New phases in CFL quark matter

Abstract

We consider order $\alpha_s$ corrections to the squared masses of the pseudo-Goldstone excitations about the ground state of dense quark matter. We show that these contributions tend to destabilize the vacuum, leading to a surprisingly complex phase structure for quark matter as a function of quark mass, even for small $\alpha_s$. In particular we find two new phases of CFL quark matter possibly relevant for the real world, for which the QCD angle theta-bar equals pi/2.