the measurement itself. As such, its effect did not show up in various diagnostic plots and statistical tests, such as the time stability of the extracted P l / P Born l ratio. The data for both E e = 3.548 and E e = 3.680 GeV were reprocessed using the corrected beam polarizations to determine the effect of the typographical error on the combined physics results at ? e ? = 0.790 . Because the value of P e cancels in the ratio R , changes in the assumed beam polarization can only affect the results for R via statistical fluctuations due to changes in the relative weighting of different run ranges in the unbinned maximum-likelihood estimators for R . These effects are negligible on the scale of both the statistical and the systematic uncertainties of the data. More noticeable changes are expected in the ratio P l / P Born l since the extracted value of P l is inversely proportional to the assumed value of P e . Table I shows the effect of the corrected beam polarization database on the polarization transfer observables for the combined data for the ? e ? = 0.790 setting, the only measurement affected by the typographical error. The analyzing power did not need to be recalibrated since it was determined using the ? e ? = 0.153 data, which were not affected by the typographical error. As expected, the change in the ratio R is negligible. The value of P Born l , which is computed event by event from the global fit described in the Appendix of the original paper and does not depend on P e , is also unchanged. The magnitudes of P t , P l , and P l / P Born l are reduced by a common multiplicative factor, reflecting the fact that the beam polarization had been underestimated for the run range affected by the typographical error. The most important result of the corrected analysis is that the ratio P l / P Born l has decreased by 0.0024 from 1.0167 to 1.0143, a change comparable in magnitude to the statistical uncertainty but small compared to the total and point-to-point systematic uncertainties. The P l / P Born l result for the original publication [2] would be reduced by the same multiplicative factor as the final result. The physics conclusions of both publications are not materially changed by this correction. (Table Presented). (Figure Presented).

Published
2018

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

Author

Ye, Z, Solvignon, P, Nguyen, D, Aguilera, P, Ahmed, Z, Albataineh, H, Allada, K, Anderson, B, Anez, D, Aniol, K, Annand, J, Arrington, J, Averett, T, Baghdasaryan, H, Bai, X, Beck, A, Beck, S, Bellini, V, Benmokhtar, F, Camsonne, A, Chen, C, Chen, JP, Chirapatpimol, K, Cisbani, E, Dalton, MM, Daniel, A, Day, D, Deconinck, W, Defurne, M, Flay, D, Fomin, N, Friend, M, Frullani, S, Fuchey, E, Garibaldi, F, Gaskell, D, Gilad, S, Gilman, R, Glamazdin, S, Gu, C, Guèye, P, Hanretty, C, Hansen, JO, Shabestari, MH, Higinbotham, DW, Huang, M, Iqbal, S, Jin, G, Kalantarians, N, Kang, H, Kelleher, A, Korover, I, Lerose, J, Leckey, J, Lindgren, R, Long, E, Mammei, J, Margaziotis, DJ, Markowitz, P, Meekins, D, Meziani, Z, Michaels, R, Mihovilovic, M, Muangma, N, Camacho, CM, Norum, B, Nuruzzaman, Pan, K, Phillips, S, Piasetzky, E, Pomerantz, I, Posik, M, Punjabi, V, Qian, X, Qiang, Y, Qiu, X, Reimer, PE, Rakhman, A, Riordan, S, Ron, G, Rondon-Aramayo, O, Saha, A, Selvy, L, Shahinyan, A, Shneor, R, Sirca, S, Slifer, K, Sparveris, N, Subedi, R, Sulkosky, V, Wang, D, Watson, JW, Weinstein, LB, Wojtsekhowski, B, Wood, SA, Yaron, I, Zhan, X, Zhang, J, Zhang, YW, and Zhao, B

Subjects
nucl-ex
Abstract

We present new data probing short-range correlations (SRCs) in nuclei through the measurement of electron scattering off high-momentum nucleons in nuclei. The inclusive He4/He3 cross section ratio is observed to be both x and Q2 independent for 1.52, our data support the hypothesis that a previous claim of three-nucleon correlation dominance was an artifact caused by the limited resolution of the measurement. While 3N-SRCs appear to have an important contribution, our data show that isolating 3N-SRCs is significantly more complicated than for 2N-SRCs.

Published
2018

12. 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

13. Publisher’s Note: JLab Measurements of the He3 Form Factors at Large Momentum Transfers [Phys. Rev. Lett. 119, 162501 (2017)]

Author

Camsonne, A, Katramatou, AT, Olson, M, Acha, A, Allada, K, Anderson, BD, Arrington, J, Baldwin, A, Chen, J-P, Choi, S, Chudakov, E, Cisbani, E, Craver, B, Decowski, P, Dutta, C, Folts, E, Frullani, S, Garibaldi, F, Gilman, R, Gomez, J, Hahn, B, Hansen, J-O, Higinbotham, DW, Holmstrom, T, Huang, J, Iodice, M, Jiang, X, Kelleher, A, Khrosinkova, E, Kievsky, A, Kuchina, E, Kumbartzki, G, Lee, B, LeRose, JJ, Lindgren, RA, Lott, G, Lu, H, Marcucci, LE, Margaziotis, DJ, Markowitz, P, Marrone, S, Meekins, D, Meziani, Z-E, Michaels, R, Moffit, B, Norum, B, Petratos, GG, Puckett, A, Qian, X, Rondon, O, Saha, A, Sawatzky, B, Segal, J, Shabestari, M, Shahinyan, A, Solvignon, P, Sparveris, N, Subedi, RR, Suleiman, R, Sulkosky, V, Urciuoli, GM, Viviani, M, Wang, Y, Wojtsekhowski, BB, Yan, X, Yao, H, Zhang, W-M, Zheng, X, and Zhu, L

Subjects
Quantum Physics, Physical Sciences, Jefferson Lab Hall A Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

This corrects the article DOI: 10.1103/PhysRevLett.119.162501.

Published
2017

14. Publisher's Note: JLab Measurements of the ^{3}He Form Factors at Large Momentum Transfers [Phys. Rev. Lett. 119, 162501 (2017)].

Author

Camsonne, A, Katramatou, AT, Olson, M, Acha, A, Allada, K, Anderson, BD, Arrington, J, Baldwin, A, Chen, J-P, Choi, S, Chudakov, E, Cisbani, E, Craver, B, Decowski, P, Dutta, C, Folts, E, Frullani, S, Garibaldi, F, Gilman, R, Gomez, J, Hahn, B, Hansen, J-O, Higinbotham, DW, Holmstrom, T, Huang, J, Iodice, M, Jiang, X, Kelleher, A, Khrosinkova, E, Kievsky, A, Kuchina, E, Kumbartzki, G, Lee, B, LeRose, JJ, Lindgren, RA, Lott, G, Lu, H, Marcucci, LE, Margaziotis, DJ, Markowitz, P, Marrone, S, Meekins, D, Meziani, Z-E, Michaels, R, Moffit, B, Norum, B, Petratos, GG, Puckett, A, Qian, X, Rondon, O, Saha, A, Sawatzky, B, Segal, J, Shabestari, M, Shahinyan, A, Solvignon, P, Sparveris, N, Subedi, RR, Suleiman, R, Sulkosky, V, Urciuoli, GM, Viviani, M, Wang, Y, Wojtsekhowski, BB, Yan, X, Yao, H, Zhang, W-M, Zheng, X, Zhu, L, and Jefferson Lab Hall A Collaboration

Subjects
Jefferson Lab Hall A Collaboration, General Physics, Mathematical Sciences, Physical Sciences, Engineering
Abstract

This corrects the article DOI: 10.1103/PhysRevLett.119.162501.

Published
2017

15. Polarization transfer observables in elastic electron-proton scattering at Q2=2.5, 5.2, 6.8, and 8.5 GeV2 POLARIZATION TRANSFER OBSERVABLES in ELASTIC ... A. J. R. PUCKETT et al.

Author

Puckett, AJR, Brash, EJ, Jones, MK, Luo, W, Meziane, M, Pentchev, L, Perdrisat, CF, Punjabi, V, Wesselmann, FR, Afanasev, A, Ahmidouch, A, Albayrak, I, Aniol, KA, Arrington, J, Asaturyan, A, Baghdasaryan, H, Benmokhtar, F, Bertozzi, W, Bimbot, L, Bosted, P, Boeglin, W, Butuceanu, C, Carter, P, Chernenko, S, Christy, ME, Commisso, M, Cornejo, JC, Covrig, S, Danagoulian, S, Daniel, A, Davidenko, A, Day, D, Dhamija, S, Dutta, D, Ent, R, Frullani, S, Fenker, H, Frlez, E, Garibaldi, F, Gaskell, D, Gilad, S, Gilman, R, Goncharenko, Y, Hafidi, K, Hamilton, D, Higinbotham, DW, Hinton, W, Horn, T, Hu, B, Huang, J, Huber, GM, Jensen, E, Keppel, C, Khandaker, M, King, P, Kirillov, D, Kohl, M, Kravtsov, V, Kumbartzki, G, Li, Y, Mamyan, V, Margaziotis, DJ, Marsh, A, Matulenko, Y, Maxwell, J, Mbianda, G, Meekins, D, Melnik, Y, Miller, J, Mkrtchyan, A, Mkrtchyan, H, Moffit, B, Moreno, O, Mulholland, J, Narayan, A, Nedev, S, Nuruzzaman, Piasetzky, E, Pierce, W, Piskunov, NM, Prok, Y, Ransome, RD, Razin, DS, Reimer, P, Reinhold, J, Rondon, O, Shabestari, M, Shahinyan, A, Shestermanov, K, Širca, S, Sitnik, I, Smykov, L, Smith, G, Solovyev, L, Solvignon, P, Subedi, R, Tomasi-Gustafsson, E, Vasiliev, A, Veilleux, M, and Wojtsekhowski, BB

