Final analysis of proton form factor ratio data at Q2=4.0, 4.8, and 5.6 GeV2

A. J R Puckett, E. J. Brash, O. Gayou, M. K. Jones, L. Pentchev, C. F. Perdrisat, V. Punjabi, K. A. Aniol, T. Averett, F. Benmokhtar, W. Bertozzi, L. Bimbot, J. R. Calarco, C. Cavata, Z. Chai, C. C. Chang, T. Chang, J. P. Chen, E. Chudakov, R. De LeoSonja Dieterich, R. Endres, M. B. Epstein, S. Escoffier, K. G. Fissum, H. Fonvieille, S. Frullani, J. Gao, F. Garibaldi, S. Gilad, R. Gilman, A. Glamazdin, C. Glashausser, J. Gomez, J. O. Hansen, D. Higinbotham, G. M. Huber, M. Iodice, C. W. De Jager, X. Jiang, M. Khandaker, S. Kozlov, K. M. Kramer, G. Kumbartzki, J. J. Lerose, D. Lhuillier, R. A. Lindgren, N. Liyanage, G. J. Lolos, D. J. Margaziotis, F. Marie, P. Markowitz, K. McCormick, R. Michaels, B. D. Milbrath, S. K. Nanda, D. Neyret, N. M. Piskunov, R. D. Ransome, B. A. Raue, R. Roché, M. Rvachev, C. Salgado, S. Sirca, I. Sitnik, S. Strauch, L. Todor, E. Tomasi-Gustafsson, G. M. Urciuoli, H. Voskanyan, K. Wijesooriya, B. B. Wojtsekhowski, X. Zheng, L. Zhu

Research output: Contribution to journalArticle

104 Citations (Scopus)

Abstract

Precise measurements of the proton electromagnetic form factor ratio R=μ pGEp/GMp using the polarization transfer method at Jefferson Lab have revolutionized the understanding of nucleon structure by revealing the strong decrease of R with momentum transfer Q2 for Q2 1 GeV2, in strong disagreement with previous extractions of R from cross-section measurements. In particular, the polarization transfer results have exposed the limits of applicability of the one-photon-exchange approximation and highlighted the role of quark orbital angular momentum in the nucleon structure. The GEp-II experiment in Jefferson Lab's Hall A measured R at four Q2 values in the range 3.5GeV2≤Q2≤5.6GeV2. A possible discrepancy between the originally published GEp-II results and more recent measurements at higher Q2 motivated a new analysis of the GEp-II data. This article presents the final results of the GEp-II experiment, including details of the new analysis, an expanded description of the apparatus, and an overview of theoretical progress since the original publication. The key result of the final analysis is a systematic increase in the results for R, improving the consistency of the polarization transfer data in the high-Q2 region. This increase is the result of an improved selection of elastic events which largely removes the systematic effect of the inelastic contamination, underestimated by the original analysis.

Original languageEnglish (US)
Article number045203
JournalPhysical Review C - Nuclear Physics
Volume85
Issue number4
DOIs
StatePublished - Apr 11 2012
Externally publishedYes

Fingerprint

form factors
protons
polarization
momentum transfer
contamination
angular momentum
quarks
electromagnetism
orbitals
cross sections
photons
approximation

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

Cite this

Puckett, A. J. R., Brash, E. J., Gayou, O., Jones, M. K., Pentchev, L., Perdrisat, C. F., ... Zhu, L. (2012). Final analysis of proton form factor ratio data at Q2=4.0, 4.8, and 5.6 GeV2. Physical Review C - Nuclear Physics, 85(4), [045203]. https://doi.org/10.1103/PhysRevC.85.045203

