Masses of Light and Heavy Mesons and Baryons: A Unified Picture

TL;DR

This paper presents a unified theoretical framework using Schwinger-Dyson and Bethe-Salpeter equations to compute the masses of various light and heavy baryons and mesons, aligning well with experimental data.

Contribution

It develops a symmetry-preserving contact interaction model that unifies the description of mesons and baryons across different quark flavors, extending previous work on meson properties.

Findings

Results agree well with experimental data.

The model effectively describes both light and heavy hadrons.

Parameter sets show robustness across different quark mass scales.

Abstract

We compute masses of positive parity spin-$1/2$ and $3/2$ baryons composed of $u$, $d$, $s$, $c$ and $b$ quarks in a quark-diaquark picture. The mathematical foundation for this analysis is implemented through a symmetry-preserving Schwinger-Dyson equations treatment of a vector-vector contact interaction, which preserves key features of quantum chromodynamics, such as confinement, chiral symmetry breaking and low energy Goldberger-Treiman relations. This study requires a computation of diquark correlations containing these quarks which in turn are readily inferred from solving the Bethe-Salpeter equations of the corresponding mesons. Therefore, it serves as a unified formalism for a multitude of mesons and baryons. It builds on our previous works on the study of masses, decay constants and form factors of quarkonia and light mesons, employing the same model. We use two sets of parameters, one which remains exactly the same for both the light and heavy sector hadrons, and another where the coupling strength is allowed to evolve according to the available mass scales of quarks. Our results are in very good agreement with the existing experimental data as well as predictions of other theoretical approaches whenever comparison is possible.