Non-supersymmetric duality cascade of QCD(BF) via semiclassics on ℝ2 × T2 with the baryon-’t Hooft flux

A bstract We study the phase diagrams of the bifundamental QCD (QCD(BF)) of different ranks, which is the 4d SU( N 1 ) × SU( N 2 ) gauge theory coupled with a bifundamental Dirac fermion. After discussing the anomaly constraints on possible vacuum structures, we apply a novel semiclassical approach on ℝ 2 × T 2 with the baryon-’t Hooft flux to obtain the concrete dynamics. The 2d effective theory is derived by the dilute gas approximation of center vortices, and it serves as the basis for determining the phase diagram of the model under the assumption of adiabatic continuity. As an application, we justify the non-supersymmetric duality cascade between different QCD(BF), which has been conjectured in the large- N argument. Combined with the semiclassics and the large- N 1 , 2 limit, we construct the explicit duality map from the parent theory, SU( N 1 ) × SU( N 2 ) QCD(BF), to the daughter theory, SU( N 1 ) × SU( N 2 − N 1 ) QCD(BF), including the correspondence of the coupling constants. We numerically examine the validity of the duality also for finite N 1 , 2 within our semiclassics, finding a remarkable agreement of the phase diagrams between the parent and daughter sides.