Abstract

Background: Interest in the behavior of nucleon electromagnetic form factors at large momentum transfers has steadily increased since the discovery, using polarization observables, of the rapid decrease of the ratio GEp/GMp of the proton's electric and magnetic form factors for momentum transfers Q21 GeV2, in strong disagreement with previous extractions of this ratio using the traditional Rosenbluth separation technique. Purpose: The GEp-III and GEp-2γ experiments were carried out in Jefferson Laboratory's (JLab's) Hall C from 2007 to 2008, to extend the knowledge of GEp/GMp to the highest practically achievable Q2 given the maximum beam energy of 6 GeV and to search for effects beyond the Born approximation in polarization transfer observables of elastic ∫ - p scattering. This article provides an expanded description of the common experimental apparatus and data analysis procedures, and reports the results of a final reanalysis of the data from both experiments, including the previously unpublished results of the full-acceptance dataset of the GEp-2γ experiment. Methods: Polarization transfer observables in elastic ∫ - p→∫ - scattering were measured at central Q2 values of 2.5, 5.2, 6.8, and 8.54 GeV2. At Q2=2.5GeV2, data were obtained for central values of the virtual photon polarization parameter ϵ of 0.149, 0.632, and 0.783. The Hall C High Momentum Spectrometer detected and measured the polarization of protons recoiling elastically from collisions of JLab's polarized electron beam with a liquid hydrogen target. A large-acceptance electromagnetic calorimeter detected the elastically scattered electrons in coincidence to suppress inelastic backgrounds. Results: The final GEp-III data are largely unchanged relative to the originally published results. The statistical uncertainties of the final GEp-2γ data are significantly reduced at ϵ=0.632 and 0.783 relative to the original publication. Conclusions: The final GEp-III results show that the decrease with Q2 of GEp/GMp continues to Q2=8.5GeV2, but at a slowing rate relative to the approximately linear decrease observed in earlier Hall A measurements. At Q2=8.5GeV2, GEp/GMp remains positive but is consistent with zero. At Q2=2.5GeV2, GEp/GMp derived from the polarization component ratio R-Pt/P shows no statistically significant ϵ dependence, as expected in the Born approximation. On the other hand, the ratio P""/P""Born of the longitudinal polarization transfer component to its Born value shows an enhancement of roughly 1.7% at ϵ=0.783 relative to ϵ=0.149, with ≈2.2σ significance based on the total uncertainty, implying a similar effect in the transverse component Pt that cancels in the ratio R.

Published
2017

16. JLab Measurements of the He3 Form Factors at Large Momentum Transfers

Author

Camsonne, A, Katramatou, AT, Olson, M, Acha, A, Allada, K, Anderson, BD, Arrington, J, Baldwin, A, Chen, J-P, Choi, S, Chudakov, E, Cisbani, E, Craver, B, Decowski, P, Dutta, C, Folts, E, Frullani, S, Garibaldi, F, Gilman, R, Gomez, J, Hahn, B, Hansen, J-O, Higinbotham, DW, Holmstrom, T, Huang, J, Iodice, M, Jiang, X, Kelleher, A, Khrosinkova, E, Kievsky, A, Kuchina, E, Kumbartzki, G, Lee, B, LeRose, JJ, Lindgren, RA, Lott, G, Lu, H, Marcucci, LE, Margaziotis, DJ, Markowitz, P, Marrone, S, Meekins, D, Meziani, Z-E, Michaels, R, Moffit, B, Norum, B, Petratos, GG, Puckett, A, Qian, X, Rondon, O, Saha, A, Sawatzky, B, Segal, J, Shabestari, M, Shahinyan, A, Solvignon, P, Sparveris, N, Subedi, RR, Suleiman, R, Sulkosky, V, Urciuoli, GM, Viviani, M, Wang, Y, Wojtsekhowski, BB, Yan, X, Yao, H, Zhang, W-M, Zheng, X, and Zhu, L

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

The charge and magnetic form factors, F_{C} and F_{M}, respectively, of ^{3}He are extracted in the kinematic range 25  fm^{-2}≤Q^{2}≤61  fm^{-2} from elastic electron scattering by detecting ^{3}He recoil nuclei and scattered electrons in coincidence with the two High Resolution Spectrometers of the Hall A Facility at Jefferson Lab. The measurements find evidence for the existence of a second diffraction minimum for the magnetic form factor at Q^{2}=49.3  fm^{-2} and for the charge form factor at Q^{2}=62.0  fm^{-2}. Both minima are predicted to exist in the Q^{2} range accessible by this Jefferson Lab experiment. The data are in qualitative agreement with theoretical calculations based on realistic interactions and accurate methods to solve the three-body nuclear problem.

Published
2017

17. JLab Measurements of the ^{3}He Form Factors at Large Momentum Transfers.

Author

Camsonne, A, Katramatou, AT, Olson, M, Acha, A, Allada, K, Anderson, BD, Arrington, J, Baldwin, A, Chen, J-P, Choi, S, Chudakov, E, Cisbani, E, Craver, B, Decowski, P, Dutta, C, Folts, E, Frullani, S, Garibaldi, F, Gilman, R, Gomez, J, Hahn, B, Hansen, J-O, Higinbotham, DW, Holmstrom, T, Huang, J, Iodice, M, Jiang, X, Kelleher, A, Khrosinkova, E, Kievsky, A, Kuchina, E, Kumbartzki, G, Lee, B, LeRose, JJ, Lindgren, RA, Lott, G, Lu, H, Marcucci, LE, Margaziotis, DJ, Markowitz, P, Marrone, S, Meekins, D, Meziani, Z-E, Michaels, R, Moffit, B, Norum, B, Petratos, GG, Puckett, A, Qian, X, Rondon, O, Saha, A, Sawatzky, B, Segal, J, Shabestari, M, Shahinyan, A, Solvignon, P, Sparveris, N, Subedi, RR, Suleiman, R, Sulkosky, V, Urciuoli, GM, Viviani, M, Wang, Y, Wojtsekhowski, BB, Yan, X, Yao, H, Zhang, W-M, Zheng, X, Zhu, L, and Jefferson Lab Hall A Collaboration

Subjects
Jefferson Lab Hall A Collaboration, Heart Disease, Cardiovascular, General Physics, Mathematical Sciences, Physical Sciences, Engineering
Abstract

The charge and magnetic form factors, F_{C} and F_{M}, respectively, of ^{3}He are extracted in the kinematic range 25  fm^{-2}≤Q^{2}≤61  fm^{-2} from elastic electron scattering by detecting ^{3}He recoil nuclei and scattered electrons in coincidence with the two High Resolution Spectrometers of the Hall A Facility at Jefferson Lab. The measurements find evidence for the existence of a second diffraction minimum for the magnetic form factor at Q^{2}=49.3  fm^{-2} and for the charge form factor at Q^{2}=62.0  fm^{-2}. Both minima are predicted to exist in the Q^{2} range accessible by this Jefferson Lab experiment. The data are in qualitative agreement with theoretical calculations based on realistic interactions and accurate methods to solve the three-body nuclear problem.

Published
2017

18. Electroexcitation of the Δ+(1232) at low momentum transfer

Author

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

Subjects
CMR, Pion electroproduction, Nucleon deformation, Nuclear & Particles Physics, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

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

Published
2016

19. Polarization transfer observables in elastic electron-proton scattering at Q2=2.5, 5.2, 6.8, and 8.5 GeV2

Author

Puckett, AJR, Brash, EJ, Jones, MK, Luo, W, Meziane, M, Pentchev, L, Perdrisat, CF, Punjabi, V, Wesselmann, FR, Afanasev, A, Ahmidouch, A, Albayrak, I, Aniol, KA, Arrington, J, Asaturyan, A, Baghdasaryan, H, Benmokhtar, F, Bertozzi, W, Bimbot, L, Bosted, P, Boeglin, W, Butuceanu, C, Carter, P, Chernenko, S, Christy, ME, Commisso, M, Cornejo, JC, Covrig, S, Danagoulian, S, Daniel, A, Davidenko, A, Day, D, Dhamija, S, Dutta, D, Ent, R, Frullani, S, Fenker, H, Frlez, E, Garibaldi, F, Gaskell, D, Gilad, S, Gilman, R, Goncharenko, Y, Hafidi, K, Hamilton, D, Higinbotham, DW, Hinton, W, Horn, T, Hu, B, Huang, J, Huber, GM, Jensen, E, Keppel, C, Khandaker, M, King, P, Kirillov, D, Kohl, M, Kravtsov, V, Kumbartzki, G, Li, Y, Mamyan, V, Margaziotis, DJ, Marsh, A, Matulenko, Y, Maxwell, J, Mbianda, G, Meekins, D, Melnik, Y, Miller, J, Mkrtchyan, A, Mkrtchyan, H, Moffit, B, Moreno, O, Mulholland, J, Narayan, A, Nedev, S, Nuruzzaman, Piasetzky, E, Pierce, W, Piskunov, NM, Prok, Y, Ransome, RD, Razin, DS, Reimer, P, Reinhold, J, Rondon, O, Shabestari, M, Shahinyan, A, Shestermanov, K, Širca, S, Sitnik, I, Smykov, L, Smith, G, Solovyev, L, Solvignon, P, Subedi, R, Tomasi-Gustafsson, E, Vasiliev, A, Veilleux, M, and Wojtsekhowski, BB

