Third-order QCD corrections to the charged-current structure function F_3

TL;DR

This paper calculates third-order QCD corrections to the structure function F_3 in deep-inelastic scattering, improving precision in determining the strong coupling constant and power corrections from experimental data.

Contribution

It provides the first complete three-loop coefficient function for F_3, enhancing theoretical predictions for neutrino-nucleon DIS at high precision.

Findings

Third-order corrections dominate at moderate x values.

The expansion of F_3 in alpha_s is stable across relevant x ranges.

At small x, new color structures appear in the corrections.

Abstract

We compute the coefficient function for the charge-averaged W^(+/-)-exchange structure function F_3 in deep-inelastic scattering (DIS) to the third order in massless perturbative QCD. Our new three-loop contribution to this quantity forms, at not too small values of the Bjorken variable x, the dominant part of the next-to-next-to-next-to-leading order corrections. It thus facilitates improved determinations of the strong coupling alpha_s and of 1/Q^2 power corrections from scaling violations measured in neutrino-nucleon DIS. The expansion of F_3 in powers of alpha_s is stable at all values of x relevant to measurements at high scales Q^2. At small x the third-order coefficient function is dominated by diagrams with the colour structure d_abc d^abc not present at lower orders. At large x the coefficient function for F_3 is identical to that of F_1 up to terms vanishing for x to 1.