Strongly coupled quark matter: Chiral symmetry breaking in a magnetic field, and EoS in the BCS-BEC crossover
We explore chiral symmetry breaking in a magnetic field within a Nambu-Jona-Lasinio model of interacting massless quarks including tensor channels. The new interaction channels are opened up through Fierz identities due to the breaking of the rotational symmetry by the magnetic field. We demonstrate that the magnetic catalysis of chiral symmetry breaking leads to the generation of two independent condensates, the conventional chiral condensate and a spin-one condensate. While the chiral condensate generates a dynamical fermion mass, the spin-one condensate gives rise to a dynamical anomalous magnetic moment for the fermions. We also investigate the possibility of a crossover from a BCS to a BEC (Bardeen-Cooper-Schrieffer to Bose-Einstein Condensation) phase for strongly-coupled quark matter, and its implications for the system equation of state. The study uses zero temperature effective quark models at densities beyond nuclear density. We use mean-field approximation and consider quark-quark, quark-antiquark, and diquark-diquark interactions. We determine the region of parameters where the crossover can take place for a stable system (i.e. that with a corresponding positive pressure). To carry out this investigation, we first use a simple relativistic model of one-flavor fermions, and then, we consider a more realistic two-flavor model for strongly interacting quarks
Portillo Vazquez, Israel, "Strongly coupled quark matter: Chiral symmetry breaking in a magnetic field, and EoS in the BCS-BEC crossover" (2014). ETD Collection for University of Texas, El Paso. AAI3636296.