2023/12/06 by Athenodorou, Andreas, Dubovsky, Sergei, Luo, Conghuan +1
#FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Theory (hep-th) #Statistical Mechanics (cond-mat.stat-mech)
paper · doi:10.48550/arxiv.2312.03855
Effective string theory has shown its universal power in the prediction of the spectrum of low-lying excited states of confining strings. Here we study confining flux tubes in ℤN gauge theories. For the N=2 theory, which corresponds to the 3d Ising gauge model, we compute the spectrum of low-lying excitations of confining strings and show that it agrees with the universal Nambu--Goto predictions except for an additional massive scalar resonance. This resonance, however, turns out to be a bulk glueball mixing with the flux tube excitations rather than a genuine string worldsheet state. In general ℤN gauge theories (dual to clock spin models), we observe a continuous phase transition for N ≥ 4, while for N > 5 it is governed by the O(2) universality class. The critical behavior of the string tension and mass gap is verified to be described by a dangerously irrelevant operator. At large N the glueball spectrum is expected to approach the spectrum of U(1) gauge theory, which is confirmed by our lattice data.