Chiral symmetry restoration at large chemical potential in strongly coupled SU(N) gauge theories

Abstract

We show that at sufficiently large chemical potential SU(N) lattice gauge theories in the strong coupling limit with staggered fermions are in a chirally symmetric phase. The proof employs a polymer cluster expansion which exploits the anisotropy between timelike and spacelike directions in the presence of a quark chemical potential $\mu$. The expansion is shown to converge in the infinite volume limit at any temperature for sufficiently large $\mu$. All expectations of chirally non-invariant local fermion operators vanish identically, or, equivalently, their correlations cluster exponentially, within the expansion. The expansion itself may serve as a computational tool at large $\mu$ and strong coupling.