Subjects
Particle and Plasma Physics, Molecular, Nuclear, Atomic, Nuclear & Particles Physics
Abstract

Background: Interest in the behavior of nucleon electromagnetic form factors at large momentum transfers has steadily increased since the discovery, using polarization observables, of the rapid decrease of the ratio GEp/GMp of the proton's electric and magnetic form factors for momentum transfers Q21 GeV2, in strong disagreement with previous extractions of this ratio using the traditional Rosenbluth separation technique. Purpose: The GEp-III and GEp-2γ experiments were carried out in Jefferson Laboratory's (JLab's) Hall C from 2007 to 2008, to extend the knowledge of GEp/GMp to the highest practically achievable Q2 given the maximum beam energy of 6 GeV and to search for effects beyond the Born approximation in polarization transfer observables of elastic ∫ - p scattering. This article provides an expanded description of the common experimental apparatus and data analysis procedures, and reports the results of a final reanalysis of the data from both experiments, including the previously unpublished results of the full-acceptance dataset of the GEp-2γ experiment. Methods: Polarization transfer observables in elastic ∫ - p→∫ - scattering were measured at central Q2 values of 2.5, 5.2, 6.8, and 8.54 GeV2. At Q2=2.5GeV2, data were obtained for central values of the virtual photon polarization parameter ϵ of 0.149, 0.632, and 0.783. The Hall C High Momentum Spectrometer detected and measured the polarization of protons recoiling elastically from collisions of JLab's polarized electron beam with a liquid hydrogen target. A large-acceptance electromagnetic calorimeter detected the elastically scattered electrons in coincidence to suppress inelastic backgrounds. Results: The final GEp-III data are largely unchanged relative to the originally published results. The statistical uncertainties of the final GEp-2γ data are significantly reduced at ϵ=0.632 and 0.783 relative to the original publication. Conclusions: The final GEp-III results show that the decrease with Q2 of GEp/GMp continues to Q2=8.5GeV2, but at a slowing rate relative to the approximately linear decrease observed in earlier Hall A measurements. At Q2=8.5GeV2, GEp/GMp remains positive but is consistent with zero. At Q2=2.5GeV2, GEp/GMp derived from the polarization component ratio R-Pt/P shows no statistically significant ϵ dependence, as expected in the Born approximation. On the other hand, the ratio P""/P""Born of the longitudinal polarization transfer component to its Born value shows an enhancement of roughly 1.7% at ϵ=0.783 relative to ϵ=0.149, with ≈2.2σ significance based on the total uncertainty, implying a similar effect in the transverse component Pt that cancels in the ratio R.

Published
2017

20. Probing the Repulsive Core of the Nucleon-Nucleon Interaction via the He-4(e,e'pN) Triple-Coincidence Reaction

Author

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

Published
2014

21. Measurement of the Neutron Radius of Pb-208 through Parity Violation in Electron Scattering

Author

Abrahamyan, S, Ahmed, Z, Albataineh, H, Aniol, K, Armstrong, Ds, Armstrong, W, Averett, T, Babineau, B, Barbieri, A, Bellini, Vincenzo, Beminiwattha, R, Benesch, J, Benmokhtar, F, Bielarski, T, Boeglin, W, Camsonne, A, Canan, M, Carter, P, Cates, Gd, Chen, C, Chen, Jp, Hen, O, Cusanno, F, Dalton, Mm, De, Le, R, de Jager, K, Deconinck, W, Decowski, P, Deng, X, Deur, A, Dutta, D, Etile, A, Flay, D, Franklin, Gb, Friend, M, Frullani, S, Fuchey, E, Garibaldi, F, Gasser, E, Gilman, R, Giusa, A, Glamazdin, A, Gomez, J, Grames, J, Gu, C, Hansen, O, Hansknecht, J, Higinbotham, Dw, Holmes, Rs, Holmstrom, T, Horowitz, Cj, Hoskins, J, Huang, J, Hyde, Ce, Itard, F, Jen, Cm, Jensen, E, Jin, G, Johnston, S, Kelleher, A, Kliakhandler, K, King, Pm, Kowalski, S, Kumar, Ks, Leacock, J, Leckey, J, Lee, Jh, Lerose, Jj, Lindgren, R, Liyanage, N, Lubinsky, N, Mammei, J, Mammoliti, Francesco, Margaziotis, Dj, Markowitz, P, Mccreary, A, Mcnulty, D, Mercado, L, Meziani, Ze, Michaels, Rw, Mihovilovic, M, Muangma, N, Munoz Camacho, C, Nanda, S, Nelyubin, V, Nuruzzaman, N, Oh, Y, Palmer, A, Parno, D, Paschke, Kd, Phillips, Sk, Poelker, B, Pomatsalyuk, R, Posik, M, Puckett, Ajr, Quinn, B, Rakhman, A, Reimer, Pe, Riordan, S, Rogan, P, Ron, G, Russo, Giuseppe, Saenboonruang, K, Saha, A, Sawatzky, B, Shahinyan, A, Silwal, R, Sirca, S, Slifer, K, Solvignon, P, Souder, Pa, Sperduto, Ml, Subedi, R, Suleiman, R, Sulkosky, V, Sutera, CONCETTA MARIA, Tobias, Wa, Troth, W, Urciuoli, Gm, Waidyawansa, B, Wang, D, Wexler, J, Wilson, R, Wojtsekhowski, B, Yan, X, Yao, H, Ye, Y, Ye, Z, Yim, V, Zana, L, Zhan, X, Zhang, J, Zhang, Y, Zheng, X, and PREX Collaboration, Zhu P.

Subjects
ELECTRON-SCATTERING, NUCLEI, DENSITIES
Published
2012

22. Virtual Compton scattering and the generalized polarizabilities of the proton at Q²=0.92 and 1.76 GeV²

Author

Fonvieille, H, Laveissiere, G, Degrande, N, Jaminion, S, Jutier, C, Todor, L, Di Salvo, R, Van Hoorebeke, Luc, Alexa, LC, Anderson, BD, Aniol, KA, Arundell, K, Audit, G, Auerbach, L, Baker, FT, Baylac, M, Berthot, J, Bertin, PY, Bertozzi, W, Bimbot, L, Boeglin, WU, Brash, EJ, Breton, V, Breuer, H, Burtin, E, Calarco, JR, Cardman, LS, Cavata, C, Chang, CC, Chen, JP, Chudakov, E, Cisbani, E, Dale, DS, de Jager, CW, De Leo, R, Deur, A, d'Hose, N, Dodge, GE, Domingo, JJ, Elouadrhiri, L, Epstein, MB, Ewell, LA, Finn, JM, Fissum, KG, Fournier, G, Frois, B, Frullani, S, Furget, C, Gao, H, Gao, J, Garibaldi, F, Gasparian, A, Gilad, S, Gilman, R, Glamazdin, A, Glashausser, C, Gomez, J, Gorbenko, V, Grenier, P, Guichon, PAM, Hansen, JO, Holmes, R, Holtrop, M, Howell, C, Huber, GM, Hyde, CE, Incerti, S, Iodice, M, Jardillier, J, Jones, MK, Kahl, W, Kato, S, Katramatou, AT, Kelly, JJ, Kerhoas, S, Ketikyan, A, Khayat, M, Kino, K, Kox, S, Kramer, LH, Kumar, KS, Kumbartzki, G, Kuss, M, Leone, A, LeRose, JJ, Liang, M, Lindgren, RA, Liyanage, N, Lolos, GJ, Lourie, RW, Madey, R, Maeda, K, Malov, S, Manley, DM, Marchand, C, Marchand, D, Margaziotis, DJ, Markowitz, P, Marroncle, J, Martino, J, McCormick, K, McIntyre, J, Mehrabyan, S, Merchez, F, Meziani, ZE, Michaels, R, Miller, GW, Mougey, JY, Nanda, SK, Neyret, D, Offermann, EAJM, Papandreou, Z, Pasquini, B, Perdrisat, CF, Perrino, R, Petratos, GG, Platchkov, S, Pomatsalyuk, R, Prout, DL, Punjabi, VA, Pussieux, T, Quemener, G, Ransome, RD, Ravel, O, Real, JS, Renard, F, Roblin, Y, Rowntree, D, Rutledge, G, Rutt, PM, Saha, A, Saito, T, Sarty, AJ, Serdarevic, A, Smith, T, Smirnov, G, Soldi, K, Sorokin, P, Souder, PA, Suleiman, R, Templon, JA, Terasawa, T, Tieulent, R, Tomasi-Gustaffson, E, Tsubota, H, Ueno, H, Ulmer, PE, Urciuoli, GM, Vanderhaeghen, M, Van der Meer, RLJ, Van de Vyver, R, Vernin, P, Vlahovic, B, Voskanyan, H, Voutier, E, Watson, JW, Weinstein, LB, Wijesooriya, K, Wilson, R, Wojtsekhowski, BB, Zainea, DG, Zhang, WM, Zhao, J, and Zhou, ZL

Subjects
Physics and Astronomy, LINEAR SIGMA-MODEL, NUCLEON POLARIZABILITIES, AMPLITUDE, ELECTROPRODUCTION, LOW-ENERGY, Nuclear Experiment, CHIRAL PERTURBATION-THEORY, REAL, THRESHOLD
Abstract

Virtual Compton scattering (VCS) on the proton has been studied at the Jefferson Laboratory using the exclusive photon electroproduction reaction ep -> ep gamma. This paper gives a detailed account of the analysis which has led to the determination of the structure functions P-LL - P-TT/epsilon and P-LT and the electric and magnetic generalized polarizabilities (GPs) alpha(E) (Q(2)) and beta(M) (Q(2)) at values of the four-momentum transfer squared Q(2) = 0.92 and 1.76 GeV2. These data, together with the results of VCS experiments at lower momenta, help building a coherent picture of the electric and magnetic GPs of the proton over the full measured Q(2) range and point to their nontrivial behavior.

