On the flavour structure of the constituent quark

Abstract

We discuss the dressing of constituent quarks with a pseudoscalar meson cloud within the effective chiral quark model. symmetry breaking effects are included explicitly. Our results are compared with those of the traditional meson cloud approach in which pions are coupled to the nucleon. The pionic dressing of the constituent quarks explains the experimentally observed violation of the Gottfried sum rule and leads to an enhanced non-perturbative sea of pairs in the constituent quark and consequently in the nucleon. We find 2.5 times more pions and 10 - 15 times more kaons in the nucleon than in the traditional picture. The asymmetry obtained here is concentrated at somewhat smaller x and the ratio is somewhat different than in the traditional meson cloud model of the nucleon.