A simple model for PDFs and nPDFs

TL;DR

This paper derives an analytical solution to QCD evolution equations for PDFs and nPDFs, fitting experimental data to propose a model for nuclear modifications of parton densities, with implications for understanding nuclear effects in deep inelastic scattering.

Contribution

It provides an analytical solution to QCD evolution equations and introduces a model for nuclear medium modifications of parton densities based on a global data analysis.

Findings

Analytical solution of QCD evolution equations for PDFs and nPDFs.

Fitted model parameters to experimental deep inelastic scattering data.

Predicted nuclear parton distribution functions for various nuclear targets.

Abstract

We present the main results of our recent papers, where we derived an analytical solution of the QCD evolution equations for parton distribution functions. The valence and non-singlet quark components satisfy the Gross-Llewellyn-Smith and Gottfried sum rules, respectively, while momentum conservation is maintained for the singlet quark and gluon densities. Several phenomenological parameters were extracted from a combined fit to precision data on the proton structure function $F_2(x,Q^2)$ collected by the BCDMS, H1, and ZEUS Collaborations, comprising a total of 933 points from 5 datasets. We proposed a model for nuclear medium modifications of parton densities. The approach is based on a global analysis of available deep inelastic scattering data for different nuclear targets within the rescaling model, incorporating Fermi motion effects. By fitting the rescaling parameters to experimental data on the ratio $F_2^A(x,Q^2)/F_2^{D}(x,Q^2)$ for several nuclear targets $A$, we obtained predictions for nuclear parton distribution functions.