Published
2012

23. Cross sections and Rosenbluth separations in H1(e,e′K +)Λ up to Q2=2.35GeV2

Author

Coman, M, Markowitz, P, Aniol, KA, Baker, K, Boeglin, WU, Breuer, H, Bydẑovský, P, Camsonne, A, Cha, J, Chang, CC, Chant, N, Chen, J-P, Chudakov, EA, Cisbani, E, Cole, L, Cusanno, F, De Jager, CW, De Leo, R, Deur, AP, Dieterich, S, Dohrmann, F, Dutta, D, Ent, R, Filoti, O, Fissum, K, Frullani, S, Garibaldi, F, Gayou, O, Gilman, F, Gomez, J, Gueye, P, Hansen, JO, Higinbotham, DW, Hinton, W, Horn, T, Hu, B, Huber, GM, Iodice, M, Jackson, C, Jiang, X, Jones, M, Kanda, K, Keppel, C, King, P, Klein, F, Kozlov, K, Kramer, K, Kramer, L, Lagamba, L, Lerose, JJ, Liyanage, N, Margaziotis, DJ, Marrone, S, McCormick, K, Michaels, RW, Mitchell, J, Miyoshi, T, Nanda, S, Palomba, M, Pattichio, V, Perdrisat, CF, Piasetzky, E, Punjabi, VA, Raue, B, Reinhold, J, Reitz, B, Roche, RE, Roos, P, Saha, A, Sarty, AJ, Sato, Y, Airca, S, Sotona, M, Tang, L, Ueno, H, Ulmer, PE, Urciuoli, GM, Uzzle, A, Vacheret, A, Wang, K, Wijesooriya, K, Wojtsekhowski, B, Wood, S, Yaron, I, Zheng, X, and Zhu, L

Subjects
Nuclear Experiment
Abstract

The kaon electroproduction reaction H1(e,e′K +)Λ was studied as a function of the virtual-photon four-momentum, Q2, total energy, W, and momentum transfer, t, for different values of the virtual-photon polarization parameter. Data were taken at electron beam energies ranging from 3.40 to 5.75GeV. The center of mass cross section was determined for twenty-one kinematics corresponding to Q2 of 1.90 and 2.35GeV2, and the longitudinal, σL, and transverse, σT, cross sections were separated using the Rosenbluth technique at fixed W and t. The separated cross sections reveal a flat energy dependence at forward kaon angles not satisfactorily described by existing electroproduction models. Influence of the kaon pole on the cross sections was investigated by adopting an off-shell form factor in the Regge model, which better describes the observed energy dependence of σT and σL. © 2010 The American Physical Society.

Published
2010

24. Constraints on the nucleon strange form factors at Q(2)similar to 0.1 GeV2

Author

Aniol, KA, Armstrong, DS, Averett, T, Benaoum, H, Bertin, PY, Burtin, E, Cahoon, J, Gates, GD, Chang, CC, Chao, YC, Chen, JP, Choi, SH, Chudakov, E, Craver, B, Cusanno, F, Decowski, P, Deepa, D, Ferdi, C, Feuerbach, RJ, Finn, JM, Frullani, S, Fuoti, K, Garibaldi, F, Gilman, R, Glamazdin, A, Gorbenko, V, Grames, JM, Hansknecht, J, Higinbotham, DW, Holmes, R, Holmstrom, T, Humensky, TB, Ibrahim, H, de Jager, CW, Jiang, X, Kaufman, LJ, Kelleher, A, Kolarkar, A, Kowalski, S, Kumar, KS, Lambert, D, LaViolette, P, LeRose, J, Lhuillier, D, Liyanage, N, Margaziotis, DJ, Mazouz, M, McCormick, K, Meekins, DG, Meziani, ZE, Michaels, R, Moffit, B, Monaghan, P, Munoz-Camacho, C, Nanda, S, Nelyubin, V, Neyret, D, Paschke, KD, Poelker, M, Pomatsalyuk, R, Qiang, Y, Reitz, B, Roche, J, Saha, A, Singh, J, Snyder, R, Souder, PA, Stutzman, M, Subedi, R, Suleiman, R, Sulkosky, V, Tobias, WA, Urciuoli, GM, Vacheret, A, Voutier, E, Wang, K, Wilson, R, Wojtsekhowski, B, and Zheng, X

Published
2006

25. Parity-violating electron scattering from 4He and the strange electric form factor of the nucleon

Author

Aniol, KA, Armstrong, DS, Averett, T, Benaoum, H, Bertin, PY, Burtin, E, Cahoon, J, Cates, GD, Chang, CC, Chao, YC, Chen, JP, Choi, S, Chudakov, E, Craver, B, Cusanno, F, Decowski, P, Deepa, D, Ferdi, C, Feuerbach, RJ, Finn, JM, Frullani, S, Fuoti, K, Garibaldi, F, Gilman, R, Glamazdin, A, Gorbenko, V, Grames, JM, Hansknecht, J, Higinbotham, DW, Holmes, R, Holmstrom, T, Humensky, TB, Ibrahim, H, de Jager, CW, Jiang, X, Kaufman, LJ, Kelleher, A, Kolarkar, A, Kowalski, S, Kumar, KS, Lambert, D, LaViolette, P, LeRose, J, Lhuillier, D, Liyanage, N, Margaziotis, DJ, Mazouz, M, McCormick, K, Meekins, DG, Meziani, ZE, Michaels, R, Moffit, B, Monaghan, P, Munoz-Camacho, C, Nanda, S, Nelyubin, V, Neyret, D, Paschke, KD, Poelker, M, Pomatsalyuk, R, Qiang, Y, Reitz, B, Roche, J, Saha, A, Singh, J, Snyder, R, Souder, PA, Subedi, R, Suleiman, R, Sulkosky, V, Tobias, WA, Urciuoli, GM, Vacheret, A, Voutier, E, Wang, K, Wilson, R, Wojtsekhowski, B, and Zheng, X

Subjects
High Energy Physics::Experiment, Nuclear Experiment
Abstract

We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from 4He at an average scattering angle = 5.7 degrees and a four-momentum transfer Q2 = 0.091 GeV2 . From these data, for the first time, the strange electric form factor of the nucleon G(E)s can be isolated. The measured asymmetry of A(PV) = (6.72 +/- 0.84(stat) +/- 0.21(syst) x 10(-6) yields a value of G(E)s = -0.038 +/- 0.042(stat) +/- 0.010(syst), consistent with zero.

Published
2005

26. Recoil polarization for Delta excitation in pion electroproduction - art. no. 102002

Author

Kelly, JJ Roche, RE Chai, Z Jones, MK Gayou, O and Sarty, AJ Frullani, S Aniol, K Beise, EJ Benmokhtar, F and Bertozzi, W Boeglin, WU Botto, T Brash, EJ Breuer, H and Brown, E Burtin, E Calarco, JR Cavata, C Chang, CC and Chant, NS Chen, JP Coman, M Crovelli, D De Leo, R and Dieterich, S Escoffier, S Fissum, KG Garde, V and Garibaldi, F Georgakopoulus, S Gilad, S Gilman, R and Glashausser, C Hansen, JO Higinbotham, DW Hotta, A and Huber, GM Ibrahim, H Iodice, M de Jager, CW Jiang, X and Klimenko, A Kozlov, A Kumbartzki, G Kuss, M Lagamba, L and Laveissiere, G LeRose, JJ Lindgren, RA Liyanage, N and Lolos, GJ Lourie, RW Margaziotis, DJ Marie, F Markowitz, P McAleer, S Meekins, D Michaels, R Milbrath, BD and Mitchell, J Nappa, J Neyret, D Perdrisat, CF Potokar, M and Punjabi, VA Pussieux, T Ransome, RD Roos, PG and Rvachev, M Saha, A Sirca, S Suleiman, R Strauch, S and Templon, JA Todor, L Ulmer, PE Urciuoli, GM Weinstein, LB Wijesooriya, K Wojtsekhowski, B Zheng, X Zhu, L and Jefferson Lab E91011 Collaboration Hall A Collaboration

