Color superconductivity from magnetic interaction induced by flow equations

Abstract

Using flow equations, we derive an effective quark-quark interaction and obtain the coupled set of gap equations for the condensates of the CFL phase of massless N_f=3 dense QCD. We find two different sources of the infrared cutoff in magnetic interaction. When the penetration depth of the magnetic field inside the superconductor is less than the coherence length of quark-quark bound state, our results for the gap agree with those of Son. In the other case, we obtain parametric enhancement of the gap on the coupling constant.