Broadening of the confining flux tube joining higher-representation sources

Abstract

In the context of confining gauge theories we study the flux tube generated by a pair of static sources belonging to higher rank representations of the gauge group. Using a simple geometric approach based on minimal surfaces describing the world-sheet of the underlying k-string, we infer logarithmic broadening of the flux tube as a function of source separation. It turns out that the coefficient of the logarithm does not depend on the specific representation of the source nor on its N-ality and is universal. Numerical results on a Z_4 gauge theory in three dimensions with static sources carrying two units of elementary flux compare very favourably with these predictions.

Comments: Talk at Lattice 2006; to be published in Proceedings Of Science as POS(LAT2006)070. 7 pages; 3 figures; corrected some typos in the last page