Scale-invariance and scale-breaking in parity-invariant three-dimensional QCD

Abstract

We present a numerical study of three-dimensional two-color QCD with N=0, 2, 4, 8 and 12 flavors of massless two-component fermions using parity-preserving improved Wilson-Dirac fermions. A finite volume analysis provides strong evidence for the presence of Sp(N) symmetry-breaking bilinear condensate when N≤2 and its absence for N≥8. A weaker evidence for the bilinear condensate is shown for N=4. We estimate the critical number of flavors below which scale-invariance is broken by the bilinear condensate to be between N=4 and 6.