Parton densities in the modified chiral quark model

Abstract

The feature of parton densities inside the nucleon at low Q2 plays an essential role in particle physics. To calculate these densities there are different types of models, among which the chiral quark model (χQM) is the famous one. In this model, baryons are made from the ground states of constituent quarks, which are initially bare and finally surrounded by pseudo-scalar mesonic clouds. Here, in addition to mesonic clouds, we also take into account the gluonic clouds. The required bare quarks are obtained using the solution of the Dirac equation under a squared radial potential. The wavefunctions which are primarily in momentum space can be converted to a distribution in the x-Bjorken space by two different methods. Using the modified χQM, we extract the parton distributions inside the proton at low Q2 values and compare them with some experimental and phenomenological groups. The distributions can be evolved to high-energy scales, using the DGLAP evolution equations. The results are in good agreement with available experimental data and some phenomenological groups.