Magnetic interactions, the renormalization group and color superconductivity in high density QCD

We investigate the effect of long range magnetic interactions on the renormalization group (RG) evolution of local Cooper pairing interactions near the Fermi surface in high density QCD. We use an explicit cut-off on momentum modes, with special emphasis on screening effects such as Landau damping, to derive the RG equations in a gauge invariant, weak coupling expansion. We obtain the Landau pole Delta similar to mu g(-5)exp(-3 pi(2)/root 2 g), although the structure of our equations differs from previous results. We also investigate the gap equation, including condensates of higher angular momentum. We show that rotational invariance is unbroken at asymptotically high density, and verify that Delta is the correct value of the gap when higher modes are included in the analysis. (C) 2000 Elsevier Science B.V. All rights reserved.