Parton and Valon Distributions in the Nuclei

Abstract

In the valon model a nucleon is assumed to be a bound state of three valence quark clusters (valons). On this base the nucleus structure function which are made from nucleons are analysed. Here in the frame work of perturbative quantum chromodynamics (pQCD) the structure of the valons are described at next to leading-order (NLO) approximation. Using the constituent-quark model, structure function of nucleon is largely investigated in the nuclear medium. For a series of nuclei with the nuclear mass A such that 2 ≤ A ≤ 40 within the kinetic region 0.0001 ≤ x ≤ 0.9 which covers a wide range of x Bjorken variable, the theoretical predications are in good agreement with the existing lepton-nucleus data. A better and fair description of experimental data can be done, considering the shadowing effect for small values of x i.e. x < 0.01. Using the valon model, we do an analysis at the NLO approximation while shadowing effect is employed. A comparison between our theoretical prediction for nuclear parton distribution functions (nPDFs) and the results from recent collaborations like AT12 and HKN07 sets have been done. The results of our calculations are in good agreement with the experimental data in deep inelastic scattering (DIS) processes which covers an extended region of x-variable, including the small and also large x amounts and also with some theoretical models.