| Abstract: | We calculate generalized parton distribution functions in a field theoretic formalism using a covariant Bethe-Salpeter approach for the determination of the bound-state wave function. We describe the procedure in an exact calculation in scalar Electrodynamics proving that the relevant corrections outside our scheme vanish. We extend the formalism to the Nambu-Jona-Lasinio model, a realistic theory of the pion. We go in both cases beyond all previous calculations and discover that all important features required by general physical considerations, like symmetry properties, sum rules and the polynomiality condition, are explicitly verified. We perform a numerical study of their behavior in the weak- and strong-coupling limits.Received: 12 May 2003, Revised: 25 November 2003, Published online: 8 June 2004PACS: 24.10.Jv Relativistic models - 11.10.St Bound and unstable states; Bethe-Salpeter equations - 13.40.Gp Electromagnetic form factors - 13.60.Fz Elastic and Compton scatteringL. Theußl: Present address: TRIUMF, Vancouver, B.C. V6T 2A3, Canada; |
