Equation of state for compact stars from the Polyakov-loop Nambu-Jona-Lasinio model

• Applicant: Privatdozent Dr. Michael Buballa
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2010 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 159787049

We plan to investigate the EoS and phase diagram of quark matter at high densities, arbitrary isospin asymmetries and not too high temperatures in the vicinity of the chiral phase transition by describing baryons as relativistic bound states within a Nambu-Jona-Lasinio (NJL) type model, coupled to the Polyakov-loop potential. The outcome will be a new description of the hadron-to-quark matter transition, where nucleonic bound states get dissolved into resonances in the continuum of scattering states within a Mott-transition. Strong diquark correlations, an important ingredient of describing on- and off-shell nucleonic states will form a condensate of Cooper pairs, with an energy gap in the quark spectrum, unless isospin asymmetry will prevent this. The naive expectation that chiral symmetry restoration entails quark deconfinement may not be fulfilled if the large-Nc QCD prediction of a quarkyonic phase at low temperatures holds for the physical case of Nc ═3 too. This description will be of relevance for studies of the chiral phase transition in compact stars and in the course of supernova collapse evolution [1]. The approach to be developed will make new contributions to several unresolved issues: (i) the QCD phase diagram with the possible quarkyonic phase, (ii) a nuclear matter equation of state with chiral symmetry restoration, quark confinement, color superconductivity and hadron dissociation (generalized Beth-Uhlenbeck EoS), (iii) a possible shock wave formation due to the chiral phase transition as contribution to the supernora explosion mechanism.

• DFG Programme: Research Grants
• International Connection: Poland
• Participating Persons: Professor Dr. David Blaschke; Professor Dr. Gerd Röpke