Final analysis of proton form factor ratio data at Q2=4.0, 4.8, and 5.6 GeV2. / Puckett, A. J R; Brash, E. J.; Gayou, O.; Jones, M. K.; Pentchev, L.; Perdrisat, C. F.; Punjabi, V.; Aniol, K. A.; Averett, T.; Benmokhtar, F.; Bertozzi, W.; Bimbot, L.; Calarco, J. R.; Cavata, C.; Chai, Z.; Chang, C. C.; Chang, T.; Chen, J. P.; Chudakov, E.; De Leo, R.; Dieterich, Sonja; Endres, R.; Epstein, M. B.; Escoffier, S.; Fissum, K. G.; Fonvieille, H.; Frullani, S.; Gao, J.; Garibaldi, F.; Gilad, S.; Gilman, R.; Glamazdin, A.; Glashausser, C.; Gomez, J.; Hansen, J. O.; Higinbotham, D.; Huber, G. M.; Iodice, M.; De Jager, C. W.; Jiang, X.; Khandaker, M.; Kozlov, S.; Kramer, K. M.; Kumbartzki, G.; Lerose, J. J.; Lhuillier, D.; Lindgren, R. A.; Liyanage, N.; Lolos, G. J.; Margaziotis, D. J.; Marie, F.; Markowitz, P.; McCormick, K.; Michaels, R.; Milbrath, B. D.; Nanda, S. K.; Neyret, D.; Piskunov, N. M.; Ransome, R. D.; Raue, B. A.; Roché, R.; Rvachev, M.; Salgado, C.; Sirca, S.; Sitnik, I.; Strauch, S.; Todor, L.; Tomasi-Gustafsson, E.; Urciuoli, G. M.; Voskanyan, H.; Wijesooriya, K.; Wojtsekhowski, B. B.; Zheng, X.; Zhu, L.

In: Physical Review C - Nuclear Physics, Vol. 85, No. 4, 045203, 11.04.2012.

