DIS coefficient functions at four loops in QCD and beyond

TL;DR

This paper presents four-loop calculations of the lowest even moments of flavor-nonsinglet structure functions in QCD, providing numerical results and comparisons with threshold expansions near the limit where the momentum fraction approaches one.

Contribution

It provides new four-loop order results for structure function moments in QCD, extending the precision of theoretical predictions beyond previous calculations.

Findings

Numerical results for lowest even-$N$ moments at four loops.

Comparison with threshold expansion for large $N$.

Insights into behavior of structure functions near $x o 1$.

Abstract

We report results for the lowest even-$N$ moments of the flavor-nonsinglet structure functions $F_2$ and $F_L$ in QCD at the fourth order in the perturbative expansion in the strong coupling constant $\alpha_s$. Our results are presented in numerical form and we compare them with the leading and subleading terms of the threshold expansion for large values of $N$, which corresponds to the limit $x \to 1$.