Publications (259) View all
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Article: Measurement of the 12C(e,e'p)11B Two-Body Breakup Reaction at High Missing Momentum Values
P. Monaghan, R. Shneor, R. Subedi, B. D. Anderson, K. Aniol, J. Annand, J. Arrington, H. Benaoum, F. Benmokhtar, P. Bertin, [......], G. M. Urciuoli, E. Voutier, K. Wang, J. W. Watson, L. B. Weinstein, B. Wojtsekhowski, S. Wood, H. Yao, X. Zheng, L. Zhu[show abstract] [hide abstract]
ABSTRACT: The five-fold differential cross section for the 12C(e,e'p)11B reaction was determined over a missing momentum range of 200-400 MeV/c, in a kinematics regime with Bjorken x > 1 and Q2 = 2.0 (GeV/c)2. A comparison of the results and theoretical models and previous lower missing momentum data is shown. The theoretical calculations agree well with the data up to a missing momentum value of 325 MeV/c and then diverge for larger missing momenta. The extracted distorted momentum distribution is shown to be consistent with previous data and extends the range of available data up to 400 MeV/c.01/2013; -
Article: Virtual Compton scattering and the generalized polarizabilities of the proton at Q2=0.92 and 1.76 GeV2
H. Fonvieille, G. Laveissière, N. Degrande, S. Jaminion, C. Jutier, L. Todor, R. Di Salvo, L. Van Hoorebeke, L. C. Alexa, B. D. Anderson, [......], E. Voutier, J. W. Watson, L. B. Weinstein, K. Wijesooriya, R. Wilson, B. B. Wojtsekhowski, D. G. Zainea, W-M. Zhang, J. Zhao, Z.-L. Zhou[show abstract] [hide abstract]
ABSTRACT: Virtual Compton scattering (VCS) on the proton has been studied at the Jefferson Laboratory using the exclusive photon electroproduction reaction ep→epγ. This paper gives a detailed account of the analysis which has led to the determination of the structure functions PLL−PTT/ε and PLT and the electric and magnetic generalized polarizabilities (GPs) αE(Q2) and βM(Q2) at values of the four-momentum transfer squared Q2=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 Q2 range and point to their nontrivial behavior.Phys. Rev. C. 07/2012; 86(1). -
Article: Virtual Compton Scattering and the Generalized Polarizabilities of the Proton at Q^2=0.92 and 1.76 GeV^2
H. Fonvieille, G. Laveissiere, N. Degrande, S. Jaminion, C. Jutier, L. Todor, R. Di Salvo, L. Van Hoorebeke, L. C. Alexa, B. D. Anderson, [......], E. Voutier, J. W. Watson, L. B. Weinstein, K. Wijesooriya, R. Wilson, B. B. Wojtsekhowski, D. G. Zainea, W. -M. Zhang, J. Zhao, Z. -L. Zhou[show abstract] [hide abstract]
ABSTRACT: Virtual Compton Scattering (VCS) on the proton has been studied at Jefferson Lab using the exclusive photon electroproduction reaction (e p --> e p 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 GeV^2. 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 non-trivial behavior.05/2012; -
Article: Methods for Optical Calibration of the BigBite Hadron Spectrometer
M. Mihovilovic, K. Allada, B. D. Anderson, J. R. M. Annand, T. Averett, A. Camsonne, R. W. Chan, J. -P. Chen, K. Chirapatpimol, C. W. de Jager, [......], G. Rosner, B. Sawatzky, M. Shabestari, A. Shahinyan, R. Shneor, S. Sirca, R. Subedi, V. Sulkosky, J. W. Watson, Y. -W. Zhang[show abstract] [hide abstract]
ABSTRACT: The techniques for optical calibration of Jefferson Lab's large-acceptance magnetic hadron spectrometer, BigBite, have been examined. The most consistent and stable results were obtained by using a method based on singular value decomposition. In spite of the complexity of the optics, the particles' positions and momenta at the target have been precisely reconstructed from the coordinates measured in the detectors by means of a single back-tracing matrix. The technique is applicable to any similar magnetic spectrometer and any particle type. For 0.55 GeV/c protons, we have established the vertex resolution of 1.2 cm, angular resolutions of 7 mrad and 16 mrad (in-plane and out-of-plane, respectively), and a relative momentum resolution of 1.6%.01/2012; -
Article: Probing Cold Dense Nuclear Matter
R. Subedi, R. Shneor, P Monaghan, B D Anderson, K. Aniol, J Annand, J. Arrington, H Benaoum, F. Benmokhtar, W. Bertozzi, [......], P Solvignon, V Sulkosky, G Urciuoli, E. Voutier, J. W. Watson, L B Weinstein, B Wojtsekhowski, S. Wood, X. C. Zheng, L Zhu[show abstract] [hide abstract]
ABSTRACT: The protons and neutrons in a nucleus can form strongly correlated nucleon pairs. Scattering experiments, where a proton is knocked-out of the nucleus with high momentum transfer and high missing momentum, show that in 12C the neutron-proton pairs are nearly twenty times as prevalent as proton-proton pairs and, by inference, neutron-neutron pairs. This difference between the types of pairs is due to the nature of the strong force and has implications for understanding cold dense nuclear systems such as neutron stars. Comment: 12 pages, 5 figures08/2009;