Nucleon Form Factors to Next-to-Leading Order with Light-Cone Sum Rules

TL;DR

This paper calculates the next-to-leading order correction to nucleon electromagnetic form factors using light-cone sum rules, improving agreement with experimental data and addressing theoretical challenges.

Contribution

It provides the first NLO correction to light-cone sum rules for nucleon form factors, focusing on the M_N=0 approximation and analyzing gauge invariance issues.

Findings

The NLO correction to F_2 is approximately 60%.

Numerical results show improved agreement with experimental data.

Discussion of challenges beyond the M_N=0 approximation.

Abstract

We have calculated the leading-twist next-to-leading order (NLO), i.e., O(alpha_s), correction to the light-cone sum-rules prediction for the electromagnetic form factors of the nucleon. We have used the Ioffe nucleon interpolation current and worked in M_N=0 approximation, with M_N being the mass of the nucleon. In this approximation, only the Pauli form factor F_2 receives a correction and the calculated correction is quite sizable (cca 60%). The numerical results for the proton form factors show the improved agreement with the experimental data. We also discuss the problems encountered when going away from M_N=0 approximation at NLO, as well as, gauge invariance of the perturbative results. This work presents the first step towards the NLO accuracy in the light-cone sum rules for baryon form factors.