Abstract

We measured angular distributions of recoil-polarization response functions for neutral pion electroproduction for W=1.23 GeV at Q(2)=1.0 (GeV/c)(2), obtaining 14 separated response functions plus 2 Rosenbluth combinations; of these, 12 have been observed for the first time. Dynamical models do not describe quantities governed by imaginary parts of interference products well, indicating the need for adjusting magnitudes and phases for nonresonant amplitudes. We performed a nearly model-independent multipole analysis and obtained values for Re (S1+/M1+)= -(6.84 +/- 0.15)% and Re (E1+/M1+)= -(2.91 +/- 0.19)% that are distinctly different from those from the traditional Legendre analysis based upon M1+ dominance and l(pi)

Published
2005

27. Measurement of recoil proton polarizations in the electrodisintegration of deuterium by polarized electrons

Author

Barkhuff, DH Armstrong, CS Bertozzi, W Chen, JP Dale, D and Dodson, G Dow, KA Epstein, MB Farkhondeh, M Finn, JM and Gilad, S Jones, MK Joo, K Kelly, JJ Kowalski, S and Liu, D Lourie, RW McIntyre, JI Madey, R Margaziotis, DJ and Markowitz, P Mertz, C Milbrath, BD Mitchell, J and Mukhopadhyay, S Perdrisat, CF Punjabi, V Qin, L Rutt, PM and Sarty, AJ Tieger, D Tschalaer, C Turchinetz, W and Ulmer, PE Van Verst, SP Vellidis, C Warren, G Weinstein, LB Woo, RJ

Subjects
Nuclear Theory, Nuclear Experiment
Abstract

In order to test modem theories of two-nucleon bound and scattering states, we have measured the spin polarization of ejectile protons in the electrodisintegration reaction d((e) over right arrow, e’(p) over right arrow)n. Compared with spin-averaged observations, these observables offer the potential of enhanced sensitivity to details of the reaction process. The experiment was carried out in quasielastic kinematics (q(mu)q(mu)= -2m(p) omega= -0.38GeV(2)/c(2)). Protons were detected at two angles corresponding to neutron recoil momenta p(r) of 0 and 100MeV/c. Full nonrelativistic calculations of the polarization transfer components s(l) and s(t), including leading order relativistic contributions, describe our measurements well, but calculations of the induced polarization s(n) at p(r) = 100 MeV/c underpredict the experimental result. (C) 1999 Published by Elsevier Science B.V. All rights reserved.

Published
1999

28. Quasielastic C-12(e,e ' p) reaction at high momentum transfer

Author

Morrison, JH, Baghaei, H, Bertozzi, W, Gilad, S, Glickman, J, Hyde-Wright, CE, Kalantar-Nayestanaki, N, Lourie, RW, Penn, S, Ulmer, PE, Weinstein, LB, Cottman, BH, Ghedira, L, Winhold, EJ, Calarco, J.R., Wise, J, Boberg, P, Chang, CC, Zhang, D, Aniol, K, Epstein, MB, Margaziotis, DJ, Finn, JM, Perdrisat, C, Punjabi, P., and Research unit Nuclear & Hadron Physics

Subjects
SEPARATED RESPONSE FUNCTIONS, COULOMB SUM-RULE, E,E'P REACTION, NUCLEI, INELASTIC ELECTRON-SCATTERING, LONGITUDINAL RESPONSE, C-12, Nuclear Theory, TRANSVERSE, POTENTIALS, Nuclear Experiment, CROSS-SECTIONS
Abstract

We measured the C-12(e,e'p) cross section as a function of missing energy in parallel kinematics for (q,omega)=(970 MeV/c, 330 MeV) and (990 MeV/c, 475 MeV). At omega=475 MeV, at the maximum of the quasielastic peak, there is a large continuum (E-m>50 MeV) cross section extending out to the deepest missing energy measured, amounting to almost 50% of the measured cross section. The ratio of data to distorted-wave impulse approximation (DWIA) calculation is 0.4 for both p and s shells. At omega = 330 MeV, well below the maximum of the quasielastic peak,the continuum cross section is much smaller and the ratio of data to DWIA calculation is 0.85 for the p shell and 1.0 for the s shell. We infer that one or more mechanisms that increase with omega transform some of the single-nucleon knockouts into a multinucleon knockout, decreasing the valence knockout cross section and increasing the continuum cross section. [S0556-2813(99)00701-3].

Published
1999

29. Out-of-plane measurements of the fifth response function of the exclusive electronuclear response

Author

Dolfini, SM Alarcon, RO Arenhovel, H Beck, R Bernstein, AM Bertozzi, W Boeglin, W Boffi, S Comfort, JR Dale, D Dodson, G Dow, K Epstein, MB Farkhondeh, M Gilad, S Gorgen, J Holtrop, M Jordan, D Kim, W Kowalski, S and Laszewski, R Mandeville, J Margaziotis, DJ Martinez, D and McIlvain, T Miskimen, R Papanicolas, C Radici, M and Tieger, D Turchinetz, W Vellidis, CE Weinstein, L and Williamson, S

Abstract

The first measurements of f(LT)’ known as the fifth response function, have been made for the H-2((e) over right arrow, e’p) and C-12((3) over right arrow, e’p) reactions. This response is directly related to the imaginary part of the interference between the transverse and longitudinal nuclear electromagnetic currents. Its observation requires longitudinally polarized electron beams and out-of-plane detection, the latter made possible by the newly developed out-of-plane spectrometer system. The initial measurements were made by using a 560-MeV polarized electron beam and quasielastic kinematics at Q(2) = 3.3 fm(-2). The development of the methodology for out-of-plane physics, and the analysis of the data from the initial experiments are described in detail. The measured fifth response and the related asymmetry in the coincidence cross section are in agreement, albeit with large statistical errors, with the theoretical predictions. Future extensions of the out-of-plane program are also discussed. [S0556-2813(99)02812-5].

Published
1999

30. Measurement of the induced proton polarization P-n in the C-12(e,e '(p)over-right-arrow) reaction

Author

Woo, RJ Barkhuff, DH Bertozzi, W Chen, JP Dale, D and Dodson, G Dow, KA Epstein, MB Farkhondeh, M Finn, JM and Gilad, S Jones, MK Joo, K Kelly, JJ Kowalski, S and Lourie, RW Madey, R Margaziotis, DJ Markowitz, P and McIntyre, JI Mertz, C Milbrath, BD Mitchell, J and Perdrisat, CF Punjabi, V Rutt, PM Sarty, AJ Tieger, D and Tschalaer, C Turchinetz, W Ulmer, PE Van Verst, SP and Vellidis, C Warren, GA Weinstein, L

Subjects
Nuclear Theory, Nuclear Experiment
Abstract

The first measurements of the induced proton polarization P-n for the C-12(e,e’(p) over right arrow) reaction are reported. The experiment was performed at quasifree kinematics for energy and momentum transfer (w, q) approximate to (294 MeV, 756 MeV/c) and sampled a missing momentum range of 0-250 MeV/c. The induced polarization arises from final-state interactions and for these kinematics is dominated by the real part of the spin-orbit optical potential. The distorted-wave impulse approximation provides good agreement with data fur the 1p(3/2) shelf. The data for the continuum suggest that both the 1s(1/2) shell and underlying l > 1 configurations contribute.

Published
1998

31. The longitudinal and transverse response of the He-4(e, e ' p) reaction in the dip region

Author

Alexandre Kozlov, Aniol, Ka, Bartsch, P., Baumann, D., Bertozzi, W., Bohm, R., Bohinc, K., Chen, Jp, Dale, D., Dennis, L., Derber, S., Ding, M., Distler, Mo, Dragovitsch, P., Ewald, I., Fissum, Kg, Florizone, Rej, Friedrich, J., Friedrich, Jm, Geiges, R., Gilad, S., Jennewein, P., Kahrau, M., Kohl, M., Krygier, Kw, Liesenfeld, A., Margaziotis, Dj, Merkel, H., Merle, P., Muller, U., Neuhausen, R., Pospischil, T., Riccardi, G., Roche, R., Rosner, G., Rowntree, D., Sarty, Aj, Schmieden, H., Sirca, S., Templon, Ja, Thompson, Mn, Wagner, A., Walcher, T., Weis, M., Zhao, J., and Zhou, Z.

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

Author

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

Abstract

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

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

Author

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

Abstract

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

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

Author

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

Abstract

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

Published
2016
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35. Polarization Transfer in Wide-Angle Compton Scattering and Single-Pion Photoproduction from the Proton.

