Nucleon parton distributions in the chiral theory of nucleon

Abstract At large Nc the nucleon can be viewed as a soliton of the effective chiral lagrangian. This picture of nucleons allows a consistent nonperturbative calculation of the leading-twist parton distributions at a low normalization point. We derive general formulae for the polarized and unpolarized distributions in the chiral quark-soliton model. The consistency of the approach is demonstrated by checking the baryon number, isospin and total momentum sum rules, as well as the Bjorken sum rule. We present results for the quark and antiquark distributions and find reasonable agreement with parametriza-tions of the data at a low normalization point. In particular, we obtain a sizeable fraction of antiquaries, in agreement with the phenomenological analysis.