Structure functions from renormalization group improved small $x$ evolution

TL;DR

This paper improves the understanding of small $x$ structure functions by incorporating resummation effects into the evolution equations, achieving a good fit to HERA data and providing a consistent unintegrated gluon density.

Contribution

It introduces a renormalization group improved small $x$ evolution framework that accurately fits $F_2$ data including charm contributions.

Findings

Excellent fit to HERA $F_2$ data

Unintegrated gluon density consistent with existing models

Slightly higher intercept value in gluon density

Abstract

We perform the fit to the structure function $F_2$ data from HERA including terms due to the resummation at small $x$. The equation for the unintegrated gluon density is solved, previously established within the renormalization group improved small $x$ framework. We find very good description of the structure function $F_2$ and its charm component $F_2^c$. The resulting unintegrated gluon density is found to be consistent with the calculations based on similar approaches available in the literature, with only slightly higher intercept value.