Using highly excited baryons to catch the quark mass

TL;DR

This paper proposes using the spectrum of highly excited baryons, especially parity doubling, to investigate the running quark mass in QCD's mid-infrared regime, supported by a chiral-invariant quark model calculation.

Contribution

It introduces a novel approach to probe quark mass running through high-partial wave baryon spectra and provides the first computational evidence using a chiral-invariant quark model.

Findings

High-partial wave Delta* resonances show approximate degeneracy.

Three-quark states form flavor quartets with decreasing splittings at high energies.

The model supports the link between parity doubling and quark mass behavior.

Abstract

Chiral symmetry in QCD can be simultaneously in Wigner and Goldstone modes, depending on the part of the spectrum examined. The transition regime between both, exploiting for example the onset of parity doubling in the high baryon spectrum, can be used to probe the running quark mass in the mid-IR power-law regime. In passing we also argue that three-quark states naturally group into same-flavor quartets, split into two parity doublets, all splittings decreasing high in the spectrum. We propose that a measurement of masses of high-partial wave Delta* resonances should be sufficient to unambiguously establish the approximate degeneracy and see the quark mass running. We test these concepts with the first computation of the spectrum of high-J excited baryons in a chiral-invariant quark model.