Attractive Casimir effect in an infrared modified gluon bag model

TL;DR

This paper investigates how infrared modifications to gluon propagators influence the Casimir energy in a spherical bag model, revealing conditions under which the vacuum energy becomes attractive, aligning with hadron spectroscopy needs.

Contribution

It introduces a simple infrared modified gluon bag model to analyze the effects of analytic structure and geometry on vacuum energy, demonstrating attraction with certain gluon propagators.

Findings

Vacuum energy becomes attractive with infrared vanishing gluon propagators.

The model clarifies the role of geometry and analytic structure in Casimir energy calculations.

Supports the bag model's requirement for attractive vacuum energy in hadron spectroscopy.

Abstract

In this work, we are motivated by previous attempts to derive the vacuum contribution to the bag energy in terms of familiar Casimir energy calculations for spherical geometries. A simple infrared modified model is introduced which allows studying the effects of the analytic structure as well as the geometry in a clear manner. In this context, we show that if a class of infrared vanishing effective gluon propagators is considered, then the renormalized vacuum energy for a spherical bag is attractive, as required by the bag model to adjust hadron spectroscopy.