THE ROLE OF POLARIZED VALONS IN THE FLAVOR SYMMETRY BREAKING OF NUCLEON SEA

Abstract

Next-to-leading order approximation of the quark helicity distributions are used in the framework of polarized valon model. The flavor-asymmetry in the light-quark sea of the nucleon can be obtained from the contributions of unbroken sea quark distributions. We employ the polarized valon model and extract the flavor-broken light sea distributions which are modeled with the help of a Pauli-blocking ansatz. Using this ansatz, we can obtain broken polarized valon distributions. From there and by employing convolution integral, broken sea quark distributions are obtainable in this framework. Our results for δu, δd, [Formula: see text] and [Formula: see text] are in good agreement with recent experimental data for polarized parton distribution from HERMES experimental group and also with GRSV model. Some information on orbital angular momentum as a main ingredient of total nucleon spin are given. The Q2 evolution of this quantity, using the polarized valon model is investigated.