Bosonic stringlike behavior and the Ultraviolet filtering of QCD

TL;DR

This study investigates how ultraviolet fluctuations affect the flux tube profile in finite-temperature QCD, revealing a connection to bosonic string behavior and the impact of UV filtering on flux tube broadening.

Contribution

It demonstrates that UV filtering aligns flux tube characteristics with free bosonic string predictions, highlighting the role of vacuum gauge fields in QCD flux tube behavior.

Findings

Flux tube width converges to bosonic string predictions after UV filtering.

Flux tube broadening is independent of UV filtering at large distances.

Results show a linearly divergent flux tube broadening consistent with string models.

Abstract

The gluonic action density is calculated in static mesons at finite temperature just below the deconfinement point. Our focus is to elucidate the role of vacuum ultraviolet fluctuations which are filtered using an improved smearing algorithm. In the intermediate source separation distance, where the free string picture poorly describes the flux tube width profile, we find upon reducing the vacuum action towards the classical instanton vacuum, the characteristics of the flux tube converge and compare favorably with the predictions of the free bosonic string. This result establishes a connection between the free string action and vacuum gauge fields and reveals the important role of ultraviolet physics in understanding the lattice data at this temperature scale. As a by-product of these calculations, we find the broadening of the QCD flux tube to be independent of the ultraviolet filtering at large distances. Our results exhibit a linearly divergent pattern in agreement with the string picture predictions.