Light flavor baryon spectrum with higher order hyperfine interactions

TL;DR

This paper investigates light baryon spectra using a quark model that includes second-order hyperfine interactions from two-gluon exchange, resulting in improved agreement with experimental data and corrections to mass formulas.

Contribution

It introduces the inclusion of two-gluon exchange hyperfine interactions in baryon spectrum calculations, enhancing accuracy over traditional one-gluon models.

Findings

Better agreement with experimental baryon spectra.

Significant correction to Gell-Mann--Okubo mass formula.

Discussion of two-gluon effects on baryon excitations.

Abstract

We study the spectrum of light flavor baryons in a quark-model framework by taking into account the order $\mathrm{O}(\alpha_s^2)$ hyperfine interactions due to two-gluon exchange between quarks. The calculated spectrum agree better with the experimental data than the results from hyperfine interactions with only one-gluon exchange. It is also shown that two-gluon exchange hyperfine interactions bring a significantly improved correction to the Gell-Mann--Okubo mass formula. Two-gluon exchange corrections on baryon excitations (including negative parity baryons) are also briefly discussed.