Meson mass at large baryon chemical potential in dense QCD

We reexamine the quark mass induced term in chiral Lagrangian in color–flavor locking phase in dense QCD, and show that the meson mass term is determined by three independent invariants under chiral–axial symmetry, and a meson mass is given in terms of the quark mass, gap, and the chemical potential by mπ2∼mq2ΔΔ̄/μ2ln(μ2/Δ2). Thus mesons become massless as μ→∞.