Research output: Contribution to journalArticle

Puckett, AJR, Brash, EJ, Gayou, O, Jones, MK, Pentchev, L, Perdrisat, CF, Punjabi, V, Aniol, KA, Averett, T, Benmokhtar, F, Bertozzi, W, Bimbot, L, Calarco, JR, Cavata, C, Chai, Z, Chang, CC, Chang, T, Chen, JP, Chudakov, E, De Leo, R, Dieterich, S, Endres, R, Epstein, MB, Escoffier, S, Fissum, KG, Fonvieille, H, Frullani, S, Gao, J, Garibaldi, F, Gilad, S, Gilman, R, Glamazdin, A, Glashausser, C, Gomez, J, Hansen, JO, Higinbotham, D, Huber, GM, Iodice, M, De Jager, CW, Jiang, X, Khandaker, M, Kozlov, S, Kramer, KM, Kumbartzki, G, Lerose, JJ, Lhuillier, D, Lindgren, RA, Liyanage, N, Lolos, GJ, Margaziotis, DJ, Marie, F, Markowitz, P, McCormick, K, Michaels, R, Milbrath, BD, Nanda, SK, Neyret, D, Piskunov, NM, Ransome, RD, Raue, BA, Roché, R, Rvachev, M, Salgado, C, Sirca, S, Sitnik, I, Strauch, S, Todor, L, Tomasi-Gustafsson, E, Urciuoli, GM, Voskanyan, H, Wijesooriya, K, Wojtsekhowski, BB, Zheng, X & Zhu, L 2012, 'Final analysis of proton form factor ratio data at Q2=4.0, 4.8, and 5.6 GeV2', Physical Review C - Nuclear Physics, vol. 85, no. 4, 045203. https://doi.org/10.1103/PhysRevC.85.045203
Puckett AJR, Brash EJ, Gayou O, Jones MK, Pentchev L, Perdrisat CF et al. Final analysis of proton form factor ratio data at Q2=4.0, 4.8, and 5.6 GeV2. Physical Review C - Nuclear Physics. 2012 Apr 11;85(4). 045203. https://doi.org/10.1103/PhysRevC.85.045203
Puckett, A. J R ; Brash, E. J. ; Gayou, O. ; Jones, M. K. ; Pentchev, L. ; Perdrisat, C. F. ; Punjabi, V. ; Aniol, K. A. ; Averett, T. ; Benmokhtar, F. ; Bertozzi, W. ; Bimbot, L. ; Calarco, J. R. ; Cavata, C. ; Chai, Z. ; Chang, C. C. ; Chang, T. ; Chen, J. P. ; Chudakov, E. ; De Leo, R. ; Dieterich, Sonja ; Endres, R. ; Epstein, M. B. ; Escoffier, S. ; Fissum, K. G. ; Fonvieille, H. ; Frullani, S. ; Gao, J. ; Garibaldi, F. ; Gilad, S. ; Gilman, R. ; Glamazdin, A. ; Glashausser, C. ; Gomez, J. ; Hansen, J. O. ; Higinbotham, D. ; Huber, G. M. ; Iodice, M. ; De Jager, C. W. ; Jiang, X. ; Khandaker, M. ; Kozlov, S. ; Kramer, K. M. ; Kumbartzki, G. ; Lerose, J. J. ; Lhuillier, D. ; Lindgren, R. A. ; Liyanage, N. ; Lolos, G. J. ; Margaziotis, D. J. ; Marie, F. ; Markowitz, P. ; McCormick, K. ; Michaels, R. ; Milbrath, B. D. ; Nanda, S. K. ; Neyret, D. ; Piskunov, N. M. ; Ransome, R. D. ; Raue, B. A. ; Roché, R. ; Rvachev, M. ; Salgado, C. ; Sirca, S. ; Sitnik, I. ; Strauch, S. ; Todor, L. ; Tomasi-Gustafsson, E. ; Urciuoli, G. M. ; Voskanyan, H. ; Wijesooriya, K. ; Wojtsekhowski, B. B. ; Zheng, X. ; Zhu, L. / Final analysis of proton form factor ratio data at Q2=4.0, 4.8, and 5.6 GeV2. In: Physical Review C - Nuclear Physics. 2012 ; Vol. 85, No. 4.
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title = "Final analysis of proton form factor ratio data at Q2=4.0, 4.8, and 5.6 GeV2",
abstract = "Precise measurements of the proton electromagnetic form factor ratio R=μ pGEp/GMp using the polarization transfer method at Jefferson Lab have revolutionized the understanding of nucleon structure by revealing the strong decrease of R with momentum transfer Q2 for Q2 1 GeV2, in strong disagreement with previous extractions of R from cross-section measurements. In particular, the polarization transfer results have exposed the limits of applicability of the one-photon-exchange approximation and highlighted the role of quark orbital angular momentum in the nucleon structure. The GEp-II experiment in Jefferson Lab's Hall A measured R at four Q2 values in the range 3.5GeV2≤Q2≤5.6GeV2. A possible discrepancy between the originally published GEp-II results and more recent measurements at higher Q2 motivated a new analysis of the GEp-II data. This article presents the final results of the GEp-II experiment, including details of the new analysis, an expanded description of the apparatus, and an overview of theoretical progress since the original publication. The key result of the final analysis is a systematic increase in the results for R, improving the consistency of the polarization transfer data in the high-Q2 region. This increase is the result of an improved selection of elastic events which largely removes the systematic effect of the inelastic contamination, underestimated by the original analysis.",
author = "Puckett, {A. J R} and Brash, {E. J.} and O. Gayou and Jones, {M. K.} and L. Pentchev and Perdrisat, {C. F.} and V. Punjabi and Aniol, {K. A.} and T. Averett and F. Benmokhtar and W. Bertozzi and L. Bimbot and Calarco, {J. R.} and C. Cavata and Z. Chai and Chang, {C. C.} and T. Chang and Chen, {J. P.} and E. Chudakov and {De Leo}, R. and Sonja Dieterich and R. Endres and Epstein, {M. B.} and S. Escoffier and Fissum, {K. G.} and H. Fonvieille and S. Frullani and J. Gao and F. Garibaldi and S. Gilad and R. Gilman and A. Glamazdin and C. Glashausser and J. Gomez and Hansen, {J. O.} and D. Higinbotham and Huber, {G. M.} and M. Iodice and {De Jager}, {C. W.} and X. Jiang and M. Khandaker and S. Kozlov and Kramer, {K. M.} and G. Kumbartzki and Lerose, {J. J.} and D. Lhuillier and Lindgren, {R. A.} and N. Liyanage and Lolos, {G. J.} and Margaziotis, {D. J.} and F. Marie and P. Markowitz and K. McCormick and R. Michaels and Milbrath, {B. D.} and Nanda, {S. K.} and D. Neyret and Piskunov, {N. M.} and Ransome, {R. D.} and Raue, {B. A.} and R. Roch{\'e} and M. Rvachev and C. Salgado and S. Sirca and I. Sitnik and S. Strauch and L. Todor and E. Tomasi-Gustafsson and Urciuoli, {G. M.} and H. Voskanyan and K. Wijesooriya and Wojtsekhowski, {B. B.} and X. Zheng and L. Zhu",
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TY - JOUR

T1 - Final analysis of proton form factor ratio data at Q2=4.0, 4.8, and 5.6 GeV2

AU - Puckett, A. J R

AU - Brash, E. J.

AU - Gayou, O.

AU - Jones, M. K.

AU - Pentchev, L.

AU - Perdrisat, C. F.

AU - Punjabi, V.

AU - Aniol, K. A.

