What different variants of chiral EFT predict for the proton Compton differential cross section - and why

TL;DR

This paper compares various chiral effective field theory models' predictions for proton Compton scattering, emphasizing pion loops and heavy-baryon expansion effects, and corrects previous errors in loop calculations.

Contribution

It provides a comparative analysis of chiral EFT variants for gamma-proton scattering and rectifies earlier inaccuracies in pion loop computations.

Findings

Different chiral EFT variants yield varying differential cross section predictions.

Heavy-baryon expansion influences the behavior of pion loops significantly.

Previous erroneous results for pion loops are corrected.

Abstract

We compare the predictions of different variants of chiral effective field theory for the gamma-p elastic scattering differential cross section. We pay particular attention to the role of pion loops, and the impact that a heavy-baryon expansion has on the behavior of those loops. We also correct erroneous results for these loops that were published in Phys. Rev. C 67, 055202 (2003) [ arXiv:nucl-th/0212024 ].