Diquark composites in the color superconducting phase of two flavor   dense QCD
  We study the Bethe-Salpeter equations for spin zero diquark composites in the color superconducting phase of N_f=2 cold dense QCD. The explicit form of the spectrum of the diquarks, containing an infinite tower of narrow (at high density) resonances, is derived. It is argued that there are five pseudo-Nambu-Goldstone bosons (pseudoscalars) that remain almost massless at large chemical potential. These five pseudoscalars, along with the massless quarks of the third color should play an important role in the infrared dynamics of N_f=2 dense QCD. 
V. A. Miransky, I. A. Shovkovy and L. C. R. Wijewardhana