Chiral corrections to the Roper mass

TL;DR

This paper studies how the Roper resonance mass varies with quark mass using relativistic chiral perturbation theory, providing a framework for lattice data extrapolation.

Contribution

It introduces a one-loop relativistic chiral perturbation theory approach with infrared regularization for analyzing the Roper mass dependence on quark mass.

Findings

Roper mass quark dependence similar to nucleon

Chiral expansion useful for lattice data extrapolation

Infrared regularization preserves chiral symmetry

Abstract

We analyze the quark mass dependence of the Roper mass to one-loop order in relativistic baryon chiral perturbation theory. The loop integrals are evaluated using infrared regularization which preserves chiral symmetry and establishes a chiral counting scheme. The derived chiral expansion of the Roper mass may prove useful for chiral extrapolations of lattice data. For couplings of natural size the quark mass dependence of the Roper mass is similar to the one of the nucleon.