13 research outputs found
Formation of an ordered phase in neutron star matter
In this work, we explore the possible formation of ordered phases in hadronic
matter, related to the presence of hyperons at high densities. We analyze a
microscopic mechanism which can lead to the crystallization of the hyperonic
sector by the confinement of the hyperons on the nodes of a lattice. For this
purpose, we introduce a simplified model of the hadronic plasma, in which the
nuclear interaction between protons, neutrons and hyperons is mediated by meson
fields. We find that, for some reasonable sets of values of the model
parameters, such ordered phases are energetically favoured as density increases
beyond a threshold value.Comment: 16 pages, 14 figures, submitted to NP
Asymmetric nuclear matter and neutron star properties
In this work we calculate the total mass, radius, moment of inertia, and
surface gravitational redshift for neutron stars using various equations of
state (EOS). Modern meson-exchange potential models are used to evaluate the
-matrix for asymmetric nuclear matter. We calculate both a non-relativistic
and a relativistic EOS. Of importance here is the fact that relativistic
Brueckner-Hartree-Fock calculations for symmetric nuclear matter fit the
empirical data, which are not reproduced by non-relativistic calculations.
Relativistic effects are known to be important at high densities, giving an
increased repulsion. This leads to a stiffer EOS compared to the EOS derived
with a non-relativistic approach. Both the non-relativistic and the
relativistic EOS yield moments of inertia and redshifts in agreement with the
accepted values. The relativistic EOS yields, however, too large mass and
radius. The implications are discussed.Comment: Revtex, 16 pages, 6 figures include