A statistical approach for flavor decomposition of the polarized quark distribution

The spin asymmetries of semi-inclusive cross sections for the production of positively and negatively charged hadrons has been measured in deep-inelastic scattering of polarized positrons on polarized hydrogen and 3He targets. The polarized quark and antiquark distribution is extracted as a function of x for up and down flavors. The up quark polarization is positive and the down quark polarization is negative in the measured range. The flavor decomposition of polarized quark distributions are evaluated within the range 0.033 < x < 0.465 at an average Q2 = 5GeV2 by using Thermodynamical Bag Model (TBM) and results have been compared with experimental values obtained in the Deep Inelastic Scattering (DIS) by HERMES Collaboration