Eur. Phys. J. A 14, 95-103 (2002)
DOI: 10.1140/epja/iepja1332
Single-spin asymmetry parameter from deeply virtual Compton scattering of hadrons up to twist-3 accuracy
I. Pion case
I.V. Anikin1, 2, D. Binosi1, 3, R. Medrano1, S. Noguera1 and V. Vento1, 3, 41 Departamento de Física Teórica, Universidad de Valencia, E-46100 Burjassot, Spain
2 Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna, Russia
3 IFIC-CSIC, E-46071 Valencia, Spain
4 School of Physics, Korea Institute for Advanced Study, Seoul 130-012, Korea
Vicente.Vento@uv.es
(Received: 7 November 2001 / Revised version: 6 February 2002 Communicated by A. Schäfer)
Abstract
The study of deeply virtual Compton scattering (DVCS) has shown that
electromagnetic gauge invariance requires, to leading order, not only
twist-two but additional twist-three contributions. We apply this analysis
and, using the Ellis-Furmanski-Petronzio factorization scheme, compute the
single- (electron) spin asymmetry arising in the collision of longitudinally
polarized electrons with hadrons up to twist-3 accuracy. In order to
simplify the kinematics we restrict the actual calculation to pions in the
chiral limit. The process is described in terms of the generalized parton
distribution functions which we obtain within a bag model framework.
13.60.Fz - Elastic and Compton scattering.
12.38.Bx - Perturbative calculations.
© Società Italiana di Fisica, Springer-Verlag 2002