Phase diagram of chiral quark matter: From weakly to strongly coupled Fulde-Ferrell phase

摘要: We calculate the phase diagram of two-flavor quark matter within Nambu-Jona-Lasinio (NJL) model in temperature-flavor asymmetry plane case where there are three competing phases: homogeneous Bardeen-Cooper-Schrieffer (BCS) phase, unpaired and a with broken spatial symmetry, which is here taken to be counterpart Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) condensed physics. The system belongs universality class paramagnetic-ferromagnetic-helical systems, therefore contains tricritical Lifshitz point its diagram, momentum scale characterizing breaking translational invariance has critical exponent 1/2 leading order. Upon varying coupling constant theory we find that weak coupling, FFLO favored at arbitrary flavor asymmetries for sufficiently low temperatures; intermediate occupancy domain shifted towards larger asymmetries. Strong features new regime an inhomogeneous FF state, identify current-carrying Bose-Einstein condensate tightly bound up down quarks. temperature dependence gap function studied. It shown anomalous homogeneous, flavor-asymmetric transformed into normal (self-similar themore » BCS phase) once allowed for. analyze occupation numbers Cooper-pair wave show when orthogonal particle minority component blocking region (breach) around Fermi sphere weak-coupling limit, engulfs more low-momentum modes as increased, eventually leads topological change strong either two occupied strips or empty sphere. For nonorthogonal momenta, reduced extinct, i.e., no changes observed.« less