Shear viscosity from kaon condensation in color-flavor-locked quark matter

Understand

We calculate the kaonic contribution to the shear viscosity of quark matter in the kaon-condensed color-flavor locked phase (CFL-K0).

• This contribution comes from a light pseudo-Goldstone boson which arises from the spontaneous breaking of the flavor symmetry by the kaon condensate.
• The other contribution, from the exactly massless superfluid 'phonon", has been calculated previously.
• We specialize to a particular form of the interaction lagrangian, parameterized by a single coupling.