Off-forward quark distributions of the nucleon in the large N_c limit

Abstract

We study the off-forward quark distributions (OFQD's) in the chiral quark-soliton model of the nucleon. This model is based on the large-N_c picture of the nucleon as a soliton of the effective chiral lagrangian and allows to calculate the leading twist quark- and antiquark distributions at a low normalization point. We demonstrate the consistency of the approach by checking various sum rules for the OFQD's. We present numerical estimates of the isosinglet distribution H(x,ξ,Δ^2). In contrast to other approaches we find a strong qualitative dependence on the longitudinal momentum transfer, ξ. In particular, H(x,ξ,Δ^2) as a function of x exhibits fast crossovers at |x| = ξ/2. Such behaviour could lead to a considerable enhancement of the deeply-virtual Compton scattering cross section.