THE ROLE OF SELF-COUPLINGS OF SCALAR MESONS IN NEUTRON STAR MATTER

Autor:	M. Dillig, S. S. Pocha, A. R. Taurines, M. B. Pinto, César A. Z. Vasconcellos
Rok vydání:	2002
Předmět:	Physics Nuclear and High Energy Physics Particle physics Meson Equation of state (cosmology) Nuclear Theory Scalar (mathematics) Hyperon Scalar field dark matter General Physics and Astronomy Astronomy and Astrophysics Hartree Nuclear matter Quantum electrodynamics Nuclear Experiment Scalar meson
Zdroj:	Modern Physics Letters A. 17:1335-1344
ISSN:	1793-6632 0217-7323
DOI:	10.1142/s0217732302007727
Popis:	The influence of nonlinear cubic and quartic self-couplings of the scalar meson field in nuclear matter is investigated. In summing the leading tadpole corrections for the Dirac-vacuum, we compare two approaches, the modified relativistic Hartree approximation, applied to the Walecka model, and the relativistic Hartree approximation, employed to the nonlinear model, respectively. These two approaches render similar expressions for the equation of state of nuclear matter up to the fifth order in the scalar meson field. We find that, by exploring the parameter dependence of the two models, they yield similar results for the bulk static properties of nuclear matter. However, increasing the baryon density the two models start to deviate significantly, such as in the predictions for the maximal mass of a neutron star or in the role of hyperon degrees of freedom in dense matter. The results indicate that with increasing density, scalar meson self-couplings beyond the fourth order seem to play a significant role.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c4a096a0d880076d826817dd795572b5 https://doi.org/10.1142/s0217732302007727 Zobrazit plný text záznamu