Diquark Bose Condensates in High Density Matter and Instantons

Abstract

Instantons lead to strong correlations between up and down quarks with spin zero and anti-symmetric color wave functions. In cold and dense matter, $n_b>n_c\simeq 1f{m}^{-3}$ and $T<T_c\sim$ 50 MeV, these pairs Bose-condense, replacing the usual $<\bar{q}q>$ condensate and restoring chiral symmetry. At high density, the ground state is a color superconductor in which diquarks play the role of Cooper pairs. An interesting toy model is provided by QCD with two colors: it has a particle-anti-particle symmetry which relates $<\bar{q}q>$ and $<qq>$ condensates.

Comments: 4 pages ReVTeX, 2 eps-figures included using epsf.sty