Zimanyi-Moszkowski Model Research Articles

The effect of the delta-rich hadronic stellar matter in the maximum neutron star mass using the nonlinear Walecka and Zimanyi-Moszkowski models

In this work, the delta-rich hadronic stellar matter condensate is studied in the context of a relativistic mean field calculation for hadrons and mesons using the nonlinear Walecka (NLW) and Zimanyi-Moszkowski (ZM) models. Considering different values of delta-mesons coupling constants we present the delta matter effect in the equation of state in each of these models. Solving numerically the Tolman-Oppenheimer-Volkoff (TOV) equation, we obtain the maximum neutron star mass. We note that the NLW model provides a stiffer equation of state when compared to the ZM model for the same values of delta-mesons coupling constants, and as a consequence gives more massive neutron stars.

Comparison of Properties of the Simplest Neutron Stars in Three RMF Models

We study some properties of the simplest neutron stars (NSs) in the Glendenning–Moszkowski (GM) model, the hybrid derivative coupling (HD) model and the Zimanyi–Moszkowski (ZM) model in the framework of relativistic mean field (RMF) theory with and without the interaction by exchanging the S-meson. We show that the maximal mass of the NSs becomes smaller, but the redshift becomes larger from the GM model to the HD model, then to the ZM model. The interaction with the S-meson exchange enlarges the maximal mass of neutron stars, increases the relative population of charged particles (proton, electron and muon) and descends the relative population of neutron.

Remarks concerning kaon condensation in neutron stars

We reanalyze the existence of antikaon condensation phase in neutron stars with large mass and high gravitational redshift with not only the Glendenning-Moszkowski (GM) model but also the Zimanyi-Moszkowski (ZM) model in the framework of relativistic mean field (RMF) approximation theory. We find that even in the large mass and high redshift neutron stars, there are still some stiff enough equations of state of neutron star matter so that the pure antikaon condensation phase and the mixed phase of normal baryons and antikaon condensation can exist. By comparing the result given in the GM model and that in the ZM model, we notice that the existence of antikaon condensation phase does not depend on the details of the models.

Liquid–Gas Phase Transition for Asymmetric Nuclear Matter inthe Zimanyi–Moszkowski Model

By using the improved Zimanyi–Moszkowski (ZM) model including thefreedom of nucleons, σ mesons, ω mesons and ρmesons, we investigate the liquid–gas phase transition for asymmetricnuclear matter. It is found that the phase transition for asymmetricnuclear matter in the improved ZM model with the isospin vector ρmeson degree of freedom is well defined. The binodal surface, which isessential in the study of the phase transition process, is addressed.

The Landau parameters of nuclear matter in Zimanyi–Moszkowski models

The Landau parameters of nuclear matter have been calculated in Zimanyi–Moszkowski models, ZM0 and ZM3. We have also studied the influence on the final result of different orders in coupling terms between nucleons and mesons in the ZM0 model. The consequences of the results on the collective modes obtained in the space-like region have also been discussed.

The effects of the tensor coupling term in the Zimanyi-Moszkowski model for unpolarized nuclear matter

The effects of the tensor coupling term on nuclear matter in the Zimanyi-Moszkowki (ZM) model are investigated. It is shown that the tensor coupling term in the ZM model leaves the thermodynamical properties of nuclear matter almost unchanged. The corrections of tensor coupling to the critical point of the liquid-gas phase transition are given.

Model Study of Hot and Dense Baryonic Matter

The properties of baryonic matter have been investigated at finite density and temperature using different models. The variation of baryon masses and fractional number densities with baryon density and temperature obtained from different models have been compared. The quark hadron phase transition have been studied using Chiral Colour Dieletric (CCD) model in the quark sector. No phase transition have been observed for the different variants of the Zimanyi-Moszkowski models below T=60 MeV.

Thermodynamical fluctuations of meson fields for the Zimanyi-Moszkowski model

By using the real-time Green's function method with a pair cutoff approximation up to the second order, the thermodynamical fluctuation effects of meson fields on the Zimanyi-Moszkowski model are investigated. We find that in the fluctuation effects on the effective mass of the nucleon, the pressures are considerable in the low-baryon-density region and/or the high-temperature regions. The results of the Zimanyi-Moszkowski model and the Welecka model beyond the mean-field approximation are compared.

Does kaon condensation occur in neutron stars in the relativistic mean-field theory?

We discuss whether kaon condensation occurs in neutron star matter by using the Zimanyi-Moszkowski model in the relativistic mean-field theory. As a comparison, we also discuss the results from the Boguta-Bodmer model. We show that even though hyperons which may increase the critical condensation density are not included, kaon condensation might not occur in stable neutron stars for the Zimanyi-Moszkowski model.

Properties of Neutron Stars in the Relativistic Mean-Field Theory

view Abstract Citations (10) References (58) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Properties of Neutron Stars in the Relativistic Mean-Field Theory Cheng, K. S. ; Dai, Z. G. ; Yao, C. C. Abstract We study the properties of dense matter in neutron stars and calculate the structure of the stars based on the Zimanyi & Moszkowski (ZM) model in the relativistic mean-field theory. We also compare these results with those based on the Boguta & Bodmer (BB) model with a recent satisfactory parameter set. The two models satisfy the requirements from the observations of the masses of binary radio pulsars, the rotation frequencies of millisecond pulsars, the redshifts of the e+ annihilation lines of some γ-ray bursts if they are neutron stars, and the crustal moment of inertia of neutron stars deduced from the glitch events. Other observations may provide a way to discriminate between the two models. We suggest that the most important observational discriminant between these two models is found by observing the surface radiation of neutron stars, since the BB model leads to a large photon fraction of neutron star matter and rapid cooling of neutron stars, but the ZM model does not. Publication: The Astrophysical Journal Pub Date: June 1996 DOI: 10.1086/177325 Bibcode: 1996ApJ...464..348C Keywords: DENSE MATTER; STARS: PULSARS: GENERAL; RELATIVITY; STARS: INTERIORS; STARS: NEUTRON full text sources ADS | data products SIMBAD (7)