QCD vacuum and baryon masses

TL;DR

This paper investigates how the QCD vacuum, modeled via the Copenhagen picture, influences baryon masses within a constituent quark framework, revealing dependencies on vacuum parameters and contributions from gluon backgrounds.

Contribution

It introduces a novel approach to connect the QCD vacuum structure with baryon mass calculations using the Copenhagen model and constituent quarks.

Findings

Baryon masses depend on the QCD vacuum parameter.

The model satisfies the Gell-Mann-Okubo mass relation.

Effective quark masses include gluon background contributions.

Abstract

To study a possible role of the quantum chromodynamics (QCD) vacuum in nuclear and hadron physics, we evaluate a physical quantity in a candidate of the QCD vacuum. In this study we adopt the Copenhagen (spaghetti) picture of the QCD vacuum and calculate the ground-state baryon masses in a constituent quark model. We find that the calculated baryon mass does depend on a parameter that characterizes the Copenhagen picture of the QCD vacuum and satisfies the Gell-Mann-Okubo mass relation for the baryon octet. We also observe that the effective constituent quark mass defined in this study contains a contribution attributed to the Copenhagen vacuum, that is the gluon background field. We then estimate the value of the background gluon field as a function of the up (down) constituent quark mass by using the baryon masses as inputs.