- Strange quark stars within the Nambu-Jona-Lasinio model (2001)
- We investigate the properties of charge neutral equilibrium cold quark matter within the Nambu Jona-Lasinio model. The calculations are carried out for di erent ratios of coupling constants characterizing the vector and scalar 4 fermion interaction, xi = GV /GS. It is shown that for xi < 0.4 matter is self bound and for xi < 0.65 it has a first order phase transition of the liquid gas type. The Gibbs conditions in the mixed phase are applied for the case of two chemical potentials associated with the baryon number and electric charge. The characteristics of the quark stars are calculated for xi = 0, 0.5 and 1. It is found that the phase transition leads to a strong density variation at the surface of these stars. For xi = 1 the properties of quark stars show behaviors typical for neutron stars. At >< 0.4 the stars near to the maximum mass have a large admixture of strange quarks in their interiors. PACS number: 14.65.-q, 26.60.+c, 97.10.-q
- Catastrophic rearrangement of a compact star due to the quark core formation (2002)
- We study properties of compact stars with the deconfinement phase transition in their interiors. The equation of state of cold baryon-rich matter is constructed by combining a relativistic mean-field model for the hadronic phase and the MIT Bag model for the deconfined phase. In a narrow parameter range two sequences of compact stars (twin stars), which differ by the size of the quark core, have been found. We demonstrate the possibility of a rapid transition between the twin stars with the energy release of about 10 ^52 ergs. This transition should be accompanied by the prompt neutrino burst and the delayed gamma-ray burst.