2002/01/31 by Thomas Schäfer, Thomas Schaefer · 7 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-lat #hep-ph
paper · pdf · doi:10.1103/physrevd.65.094033
published as Phys.Rev. D65 (2002) 094033 · 27 pages, 8 figures, minor revisions
arxiv created 2002/02/09 · openalex publication_date 2002/05/14 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We study instanton effects in QCD at very high baryon density. In this regime instantons are suppressed by a large power of (\ensuremathΛQCD/\ensuremathμ), where \ensuremathΛQCD is the QCD scale parameter and \ensuremathμ is the baryon chemical potential. Instantons are nevertheless important because they contribute to several physical observables that vanish to all orders in perturbative QCD. We study, in particular, the chiral condensate and its contribution mGB2\ensuremath∼m〈\ensuremathψ\ensuremathψ〉 to the masses of Goldstone bosons in the CFL phase of QCD with Nf=3 flavors. We find that at densities \ensuremathρ\ensuremath∼(5\ensuremath-10)\ensuremathρ0, where \ensuremathρ0 is the density of nuclear matter, the result is dominated by large instantons and subject to considerable uncertainties. We suggest that these uncertainties can be addressed using lattice calculations of the instanton density and the pseudoscalar diquark mass in QCD with two colors. We study the topological susceptibility and Witten-Veneziano type mass relations in both Nc=2 and Nc=3 QCD.