The Unreasonable effectiveness of effective string theory: The case of the 3D SU(2) Higgs model

We study string breaking in the three-dimensional SU(2) Higgs model, using values of the gauge coupling for which the confinementlike and Higgs-like regions of the phase diagram are separated just by a smooth crossover. We show that even in the presence of string breaking, the confining part of the interquark potential is well described by the effective string theory and that also the fine details of the effective string, like the higher order terms of the Nambu-Goto action or the boundary correction, can be precisely extracted from the fits and agree with the effective string predictions. We comment on the implications of these results for QCD simulations with dynamical quarks.