The infrared limit of QCD effective string

TL;DR

This paper explores the universal properties of the effective string in confining gauge theories at large quark separations, revealing new boundary-induced Coulomb-like interactions and relations among physical parameters.

Contribution

It introduces a model-independent description of the effective string using conformal field theories and identifies a universal Coulomb-like potential differing from previous models.

Findings

Universal Coulomb-like interquark potential derived

Relations among string tension, flux tube thickness, and deconfining temperature established

Lower bounds on glueball spectrum discussed

Abstract

Some model-independent properties of the effective string of gauge field systems in the confining phase , for very large quark separations, are described in terms of two-dimensional conformal field theories. The constraints induced by the gauge theory at the boundaries of the effective string induce a Coulomb- like term in the interquark potential which is universal, but different from the one proposed by L\"uscher. Some universal relations among the string tension, the thickness of the colour flux tube, the location of the deconfining temperature and a lower bound of the glueball spectrum are discussed. (Lectures given at the XXXII Cracow School of Theoretical Physics, Zakopane, Poland 2-12 June 1992)