$x-$dependence of the quark distribution functions in the $\chi$CQM$_{{\rm config}}$

TL;DR

This paper extends the chiral constituent quark model with configuration mixing to include x-dependence in quark distribution functions, successfully fitting various experimental data and analyzing valence and sea quark asymmetries.

Contribution

It introduces a phenomenological approach to incorporate x-dependence into the QM_onfig, improving the description of quark distributions and related structure functions.

Findings

Achieves satisfactory fit for quark distribution functions and asymmetries.

Including configuration mixing improves the agreement with experimental data.

Model predictions at high x (  1) are consistent with available extrapolated data.

Abstract

Chiral constituent quark model with configuration mixing (\chiCQM_{{\rm config}}) is known to provide a satisfactory explanation of the ``proton spin problem'' and related issues. In order to enlarge the scope of \chiCQM_{{\rm config}}, we have attempted to phenomenologically incorporate x-dependence in the quark distribution functions. In particular, apart from calculating valence and sea quark distributions q_{{\rm val}}(x) and \bar q(x), we have carried out a detailed analysis to estimate the sea quark asymmetries \bar d(x)-\bar u(x), \bar d(x)/\bar u(x) and \frac{\bar d(x)-\bar u(x)}{u(x)-d(x)} as well as spin independent structure functions F_2^p(x)-F_2^n(x) and $F_2^n(x)/F_2^p(x)$ as functions of $x$. We are able to achieve a satisfactory fit for all the above mentioned quantities simultaneously. The inclusion of effects due to configuration mixing have also been examined in the case F_2^p(x)-F_2^n(x) and F_2^n(x)/F_2^p(x) where the valence quark distributions dominate and it is found that it leads to considerable improvement in the results. Further, the valence quark structure has also be tested by extrapolating the predictions of our model in the limit x \to 1 where data is not available.