Critical Couplings in Crystalline Color Superconductivity

Abstract

By solving the Schwinger-Dyson equations, we analyze the pairing of quarks in asymmetric quark matter where up and down quarks have different chemical potentials. We show that in asymmetric quark matter, a crystalline color-superconducting gap opens when the quark coupling is stronger than a critical value. The critical coupling is nonzero, because the infrared divergence is lessened when the momenta of pairing quarks are not opposite. The superconducting gaps and the critical couplings are calculated both at high and intermediate densities.