Author

Fanelli C, Cisbani E, Hamilton DJ, Salmé G, Wojtsekhowski B, Ahmidouch A, Annand JR, Baghdasaryan H, Beaufait J, Bosted P, Brash EJ, Butuceanu C, Carter P, Christy E, Chudakov E, Danagoulian S, Day D, Degtyarenko P, Ent R, Fenker H, Fowler M, Frlez E, Gaskell D, Gilman R, Horn T, Huber GM, de Jager CW, Jensen E, Jones MK, Kelleher A, Keppel C, Khandaker M, Kohl M, Kumbartzki G, Lassiter S, Li Y, Lindgren R, Lovelace H, Luo W, Mack D, Mamyan V, Margaziotis DJ, Markowitz P, Maxwell J, Mbianda G, Meekins D, Meziane M, Miller J, Mkrtchyan A, Mkrtchyan H, Mulholland J, Nelyubin V, Pentchev L, Perdrisat CF, Piasetzky E, Prok Y, Puckett AJ, Punjabi V, Shabestari M, Shahinyan A, Slifer K, Smith G, Solvignon P, Subedi R, Wesselmann FR, Wood S, Ye Z, and Zheng X

Abstract

Wide-angle exclusive Compton scattering and single-pion photoproduction from the proton have been investigated via measurement of the polarization transfer from a circularly polarized photon beam to the recoil proton. The wide-angle Compton scattering polarization transfer was analyzed at an incident photon energy of 3.7 GeV at a proton scattering angle of θ_{cm}^{p}=70°. The longitudinal transfer K_{LL}, measured to be 0.645±0.059±0.048, where the first error is statistical and the second is systematic, has the same sign as predicted for the reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton. However, the observed value is ~3 times larger than predicted by the generalized-parton-distribution-based calculations, which indicates a significant unknown contribution to the scattering amplitude.

Published
2015
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36. Measurement of the target-normal single-spin asymmetry in deep-inelastic scattering from the reaction (3)He(↑)(e,e')X.

Author

Katich J, Qian X, Zhao YX, Allada K, Aniol K, Annand JR, Averett T, Benmokhtar F, Bertozzi W, Bradshaw PC, Bosted P, Camsonne A, Canan M, Cates GD, Chen C, Chen JP, Chen W, Chirapatpimol K, Chudakov E, Cisbani E, Cornejo JC, Cusanno F, Dalton MM, Deconinck W, de Jager CW, De Leo R, Deng X, Deur A, Ding H, Dolph PA, Dutta C, Dutta D, El Fassi L, Frullani S, Gao H, Garibaldi F, Gaskell D, Gilad S, Gilman R, Glamazdin O, Golge S, Guo L, Hamilton D, Hansen O, Higinbotham DW, Holmstrom T, Huang J, Huang M, Ibrahim HF, Iodice M, Jiang X, Jin G, Jones MK, Kelleher A, Kim W, Kolarkar A, Korsch W, LeRose JJ, Li X, Li Y, Lindgren R, Liyanage N, Long E, Lu HJ, Margaziotis DJ, Markowitz P, Marrone S, McNulty D, Meziani ZE, Michaels R, Moffit B, Muñoz Camacho C, Nanda S, Narayan A, Nelyubin V, Norum B, Oh Y, Osipenko M, Parno D, Peng JC, Phillips SK, Posik M, Puckett AJ, Qiang Y, Rakhman A, Ransome RD, Riordan S, Saha A, Sawatzky B, Schulte E, Shahinyan A, Shabestari MH, Širca S, Stepanyan S, Subedi R, Sulkosky V, Tang LG, Tobias A, Urciuoli GM, Vilardi I, Wang K, Wang Y, Wojtsekhowski B, Yan X, Yao H, Ye Y, Ye Z, Yuan L, Zhan X, Zhang Y, Zhang YW, Zhao B, Zheng X, Zhu L, Zhu X, and Zong X

Abstract

We report the first measurement of the target-normal single-spin asymmetry in deep-inelastic scattering from the inclusive reaction 3)He(↑)(e,e')X on a polarized (3)He gas target. Assuming time-reversal invariance, this asymmetry is strictly zero in the Born approximation but can be nonzero if two-photon-exchange contributions are included. The experiment, conducted at Jefferson Lab using a 5.89 GeV electron beam, covers a range of 1.72  GeV, which is nonzero at the 2.89σ level. Our measured asymmetry agrees both in sign and magnitude with a two-photon-exchange model prediction that uses input from the Sivers transverse momentum distribution obtained from semi-inclusive deep-inelastic scattering.

Published
2014
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37. Probing the repulsive core of the nucleon-nucleon interaction via the (4)He(e,e'pN) triple-coincidence reaction.

Author

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

Abstract

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

Published
2014
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38. 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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39. JLab measurement of the 4He charge form factor at large momentum transfers.

Author

Camsonne A, Katramatou AT, Olson M, Sparveris N, Acha A, Allada K, Anderson BD, Arrington J, Baldwin A, Chen JP, Choi S, Chudakov E, Cisbani E, Craver B, Decowski P, Dutta C, Folts E, Frullani S, Garibaldi F, Gilman R, Gomez J, Hahn B, Hansen JO, Higinbotham DW, Holmstrom T, Huang J, Iodice M, Jiang X, Kelleher A, Khrosinkova E, Kievsky A, Kuchina E, Kumbartzki G, Lee B, LeRose JJ, Lindgren RA, Lott G, Lu H, Marcucci LE, Margaziotis DJ, Markowitz P, Marrone S, Meekins D, Meziani ZE, Michaels R, Moffit B, Norum B, Petratos GG, Puckett A, Qian X, Rondon O, Saha A, Sawatzky B, Segal J, Shabestari M, Shahinyan A, Solvignon P, Subedi RR, Suleiman R, Sulkosky V, Urciuoli GM, Viviani M, Wang Y, Wojtsekhowski BB, Yan X, Yao H, Zhang WM, Zheng X, and Zhu L

Abstract

The charge form factor of 4He has been extracted in the range 29  fm(-2) ≤ Q2 ≤ 77  fm(-2) from elastic electron scattering, detecting 4He recoil nuclei and electrons in coincidence with the high resolution spectrometers of the Hall A Facility of Jefferson Lab. The measurements have uncovered a second diffraction minimum for the form factor, which was predicted in the Q2 range of this experiment. The data are in qualitative agreement with theoretical calculations based on realistic interactions and accurate methods to solve the few-body problem.

Published
2014
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40. Measurements of parity-violating asymmetries in electron-deuteron scattering in the nucleon resonance region.

Author

Wang D, Pan K, Subedi R, Deng X, Ahmed Z, Allada K, Aniol KA, Armstrong DS, Arrington J, Bellini V, Beminiwattha R, Benesch J, Benmokhtar F, Camsonne A, Canan M, Cates GD, Chen JP, Chudakov E, Cisbani E, Dalton MM, de Jager CW, De Leo R, Deconinck W, Deur A, Dutta C, El Fassi L, Flay D, Franklin GB, Friend M, Frullani S, Garibaldi F, Giusa A, Glamazdin A, Golge S, Grimm K, Hafidi K, Hansen O, Higinbotham DW, Holmes R, Holmstrom T, Holt RJ, Huang J, Hyde CE, Jen CM, Jones D, Kang H, King P, Kowalski S, Kumar KS, Lee JH, LeRose JJ, Liyanage N, Long E, McNulty D, Margaziotis DJ, Meddi F, Meekins DG, Mercado L, Meziani ZE, Michaels R, Mihovilovic M, Muangma N, Myers KE, Nanda S, Narayan A, Nelyubin V, Nuruzzaman, Oh Y, Parno D, Paschke KD, Phillips SK, Qian X, Qiang Y, Quinn B, Rakhman A, Reimer PE, Rider K, Riordan S, Roche J, Rubin J, Russo G, Saenboonruang K, Saha A, Sawatzky B, Shahinyan A, Silwal R, Sirca S, Souder PA, Suleiman R, Sulkosky V, Sutera CM, Tobias WA, Urciuoli GM, Waidyawansa B, Wojtsekhowski B, Ye L, Zhao B, and Zheng X

Abstract

We report on parity-violating asymmetries in the nucleon resonance region measured using inclusive inelastic scattering of 5-6 GeV longitudinally polarized electrons off an unpolarized deuterium target. These results are the first parity-violating asymmetry data in the resonance region beyond the Δ(1232). They provide a verification of quark-hadron duality-the equivalence of the quark- and hadron-based pictures of the nucleon-at the (10-15)% level in this electroweak observable, which is dominated by contributions from the nucleon electroweak γZ interference structure functions. In addition, the results provide constraints on nucleon resonance models relevant for calculating background corrections to elastic parity-violating electron scattering measurements.

Published
2013
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41. Polarization components in π0 photoproduction at photon energies up to 5.6 GeV.

