Three-dimensional lattice multiflavor scalar chromodynamics: interplay between global and gauge symmetries
Abstract
We study the nature of the finite-temperature transition of the three-dimensional scalar chromodynamics with Nf flavors. These models are constructed by considering maximally O(M)-symmetric multicomponent scalar models, whose symmetry is partially gauged to obtain SU(Nc) gauge theories, with a residual nonabelian global symmetry given by U(Nf) for Nc>2 and Sp(Nf) for Nc=2, so that M = 2 Nc Nf. We find that their finite-temperature transition is continuous for Nf=2 and for all values of Nc we investigated, Nc=2,3,4. Such continuous transitions belong to universality classes related to the global symmetry group of the theory. For Nc=2 it belongs to the SO(5)=Sp(2)/Z2 universality class, while for Nc>2 it belongs to the SO(3)=SU(2)/Z2 universality class. For Nf>2, the transition is always of first order. These results match the predictions obtained by using the effective Landau-Ginzburg-Wilson approach in terms of a gauge-invariant order parameter. Our results indicate that the nonabelian gauge degrees of freedom are irrelevant at the transition. These conclusions are supported by an analysis of gauge-field dependent correlation functions, that are always short-ranged, even at the transition.