Eur. Phys. J. A (2005) 25: 293-298
https://doi.org/10.1140/epja/i2005-10095-1

Original Article

Neutron stars with isovector scalar correlations

¹ Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, 730000, Lanzhou, PRC
² Institute of High Energy Physics, Chinese Academy of Sciences, 100039, Beijing, PRC
³ Department of Technical Physics, Peking University, 100871, Beijing, PRC
⁴ Laboratori Nazionali del Sud, University of Catania, Via S. Sofia 44, I-95123, Catania, Italy
⁵ Cyclotron Institute, Texas A&M University, College Station, TX, USA

^* e-mail: ditoro@lns.infn.it

Received: 13 January 2005
Accepted: 15 June 2005
Published online: 25 August 2005

Abstract

Neutron stars with the isovector scalar δ-field are studied in the framework of the relativistic mean-field (RMF) approach in a pure-nucleon-plus-lepton scheme. The δ-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 the 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.