The Inverse Amplitude Method and Heavy Baryon Chiral Perturbation Theory applied to pion-nucleon scattering

TL;DR

This paper applies the Inverse Amplitude Method to unitarize heavy baryon chiral perturbation theory amplitudes for pion-nucleon scattering, successfully reproducing experimental features including the Delta(1232) resonance.

Contribution

It introduces a unitarization approach to heavy baryon chiral perturbation theory for pion-nucleon scattering, capturing resonance phenomena.

Findings

Reproduces scattering up to inelastic thresholds

Identifies different chiral constants after unitarization

Successfully models the Delta(1232) resonance

Abstract

We report on our present work, where by means of the Inverse Amplitude Method we unitarize the elastic pion nucleon scattering amplitudes of Heavy Barion Chiral Perturbation Theory at O(q^3). We reproduce the scattering up to the inelastic thresholds including the Delta(1232) resonance. The fitted chiral constants are rather different from those obtained by fitting the extrapolated threshold parameters for the non-unitarized theory.