Author

Luo W, Brash EJ, Gilman R, Jones MK, Meziane M, Pentchev L, Perdrisat CF, Puckett AJ, Punjabi V, Wesselmann FR, Ahmidouch A, Albayrak I, Aniol KA, Arrington J, Asaturyan A, Ates O, Baghdasaryan H, Benmokhtar F, Bertozzi W, Bimbot L, Bosted P, Boeglin W, Butuceanu C, Carter P, Chernenko S, Christy ME, Commisso M, Cornejo JC, Covrig S, Danagoulian S, Daniel A, Davidenko A, Day D, Dhamija S, Dutta D, Ent R, Frullani S, Fenker H, Frlez E, Garibaldi F, Gaskell D, Gilad S, Goncharenko Y, Hafidi K, Hamilton D, Higinbotham DW, Hinton W, Horn T, Hu B, Huang J, Huber GM, Jensen E, Kang H, Keppel C, Khandaker M, King P, Kirillov D, Kohl M, Kravtsov V, Kumbartzki G, Li Y, Mamyan V, Margaziotis DJ, Markowitz P, Marsh A, Matulenko Y, Maxwell J, Mbianda G, Meekins D, Melnik Y, Miller J, Mkrtchyan A, Mkrtchyan H, Moffit B, Moreno O, Mulholland J, Narayan A, Nuruzzaman, Nedev S, Piasetzky E, Pierce W, Piskunov NM, Prok Y, Ransome RD, Razin DS, Reimer PE, Reinhold J, Rondon O, Shabestari M, Shahinyan A, Shestermanov K, Širca S, Sitnik I, Smykov L, Smith G, Solovyev L, Solvignon P, Strakovsky II, Subedi R, Suleiman R, Tomasi-Gustafsson E, Vasiliev A, Veilleux M, Wood S, Ye Z, Zanevsky Y, Zhang X, Zhang Y, Zheng X, and Zhu L

Abstract

We present new data for the polarization observables of the final state proton in the (1)H(γ,p)π(0) reaction. These data can be used to test predictions based on hadron helicity conservation and perturbative QCD. These data have both small statistical and systematic uncertainties and were obtained with beam energies between 1.8 and 5.6 GeV and for π(0) scattering angles larger than 75° in the center-of-mass frame. The data extend the polarization measurements database for neutral pion photoproduction up to E(γ)=5.6 GeV. The results show a nonzero induced polarization above the resonance region. The polarization transfer components vary rapidly with the photon energy and π(0) scattering angle in the center-of-mass frame. This indicates that hadron helicity conservation does not hold and that the perturbative QCD limit is still not reached in the energy regime of this experiment.

Published
2012
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42. Measurement of the neutron radius of 208Pb through parity violation in electron scattering.

Author

Abrahamyan S, Ahmed Z, Albataineh H, Aniol K, Armstrong DS, Armstrong W, Averett T, Babineau B, Barbieri A, Bellini V, Beminiwattha R, Benesch J, Benmokhtar F, Bielarski T, Boeglin W, Camsonne A, Canan M, Carter P, Cates GD, Chen C, Chen JP, Hen O, Cusanno F, Dalton MM, De Leo R, de Jager K, Deconinck W, Decowski P, Deng X, Deur A, Dutta D, Etile A, Flay D, Franklin GB, Friend M, Frullani S, Fuchey E, Garibaldi F, Gasser E, Gilman R, Giusa A, Glamazdin A, Gomez J, Grames J, Gu C, Hansen O, Hansknecht J, Higinbotham DW, Holmes RS, Holmstrom T, Horowitz CJ, Hoskins J, Huang J, Hyde CE, Itard F, Jen CM, Jensen E, Jin G, Johnston S, Kelleher A, Kliakhandler K, King PM, Kowalski S, Kumar KS, Leacock J, Leckey J 4th, Lee JH, LeRose JJ, Lindgren R, Liyanage N, Lubinsky N, Mammei J, Mammoliti F, Margaziotis DJ, Markowitz P, McCreary A, McNulty D, Mercado L, Meziani ZE, Michaels RW, Mihovilovic M, Muangma N, Muñoz-Camacho C, Nanda S, Nelyubin V, Nuruzzaman N, Oh Y, Palmer A, Parno D, Paschke KD, Phillips SK, Poelker B, Pomatsalyuk R, Posik M, Puckett AJ, Quinn B, Rakhman A, Reimer PE, Riordan S, Rogan P, Ron G, Russo G, Saenboonruang K, Saha A, Sawatzky B, Shahinyan A, Silwal R, Sirca S, Slifer K, Solvignon P, Souder PA, Sperduto ML, Subedi R, Suleiman R, Sulkosky V, Sutera CM, Tobias WA, Troth W, Urciuoli GM, Waidyawansa B, Wang D, Wexler J, Wilson R, Wojtsekhowski B, Yan X, Yao H, Ye Y, Ye Z, Yim V, Zana L, Zhan X, Zhang J, Zhang Y, Zheng X, and Zhu P

Abstract

We report the first measurement of the parity-violating asymmetry A(PV) in the elastic scattering of polarized electrons from 208Pb. A(PV) is sensitive to the radius of the neutron distribution (R(n)). The result A(PV)=0.656±0.060(stat)±0.014(syst) ppm corresponds to a difference between the radii of the neutron and proton distributions R(n)-R(p)=0.33(-0.18)(+0.16) fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.

Published
2012
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43. Beam-target double-spin asymmetry A{LT} in charged pion production from deep inelastic scattering on a transversely polarized {3}He target at 1.4<Q{2}<2.7  GeV{2}.

Author

Huang J, Allada K, Dutta C, Katich J, Qian X, Wang Y, Zhang Y, Aniol K, Annand JR, Averett T, Benmokhtar F, Bertozzi W, Bradshaw PC, Bosted P, Camsonne A, Canan M, Cates GD, Chen C, Chen JP, Chen W, Chirapatpimol K, Chudakov E, Cisbani E, Cornejo JC, Cusanno F, Dalton MM, Deconinck W, de Jager CW, De Leo R, Deng X, Deur A, Ding H, Dolph PA, Dutta D, El Fassi L, Frullani S, Gao H, Garibaldi F, Gaskell D, Gilad S, Gilman R, Glamazdin O, Golge S, Guo L, Hamilton D, Hansen O, Higinbotham DW, Holmstrom T, Huang M, Ibrahim HF, Iodice M, Jiang X, Jin G, Jones MK, Kelleher A, Kim W, Kolarkar A, Korsch W, Lerose JJ, Li X, Li Y, Lindgren R, Liyanage N, Long E, Lu HJ, Margaziotis DJ, Markowitz P, Marrone S, McNulty D, Meziani ZE, Michaels R, Moffit B, Muñoz Camacho C, Nanda S, Narayan A, Nelyubin V, Norum B, Oh Y, Osipenko M, Parno D, Peng JC, Phillips SK, Posik M, Puckett AJ, Qiang Y, Rakhman A, Ransome RD, Riordan S, Saha A, Sawatzky B, Schulte E, Shahinyan A, Shabestari MH, Sirca S, Stepanyan S, Subedi R, Sulkosky V, Tang LG, Tobias A, Urciuoli GM, Vilardi I, Wang K, Wojtsekhowski B, Yan X, Yao H, Ye Y, Ye Z, Yuan L, Zhan X, Zhang YW, Zhao B, Zheng X, Zhu L, Zhu X, and Zong X

Abstract

We report the first measurement of the double-spin asymmetry A{LT} for charged pion electroproduction in semi-inclusive deep-inelastic electron scattering on a transversely polarized {3}He target. The kinematics focused on the valence quark region, 0.16

Published
2012
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44. Probing the high momentum component of the deuteron at high Q2.

Author

Boeglin WU, Coman L, Ambrozewicz P, Aniol K, Arrington J, Batigne G, Bosted P, Camsonne A, Chang G, Chen JP, Choi S, Deur A, Epstein M, Finn JM, Frullani S, Furget C, Garibaldi F, Gayou O, Gilman R, Hansen O, Hayes D, Higinbotham DW, Hinton W, Hyde C, Ibrahim H, de Jager CW, Jiang X, Jones MK, Kaufman LJ, Klein A, Kox S, Kramer L, Kumbartzki G, Laget JM, LeRose J, Lindgren R, Margaziotis DJ, Markowitz P, McCormick K, Meziani Z, Michaels R, Milbrath B, Mitchell J, Monaghan P, Moteabbed M, Moussiegt P, Nasseripour R, Paschke K, Perdrisat C, Piasetzky E, Punjabi V, Qattan IA, Quéméner G, Ransome RD, Raue B, Réal JS, Reinhold J, Reitz B, Roché R, Roedelbronn M, Saha A, Slifer K, Solvignon P, Sulkosky V, Ulmer PE, Voutier E, Weinstein LB, Wojtsekhowski B, and Zeier M

Abstract

The (2)H(e,e'p)n cross section at a momentum transfer of 3.5 (GeV/c)(2) was measured over a kinematical range that made it possible to study this reaction for a set of fixed missing momenta as a function of the neutron recoil angle θ(nq) and to extract missing momentum distributions for fixed values of θ(nq) up to 0.55  GeV/c. In the region of 35°≤θ(nq)≤45° recent calculations, which predict that final-state interactions are small, agree reasonably well with the experimental data. Therefore, these experimental reduced cross sections provide direct access to the high momentum component of the deuteron momentum distribution in exclusive deuteron electrodisintegration.

Published
2011
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45. Single spin asymmetries in charged pion production from semi-inclusive deep inelastic scattering on a transversely polarized 3He Target at Q2 = 1.4-2.7 GeV2.

