Sigma-term physics in the perturbative chiral quark model - art. no. 054026

We apply the perturbative chiral quark model at one loop to analyze meson-b aryon sigma terms. Analytic expressions for these quantities are obtained i n terms of fundamental parameters of low-energy pion-nucleon physics (weak. pion decay constant, axial nucleon coupling, strong pion-nucleon form fact or) and of only one model parameter (radius of the nucleonic three-quark co re). Our result for the piN sigma term sigma (piN) approximate to 45 MeV is in good agreement with the value deduced by Gasser, Leutwyler, and Sainio using dispersion-relation techniques and exploiting the chiral symmetry con straints.