Neutron stars with the isovector scalar delta-field are studied in the framework of the relativistic mean-field (RMF) approach in a pure-nucleon-plus-lepton scheme. The delta-field leads to a larger repulsion in dense neutron-rich matter and to a definite splitting of proton and neutron effective masses. Both features are influencing tire stability conditions of the neutron stars. Two parametrizations for the effective nonlinear Lagrangian density are used to calculate the nuclear equation of state (EOS) and the neutron star properties, and compared to correlated Dirac-Brueckner results. We conclude that in order to reproduce reasonable nuclear structure and neutron star properties within a RMF approach, a density dependence of the coupling constants is required.
Neutron stars with isovector scalar correlations
GRECO, VINCENZO
2005-01-01
Abstract
Neutron stars with the isovector scalar delta-field are studied in the framework of the relativistic mean-field (RMF) approach in a pure-nucleon-plus-lepton scheme. The delta-field leads to a larger repulsion in dense neutron-rich matter and to a definite splitting of proton and neutron effective masses. Both features are influencing tire stability conditions of the neutron stars. Two parametrizations for the effective nonlinear Lagrangian density are used to calculate the nuclear equation of state (EOS) and the neutron star properties, and compared to correlated Dirac-Brueckner results. We conclude that in order to reproduce reasonable nuclear structure and neutron star properties within a RMF approach, a density dependence of the coupling constants is required.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
