Study of the nucleon spin-dependent structure function $g_1$. A comparison with recent HERMES and COMPASS data

TL;DR

This paper predicts the nucleon spin structure function $g_1$ using a unified approach that combines LO DGLAP evolution with double logarithmic resummation, comparing results with recent experimental data from HERMES and COMPASS.

Contribution

It introduces a method that integrates LO DGLAP evolution with $ln^2(x)$ resummation and explores the effects of different input parametrizations and running coupling on $g_1$ predictions.

Findings

Singular input parametrization can mimic $ln^2(x)$ resummation effects.

The impact of a more running coupling on the results is analyzed.

Comparison with HERMES and COMPASS data shows good agreement.

Abstract

Predictions for the spin dependent structure function $g_1$ of the nucleon are presented. We use an unified approach incorporating the LO DGLAP evolution and the resummation of double logarithmic terms $ln^2(x)$. We show, that the singular input parametrisation as $x\to 0$ can be a substitute of the $ln^2(x)$ resummation. An impact of the `more running' coupling is discussed. We determine the contribution to the Bjorken sum rule solving the evolution equation for the truncated moment of $g_1^{NS}$. A comparison with the re-analysed HERMES and COMPASS data is given.