Flavor asymmetry of polarized antiquark distributions and semi-inclusive DIS

The 1/Nc–expansion of QCD suggests large flavor asymmetries of the polarized antiquark distributions in the nucleon. This is confirmed by model calculations in the large–Nc limit (chiral quark–soliton model), which give sizable results for ∆ū(x)−∆d̄(x) and ∆ū(x)+∆d̄(x)−2∆s̄(x). We compute the contributions of these flavor asymmetries to the spin asymmetries in hadron production in semi-inclusive deep–inelastic scattering. We show that the large flavor asymmetries predicted by the chiral quark–soliton model are consistent with the recent HERMES data for spin asymmetries in charged hadron production. 1 E-mail: [email protected] 2 E-mail: [email protected] 3 E-mail: [email protected] 4 E-mail: [email protected]