Pion-nucleon scattering around the delta resonance

TL;DR

This paper extends heavy-baryon chiral perturbation theory to effectively describe pion-nucleon scattering across a broad energy range, including the delta resonance region.

Contribution

It introduces a generalized framework of heavy-baryon chiral perturbation theory for pion-nucleon scattering from threshold to the delta peak.

Findings

Successful description of P-wave phase shifts

Framework applicable across a wide energy domain

Enhanced understanding of delta resonance effects

Abstract

We develop a generalized version of heavy-baryon chiral perturbation theory to describe pion-nucleon scattering in a kinematic domain that extends continuously from threshold to the delta-isobar peak. The $P$-wave phase shifts are used to illustrate this framework.