Parton distributions functions of pion, kaon and eta pseudoscalar mesons in the NJL model

Abstract

Parton distributions of pseudoscalar π,K and η mesons obtained within the NJL model using the Pauli–Villars regularization method are analyzed in terms of LO and NLO evolution, and the valence sea quark and gluon parton distributions for the pion are obtained at Q2 = 4GeV 2 and compared to existing parametrizations at that scale. Surprisingly, the NLO order effects turn out to be small compared to the LO ones. The valence distributions are in good agreement with experimental analyses, but the gluon and sea distributions come out to be softer in the high-x region and harder in the low-x region than the experimental analyses suggest.