The instanton based Chiral Quark Soliton Model: Form factors and (skewed) parton distributions

Abstract

The Chiral Quark Soliton Model is presented and its applications to electromagnetic and axial form factors and to forward and non-forward parton distributions of the nucleon are reviewed. The model is an effective chiral field theory for interacting constituent quark fields. It has been derived by Diakonov and Petrov from the QCD assuming that the gluonic field of the QCD vacuum is dominated by instantons. The model fulfils automatically all requirements for the description of partonic distributions as e.g. sum rules, positivity of quark- and antiquark distributions etc. In this paper numerical results are shown for recently measured antiquark distributions d(x) - u(x) , Δ d(x) - Δ u(x) and for the transvensity distribution δ d(x) - δ u(x) . Explicit calculations for the heavily discussed skewed (off-forward) parton distributions are presented.