Gauge Freedom in Chiral Gauge Theory with Vacuum Overlap -- Two-dimensional case

Abstract

Dynamical nature of the gauge degree of freedom and its effect to fermion spectrum are studied at $β=\infty$ for two-dimensional nonabelian chiral gauge theory in the vacuum overlap formulation. It is argue that the disordered gauge degree of freedom does not necessarily cause the massless chiral state in the (waveguide) boundary correlation function. An asymptotically free self-coupling for the gauge degree of freedom is introduced by hand at first. This allows us to tame the gauge fluctuation by approaching the critical point of the gauge degree of freedom without spoiling its disordered nature. We examine the spectrum in the boundary correlation function and find the mass gap of the order of the lattice cutoff. There is no symmetry against it. Then we argue that the decoupling of the gauge freedom can occur as the self-coupling is removed, provided that the IR fixed point due to the Wess-Zumino term is absent by anomaly cancellation.