Gluonic phase versus LOFF phase in two-flavor quark matter

Abstract: We study the gluonic phase in a two-flavor color superconductor as a function of the ratio of the gap over the chemical potential mismatch,$\Delta/\delta\mu$. We find that the gluonic phase resolves the chromomagnetic instability encountered in a two-flavor color superconductor for $\Delta/\delta \mu < \sqrt{2}$. We also calculate approximately the free energies of the gluonic phase and the single plane-wave LOFF phase and show that the former is favored over the latter for a wide range of coupling strengths.