Nlo QCD Procedure with Respect to First Moments of Polarized Quark Densities

A procedure is proposed allowing the direct extraction of the first moments of the polarized quark distributions in the next to leading (NLO) QCD order from SIDIS data. The procedure is tested by appropriate simulations. It is shown that the extracted moments are in good agreement with the input parametrizations. The procedure is applied to recent HERMES data on pion asymmetries.