AU - Averett, T.

AU - Benmokhtar, F.

AU - Bertozzi, W.

AU - Bimbot, L.

AU - Calarco, J. R.

AU - Cavata, C.

AU - Chai, Z.

AU - Chang, C. C.

AU - Chang, T.

AU - Chen, J. P.

AU - Chudakov, E.

AU - De Leo, R.

AU - Dieterich, Sonja

AU - Endres, R.

AU - Epstein, M. B.

AU - Escoffier, S.

AU - Fissum, K. G.

AU - Fonvieille, H.

AU - Frullani, S.

AU - Gao, J.

AU - Garibaldi, F.

AU - Gilad, S.

AU - Gilman, R.

AU - Glamazdin, A.

AU - Glashausser, C.

AU - Gomez, J.

AU - Hansen, J. O.

AU - Higinbotham, D.

AU - Huber, G. M.

AU - Iodice, M.

AU - De Jager, C. W.

AU - Jiang, X.

AU - Khandaker, M.

AU - Kozlov, S.

AU - Kramer, K. M.

AU - Kumbartzki, G.

AU - Lerose, J. J.

AU - Lhuillier, D.

AU - Lindgren, R. A.

AU - Liyanage, N.

AU - Lolos, G. J.

AU - Margaziotis, D. J.

AU - Marie, F.

AU - Markowitz, P.

AU - McCormick, K.

AU - Michaels, R.

AU - Milbrath, B. D.

AU - Nanda, S. K.

AU - Neyret, D.

AU - Piskunov, N. M.

AU - Ransome, R. D.

AU - Raue, B. A.

AU - Roché, R.

AU - Rvachev, M.

AU - Salgado, C.

AU - Sirca, S.

AU - Sitnik, I.

AU - Strauch, S.

AU - Todor, L.

AU - Tomasi-Gustafsson, E.

AU - Urciuoli, G. M.

AU - Voskanyan, H.

AU - Wijesooriya, K.

AU - Wojtsekhowski, B. B.

AU - Zheng, X.

AU - Zhu, L.

PY - 2012/4/11

Y1 - 2012/4/11

N2 - Precise measurements of the proton electromagnetic form factor ratio R=μ pGEp/GMp using the polarization transfer method at Jefferson Lab have revolutionized the understanding of nucleon structure by revealing the strong decrease of R with momentum transfer Q2 for Q2 1 GeV2, in strong disagreement with previous extractions of R from cross-section measurements. In particular, the polarization transfer results have exposed the limits of applicability of the one-photon-exchange approximation and highlighted the role of quark orbital angular momentum in the nucleon structure. The GEp-II experiment in Jefferson Lab's Hall A measured R at four Q2 values in the range 3.5GeV2≤Q2≤5.6GeV2. A possible discrepancy between the originally published GEp-II results and more recent measurements at higher Q2 motivated a new analysis of the GEp-II data. This article presents the final results of the GEp-II experiment, including details of the new analysis, an expanded description of the apparatus, and an overview of theoretical progress since the original publication. The key result of the final analysis is a systematic increase in the results for R, improving the consistency of the polarization transfer data in the high-Q2 region. This increase is the result of an improved selection of elastic events which largely removes the systematic effect of the inelastic contamination, underestimated by the original analysis.

AB - Precise measurements of the proton electromagnetic form factor ratio R=μ pGEp/GMp using the polarization transfer method at Jefferson Lab have revolutionized the understanding of nucleon structure by revealing the strong decrease of R with momentum transfer Q2 for Q2 1 GeV2, in strong disagreement with previous extractions of R from cross-section measurements. In particular, the polarization transfer results have exposed the limits of applicability of the one-photon-exchange approximation and highlighted the role of quark orbital angular momentum in the nucleon structure. The GEp-II experiment in Jefferson Lab's Hall A measured R at four Q2 values in the range 3.5GeV2≤Q2≤5.6GeV2. A possible discrepancy between the originally published GEp-II results and more recent measurements at higher Q2 motivated a new analysis of the GEp-II data. This article presents the final results of the GEp-II experiment, including details of the new analysis, an expanded description of the apparatus, and an overview of theoretical progress since the original publication. The key result of the final analysis is a systematic increase in the results for R, improving the consistency of the polarization transfer data in the high-Q2 region. This increase is the result of an improved selection of elastic events which largely removes the systematic effect of the inelastic contamination, underestimated by the original analysis.

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