Phase diagram of neutral quark matter in nonlocal chiral quark models

dc.creatorDumm, D. Gomez
dc.creatorBlaschke, D. B.
dc.creatorGrunfeld, A. G.
dc.creatorScoccola, N. N.
dc.date2005-12-16
dc.date2006-06-30
dc.date.accessioned2026-07-07T06:54:16Z
dc.date.available2026-07-07T06:54:16Z
dc.descriptionWe consider the phase diagram of two-flavor quark matter under neutron star constraints for two nonlocal, covariant quark models within the mean field approximation. In the first case (Model I) the nonlocality arises from the regularization procedure, motivated by the instanton liquid model, whereas in the second one (Model II) a separable approximation of the one-gluon exchange interaction is applied. We find that Model II predicts a larger quark mass gap and a chiral symmetry breaking (CSB) phase transition line which extends 15-20% further into the phase diagram spanned by temperature (T) and chemical potential (mu). The corresponding critical temperature at mu=0, T_c(0)~140 MeV, is in better accordance to recent lattice QCD results than the prediction of the standard local NJL model, which exceeds 200 MeV. For both Model I and Model II we have considered various coupling strengths in the scalar diquark channel, showing that different low-temperature quark matter phases can occur at intermediate densities: a normal quark matter (NQM) phase, a two-flavor superconducting (2SC) quark matter phase and a mixed 2SC-NQM phase. Although in most cases there is also a gapless 2SC phase, this occurs in general in a small region at nonzero temperatures, thus its effect should be negligible for compact star applications.
dc.description12 pages, 3 figures. Minor changes in the Introduction and the discussion of results, Fig. 2 modified, references added. Final version published in PRD
dc.identifierhttps://arxiv.org/abs/hep-ph/0512218
dc.identifierhttp://arxiv.org/abs/hep-ph/0512218
dc.identifierPhys.Rev. D73 (2006) 114019
dc.identifierdoi:10.1103/PhysRevD.73.114019
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/105876
dc.subjectHigh Energy Physics - Phenomenology
dc.titlePhase diagram of neutral quark matter in nonlocal chiral quark models
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