Pion-nucleon elastic scattering amplitude within covariant baryon chiral perturbation theory up to $O(p^4)$ level

TL;DR

This paper reviews the calculation of pion-nucleon elastic scattering amplitudes using covariant baryon chiral perturbation theory up to order $O(p^4)$, including numerical fits to experimental data and comparison with prior work.

Contribution

It provides a detailed $O(p^4)$ covariant baryon chiral perturbation theory calculation with numerical fits to partial wave data up to 1.20 GeV.

Findings

Successful fits to partial wave amplitudes up to 1.13 GeV and 1.20 GeV

Comparison shows consistency with previous studies

Demonstrates the effectiveness of the covariant approach at this order

Abstract

The $O(p^4)$ calculation on pion-nucleon elastic scattering amplitude in EOMS scheme within covariant baryon chiral perturbation theory is reviewed. Numerical fits to partial wave amplitudes up to $\sqrt{s}=1.13$ GeV and 1.20 GeV are performed and the results are compared with previous studies.