An effective theory for baryons in the CFL phase

We study the effective field theory for fermions in the color-flavor locked (CFL) phase of high density QCD. The effective theory contains a flavor nonet of baryons interacting with a nonet of pseudoscalar Goldstone bosons as well as a singlet scalar Goldstone boson. The theory is similar to chiral perturbation theory in the one-baryon sector. We explain how to incorporate quark mass terms and study the spectrum as a function of the strange quark mass. Without meson condensation gapless baryon modes appears if the strange quark mass exceeds a critical value ms2/(2pF)=Δ, where pF is the Fermi momentum and Δ is the gap in the chiral limit. We show that kaon condensation leads to a rearrangement of the baryon spectrum and shifts the critical strange quark mass for the appearance of a gapless mode to higher values.