Eur. Phys. J. A (2004) 19: 189-196
https://doi.org/10.1140/epjad/s2004-03-032-x

Cold and hot nuclear matter

Quark matter in neutron stars

INFN, and Dipartimento di Fisica dell’ Universita’ di Catania, via S. Sofia 64, 95123 Catania, Italy

Received: 7 August 2003
Published online: 12 February 2004

Abstract

The density of nuclear matter in the interior of neutron stars can reach values, for the largest masses, which can be compatible with the onset of hadron deconfinement. For the study of this possibility the only viable method at present is the comparison between the available nucleon and quark Equations of State (EoS) at increasing baryon density. It is then possible to trace the transition to the deconfined phase or the appearence of a mixed phase. We present recent results on the structure of neutron stars based on this procedure. For the nucleon matter, the microscopic many-body theory of the Nuclear Equation of State is discussed in the framework of the Bethe-Brueckner-Goldstone method. The expansion is extended up to the three hole-line diagrams contribution. For the quark matter, different models are used to generate the quark EoS. Despite the maximum mass of neutron stars turns out to be only marginally sensitive to the considered quark EoS, it is found that the structure of neutron stars can drastically depend on the adopted model.