STANDING WAVE GROUND STATE IN HIGH DENSITY, ZERO TEMPERATURE QCD AT LARGE NC

Abstract

Chiral symmetry breaking in QCD at zero temperature and high fermionic density is studied in the limit NC → ∞. We evaluate the effective action in the ladder approximation and integrate out fermions by introducing the bilocal field Σ(x, y), which enters the action as the mass operator for fermions. It is argued that at large fermionic chemical potential the mass operator Σ(x, y) has a small but nonvanishing expectation value. The condensate of the field Σ(x, y) and the fermionic condensate [Formula: see text] are inhomogeneous and anisotropic, so that the ground state has the structure of the standing wave with respect to these order parameters. Unlike possible color superconductivity, this symmetry breaking occurs to the leading order in 1/NC.