Polarization Transfer Observables in Elastic Electron Proton Scattering at $Q^2 = $2.5, 5.2, 6.8, and 8.5 GeV$^2$
Creators: name: Puckett, A. J. R.
name: Brash, E. J.
name: Jones, M. K.
name: Luo, W.
name: Meziane, M.
name: Pentchev, L.
name: Perdrisat, C. F.
name: Punjabi, V.
name: Wesselmann, F. R.
name: Afanasev, A.
name: Ahmidouch, A.
name: Albayrak, I.
name: Aniol, K. A.
name: Arrington, J.
name: Asaturyan, A.
name: Baghdasaryan, H.
name: Benmokhtar, F.
name: Bertozzi, W.
name: Bimbot, L.
name: Bosted, P.
name: Boeglin, W.
name: Butuceanu, C.
name: Carter, P.
name: Chernenko, S.
name: Christy, E.
name: Commisso, M.
name: Cornejo, J. C.
name: Covrig, S.
name: Danagoulian, S.
name: Daniel, A.
name: Davidenko, A.
name: Day, D.
name: Dhamija, S.
name: Dutta, D.
name: Ent, R.
name: Frullani, S.
name: Fenker, H.
name: Frlez, E.
name: Garibaldi, F.
name: Gaskell, D.
name: Gilad, S.
name: Gilman, R.
name: Goncharenko, Y.
name: Hafidi, K.
name: Hamilton, D.
name: Higinbotham, D. W.
name: Hinton, W.
name: Horn, T.
name: Hu, B.
name: Huang, J.
name: Huber, G. M.
name: Jensen, E.
name: Keppel, C.
name: Khandaker, M.
name: King, P.
name: Kirillov, D.
name: Kohl, M.
name: Kravtsov, V.
name: Kumbartzki, G.
name: Li, Y.
name: Mamyan, V.
name: Margaziotis, D. J.
name: Marsh, A.
name: Matulenko, Y.
name: Maxwell, J.
name: Mbianda, G.
name: Meekins, D.
name: Melnik, Y.
name: Miller, J.
name: Mkrtchyan, A.
name: Mkrtchyan, H.
name: Moffit, B.
name: Moreno, O.
name: Mulholland, J.
name: Narayan, A.
name: Nedev, S.
name: Nuruzzaman
name: Piasetzky, E.
name: Pierce, W.
name: Piskunov, N. M.
name: Prok, Y.
name: Ransome, R. D.
name: Razin, D. S.
name: Reimer, P.
name: Reinhold, J.
name: Rondon, O.
name: Shabestari, M.
name: Shahinyan, A.
name: Shestermanov, K.
name: Sirca, S.
name: Sitnik, I.
name: Smykov, L.
name: Smith, G.
name: Solovyev, L.
name: Solvignon, P.
name: Subedi, R.
name: Tomasi-Gustafsson, E.
name: Vasiliev, A.
name: Veilleux, M.
name: Wojtsekhowski, B. B.
name: Wood, S.
name: Ye, Z.
name: Zanevsky, Y.
name: Zhang, X.
name: Zhang, Y.
name: Zheng, X.
name: Zhu, L.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: The GEp-III and GEp-2$γ$ experiments were carried out in Jefferson Lab's (JLab's) Hall C from 2007-2008, to extend the knowledge of $G_E^p/G_M^p$ to the highest practically achievable $Q^2$ and to search for effects beyond the Born approximation in polarization transfer observables of elastic $\vec{e}p$ scattering. This article reports an expanded description of the common experimental apparatus and data analysis procedure, and the results of a final reanalysis of the data from both experiments, including the previously unpublished results of the full-acceptance data of the GEp-2$γ$ experiment. 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. The final GEp-III data are largely unchanged relative to the originally published results. The statistical uncertainties of the final GEp-2$γ$ data are significantly reduced at $ε= 0.632$ and $0.783$ relative to the original publication. The decrease with $Q^2$ of $G_E^p/G_M^p$ continues to $Q^2 = 8.5$ GeV$^2$, but at a slowing rate relative to the approximately linear decrease observed in earlier Hall A measurements. At $Q^2 = 2.5$ GeV$^2$, the proton form factor ratio $G_E^p/G_M^p$ shows no statistically significant $ε$-dependence, as expected in the Born approximation. The ratio $P_\ell/P_\ell^{Born}$ of the longitudinal polarization transfer component to its Born value shows an enhancement of roughly 1.4\% at $ε= 0.783$ relative to $ε= 0.149$, with $\approx 1.9σ$ significance based on the total uncertainty, implying a similar effect in the transverse component $P_t$ that cancels in the ratio $R$.
description: 44 pages, 28 figures. Archival publication for the GEp-III and GEp-2gamma experiments that ran in Jefferson Lab's experimental Hall C from October, 2007 to June, 2008. v2: final manuscript as accepted by PRC. v3: Replaced figures 13 and 19 with corrected versions from published Erratum. Also made minor corrections to the text and to Table XI reflecting the corrections in the published Erratum