Author

Qian X, Allada K, Dutta C, Huang J, Katich J, Wang Y, Zhang Y, Aniol K, Annand JR, Averett T, Benmokhtar F, Bertozzi W, Bradshaw PC, Bosted P, Camsonne A, Canan M, Cates GD, Chen C, Chen JP, Chen W, Chirapatpimol K, Chudakov E, Cisbani E, Cornejo JC, Cusanno F, Dalton MM, Deconinck W, de Jager CW, De Leo R, Deng X, Deur A, Ding H, Dolph PA, Dutta D, El Fassi L, Frullani S, Gao H, Garibaldi F, Gaskell D, Gilad S, Gilman R, Glamazdin O, Golge S, Guo L, Hamilton D, Hansen O, Higinbotham DW, Holmstrom T, Huang M, Ibrahim HF, Iodice M, Jiang X, Jin G, Jones MK, Kelleher A, Kim W, Kolarkar A, Korsch W, LeRose JJ, Li X, Li Y, Lindgren R, Liyanage N, Long E, Lu HJ, Margaziotis DJ, Markowitz P, Marrone S, McNulty D, Meziani ZE, Michaels R, Moffit B, Camacho CM, Nanda S, Narayan A, Nelyubin V, Norum B, Oh Y, Osipenko M, Parno D, Peng JC, Phillips SK, Posik M, Puckett AJ, Qiang Y, Rakhman A, Ransome RD, Riordan S, Saha A, Sawatzky B, Schulte E, Shahinyan A, Shabestari MH, Sirca S, Stepanyan S, Subedi R, Sulkosky V, Tang LG, Tobias A, Urciuoli GM, Vilardi I, Wang K, Wojtsekhowski B, Yan X, Yao H, Ye Y, Ye Z, Yuan L, Zhan X, Zhang YW, Zhao B, Zheng X, Zhu L, Zhu X, and Zong X

Abstract

We report the first measurement of target single spin asymmetries in the semi-inclusive (3)He(e,e'π(±))X reaction on a transversely polarized target. The experiment, conducted at Jefferson Lab using a 5.9 GeV electron beam, covers a range of 0.16 < x < 0.35 with 1.4 < Q(2) < 2.7 GeV(2). The Collins and Sivers moments were extracted from the azimuthal angular dependence of the measured asymmetries. The π(±) Collins moments for (3)He are consistent with zero, except for the π(+) moment at x = 0.35, which deviates from zero by 2.3σ. While the π(-) Sivers moments are consistent with zero, the π(+) Sivers moments favor negative values. The neutron results were extracted using the nucleon effective polarization and measured cross section ratios of proton to (3)He, and are largely consistent with the predictions of phenomenological fits and quark model calculations.

Published
2011
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46. Search for effects beyond the born approximation in polarization transfer observables in e(over→)p elastic scattering.

Author

Meziane M, Brash EJ, Gilman R, Jones MK, Luo W, Pentchev L, Perdrisat CF, Puckett AJ, Punjabi V, Wesselmann FR, Ahmidouch A, Albayrak I, Aniol KA, Arrington J, Asaturyan A, Ates O, Baghdasaryan H, Benmokhtar F, Bertozzi W, Bimbot L, Bosted P, Boeglin W, Butuceanu C, Carter P, Chernenko S, Christy E, Commisso M, Cornejo JC, Covrig S, Danagoulian S, Daniel A, Davidenko A, Day D, Dhamija S, Dutta D, Ent R, Frullani S, Fenker H, Frlez E, Garibaldi F, Gaskell D, Gilad S, Goncharenko Y, Hafidi K, Hamilton D, Higinbotham DW, Hinton W, Horn T, Hu B, Huang J, Huber GM, Jensen E, Kang H, Keppel C, Khandaker M, King P, Kirillov D, Kohl M, Kravtsov V, Kumbartzki G, Li Y, Mamyan V, Margaziotis DJ, Markowitz P, Marsh A, Matulenko Y, Maxwell J, Mbianda G, Meekins D, Melnik Y, Miller J, Mkrtchyan A, Mkrtchyan H, Moffit B, Moreno O, Mulholland J, Narayan A, Nuruzzaman, Nedev S, Piasetzky E, Pierce W, Piskunov NM, Prok Y, Ransome RD, Razin DS, Reimer PE, Reinhold J, Rondon O, Shabestari M, Shahinyan A, Shestermanov K, Širca S, Sitnik I, Smykov L, Smith G, Solovyev L, Solvignon P, Subedi R, Suleiman R, Tomasi-Gustafsson E, Vasiliev A, Vanderhaeghen M, Veilleux M, Wojtsekhowski BB, Wood S, Ye Z, Zanevsky Y, Zhang X, Zhang Y, Zheng X, and Zhu L

Abstract

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 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(e[over →],e(')p[over →]) reaction for three different beam energies at a Q(2)=2.5  GeV(2), spanning a wide range of the kinematic parameter ε. The ratio R, which equals μ(p)G(E)/G(M) in the Born approximation, is found to be independent of ε at the 1.5% level. The ε dependence of the longitudinal polarization transfer component P(ℓ) shows an enhancement of (2.3±0.6)% relative to the Born approximation at large ε., (© 2011 American Physical Society)

Published
2011
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47. 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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48. Measurements of the electric form factor of the neutron up to Q2=3.4 GeV2 using the reaction 3He(e,e'n)pp.

Author

Riordan S, Abrahamyan S, Craver B, Kelleher A, Kolarkar A, Miller J, Cates GD, Liyanage N, Wojtsekhowski B, Acha A, Allada K, Anderson B, Aniol KA, Annand JR, Arrington J, Averett T, Beck A, Bellis M, Boeglin W, Breuer H, Calarco JR, Camsonne A, Chen JP, Chudakov E, Coman L, Crowe B, Cusanno F, Day D, Degtyarenko P, Dolph PA, Dutta C, Ferdi C, Fernández-Ramírez C, Feuerbach R, Fraile LM, Franklin G, Frullani S, Fuchs S, Garibaldi F, Gevorgyan N, Gilman R, Glamazdin A, Gomez J, Grimm K, Hansen JO, Herraiz JL, Higinbotham DW, Holmes R, Holmstrom T, Howell D, de Jager CW, Jiang X, Jones MK, Katich J, Kaufman LJ, Khandaker M, Kelly JJ, Kiselev D, Korsch W, LeRose J, Lindgren R, Markowitz P, Margaziotis DJ, Beck SM, Mayilyan S, McCormick K, Meziani ZE, Michaels R, Moffit B, Nanda S, Nelyubin V, Ngo T, Nikolenko DM, Norum B, Pentchev L, Perdrisat CF, Piasetzky E, Pomatsalyuk R, Protopopescu D, Puckett AJ, Punjabi VA, Qian X, Qiang Y, Quinn B, Rachek I, Ransome RD, Reimer PE, Reitz B, Roche J, Ron G, Rondon O, Rosner G, Saha A, Sargsian MM, Sawatzky B, Segal J, Shabestari M, Shahinyan A, Shestakov Y, Singh J, Sirca S, Souder P, Stepanyan S, Stibunov V, Sulkosky V, Tajima S, Tobias WA, Udias JM, Urciuoli GM, Vlahovic B, Voskanyan H, Wang K, Wesselmann FR, Vignote JR, Wood SA, Wright J, Yao H, and Zhu X

Abstract

The electric form factor of the neutron was determined from studies of the reaction 3He(e,e'n)pp in quasielastic 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. More than doubling the Q2 range over which it is known, we find G(E)(n)=0.0236±0.0017(stat)±0.0026(syst), 0.0208±0.0024±0.0019, and 0.0147±0.0020±0.0014 for Q(2)=1.72, 2.48, and 3.41 GeV2, respectively.

Published
2010
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49. 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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50. Recoil polarization measurements of the proton electromagnetic form factor ratio to Q2 = 8.5  GeV2.

Author

Puckett AJ, Brash EJ, Jones MK, Luo W, Meziane M, Pentchev L, Perdrisat CF, Punjabi V, Wesselmann FR, Ahmidouch A, Albayrak I, Aniol KA, Arrington J, Asaturyan A, Baghdasaryan H, Benmokhtar F, Bertozzi W, Bimbot L, Bosted P, Boeglin W, Butuceanu C, Carter P, Chernenko S, Christy E, Commisso M, Cornejo JC, Covrig S, Danagoulian S, Daniel A, Davidenko A, Day D, Dhamija S, Dutta D, Ent R, Frullani S, Fenker H, Frlez E, Garibaldi F, Gaskell D, Gilad S, Gilman R, Goncharenko Y, Hafidi K, Hamilton D, Higinbotham DW, Hinton W, Horn T, Hu B, Huang J, Huber GM, Jensen E, Keppel C, Khandaker M, King P, Kirillov D, Kohl M, Kravtsov V, Kumbartzki G, Li Y, Mamyan V, Margaziotis DJ, Marsh A, Matulenko Y, Maxwell J, Mbianda G, Meekins D, Melnik Y, Miller J, Mkrtchyan A, Mkrtchyan H, Moffit B, Moreno O, Mulholland J, Narayan A, Nedev S, Nuruzzaman, Piasetzky E, Pierce W, Piskunov NM, Prok Y, Ransome RD, Razin DS, Reimer P, Reinhold J, Rondon O, Shabestari M, Shahinyan A, Shestermanov K, Sirca S, Sitnik I, Smykov L, Smith G, Solovyev L, Solvignon P, Subedi R, Tomasi-Gustafsson E, Vasiliev A, Veilleux M, Wojtsekhowski BB, Wood S, Ye Z, Zanevsky Y, Zhang X, Zhang Y, Zheng X, and Zhu L

Abstract

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, 6.7, and 8.5  GeV2. By extending the range of Q2 for which G(E)(p) is accurately determined by more than 50%, these measurements will provide significant constraints on models of nucleon structure in the nonperturbative regime.

Published
2010
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