Flavor asymmetry of sea quarks in the unquenched quark model

The flavor asymmetry of the nucleon sea is studied in the framework of the unquenched quark model in which the effects of quark-antiquark pairs (u (u) over bar, d (d) over bar, and s (s) over bar) are taken into account via a microscopic, QCD-inspired, quark-antiquark creation mechanism. The inclusion of the q (q) over bar pairs leads to an excess of (d) over bar over (u) over bar, in agreement with the experimental data for the proton. In addition, the results for the flavor asymmetry of all ground-state octet and decuplet baryons are presented. The isospin symmetry leads to simple relations among the flavor asymmetries of octet and decuplet baryons. The flavor asymmetry of the Sigma(+) hyperon is predicted to be very similar to that of the proton and much larger than that for the Xi(0) hyperon. A comparison with other approaches shows large differences in the predictions for the flavor asymmetries of the hyperons.