1997/11/30 by Mark Alford, M. Alford, Krishna Rajagopal +3 · 48 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Pulsars and Gravitational Waves Research #Quantum Chromodynamics and Particle Interactions #hep-ph #hep-th #nucl-th
paper · pdf · doi:10.1016/s0370-2693(98)00051-3
published as Phys.Lett. B422 (1998) 247-256 · 13 pages, LaTeX, uses revtex. Typographical corrections, references revised
openalex publication_date 1998/03/01 · arxiv created 1998/04/14 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
We use a variational procedure to study finite density QCD in an approximation in which the interaction between quarks is modelled by that induced by instantons. We find that uniform states with conventional chiral symmetry breaking have negative pressure with respect to empty space at all but the lowest densities, and are therefore unstable. This is a precisely defined phenomenon which motivates the basic picture of hadrons assumed in the MIT bag model, with nucleons as droplets of chiral symmetry restored phase. At all densities high enough that the chirally symmetric phase fills space, we find that color symmetry is broken by the formation of a <qq> condensate of quark Cooper pairs. A plausible ordering scheme leads to a substantial gap in a Lorentz scalar channel involving quarks of two colors, and a much smaller gap in an axial vector channel involving quarks of the third color.