Electroweak physics for color superconductivity - art. no. 114026

We construct the effective theories describing the electroweak interactions for the low-energy excitations associated with the color superconductive p hases of QCD at high matter density. The main result for the 3 flavor case is that the quasiparticle Goldstone boson pi (0) decay into two physical ma ssless photons is identical to the zero density case once we use the new Go ldstone decay constant and the modified electric charge (e) over tilde = e cos theta, with tan theta = 2e / root 3g(s) and g(s) the strong coupling co nstant. For 2 flavors we find that the coupling of the quarks to the neutra l vector boson Z(0) is modified with respect to the zero density case. We f inally point out possible applications of our result to the physics of comp act objects.