TY - JOUR
T1 - Theory of deeply virtual Compton scattering on the nucleon
AU - Belitsky, A. V.
AU - Müller, D.
AU - Kirchner, A.
N1 - Funding Information:
We would like to thank S. Stepanyan for providing us experimental data on the DVCS measurement with CLAS and communications on the Jefferson Lab experiment E-91-023, and H. Avakian for help to access the HERMES data on the beam–spin asymmetry in DVCS. We are grateful to V. Burkert, M. McDermott, M. Diehl, A. Freund, W.D. Nowak, A.V. Radyushkin, A. Schäfer, and M. Vanderhaeghen for discussions. This work was supported by the US Department of Energy under contract DE-FG02-93ER40762 (A.B.) and Studienstiftung des deutschen Volkes (A.K.). A.B. would like to thank the theory group at the University of Wuppertal for its hospitality.
PY - 2002/5/13
Y1 - 2002/5/13
N2 - We compute the cross section for leptoproduction of the real photon off the nucleon, which is sensitive to the deeply virtual Compton scattering amplitude with power accuracy. Our considerations go beyond the leading twist and involve the complete analysis in the twist-three approximation. We discuss consequences of the target and lepton beam polarizations for accessing the generalized parton distributions from experimental measurements of the azimuthal angular dependence of the final state photon or nucleon. We introduce several sets of asymmetries, defined as Fourier moments with respect to the azimuthal angle, which allow for a clear separation of the twist-two and -three sectors. Relying on a simple ansatz for the generalized parton distributions, we give quantitative estimates for azimuthal and spin asymmetries, discuss the uncertainties of these predictions brought in by radiative corrections, and compare them with experimental data as well as other theoretical expectations. Furthermore, we derive a general parametrization of the DVCS amplitudes in the region of small Bjorken variable. Published by Elsevier Science B.V.
AB - We compute the cross section for leptoproduction of the real photon off the nucleon, which is sensitive to the deeply virtual Compton scattering amplitude with power accuracy. Our considerations go beyond the leading twist and involve the complete analysis in the twist-three approximation. We discuss consequences of the target and lepton beam polarizations for accessing the generalized parton distributions from experimental measurements of the azimuthal angular dependence of the final state photon or nucleon. We introduce several sets of asymmetries, defined as Fourier moments with respect to the azimuthal angle, which allow for a clear separation of the twist-two and -three sectors. Relying on a simple ansatz for the generalized parton distributions, we give quantitative estimates for azimuthal and spin asymmetries, discuss the uncertainties of these predictions brought in by radiative corrections, and compare them with experimental data as well as other theoretical expectations. Furthermore, we derive a general parametrization of the DVCS amplitudes in the region of small Bjorken variable. Published by Elsevier Science B.V.
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U2 - 10.1016/S0550-3213(02)00144-X
DO - 10.1016/S0550-3213(02)00144-X
M3 - Article
AN - SCOPUS:0037071108
SN - 0550-3213
VL - 629
SP - 323
EP - 392
JO - Nuclear Physics B
JF - Nuclear Physics B
IS - 1-3
ER -