Properties of a protoneutron star in effective field theory

Abstract

The complete form of the equation of state of strangeness rich proto-neutron and neutron star matter has been obtained. The currently obtained lower value of the U (Λ) Λ potential at the level of 5 MeV permits the existence of additional parameter set which reproduces the weaker ΛΛ interaction. The effects of the strength of hyperon-hyperon interactions on the equations of state constructed for the chosen parameter set have been analyzed. It has been shown that replacing the strong Y − Y interaction model by the weak one introduces large differences in the composition of a proto-neutron star matter both in the strange and non-strange sectors. Also concentrations of neutrinos have been significantly altered in proto-neutron star interiors. The performed calculations have indicated that the change of the hyperon-hyperon coupling constants affects the value of the proto-neutron star maximum mass.

Neutrinos in Proto-neutron Star Models

“…1 (a). When hyperons are included, calculations have been done for the model (TM1-weak) which includes only ω-ρ coupling (φ and σ * mesons introduced in a minimal fashion [8,9]) and the one (EXT) that embodies a broad spectrum of nonlinear vector meson interactions presented in equation (2). Analysis of the results obtained for the matter of proto-neutron stars with nonzero strangeness indicates a clear stiffening of the EoS in the case of nonlinear model.…”

The effect of isoscalar-isovector coupling in infinite nuclear matter

“…The density at the interior core of the neutron star is very high ∼ 7-8ρ 0 so other hadronic part [43,44,[61][62][63] also come to play role on the equation of state. In this section, we extended our calculations to the system with octet (n, p,…”

“…Here we have taken the fourth order of expanded field and in addition to this we have taken the special interaction between the ω and ρ with a new coupling constant Λ v to get good result in the study of E sym and other co-efficients. The modified Lagrangian is given as [43,44]:…”

The Influence of the Enhanced Vector Meson Sector on the Properties of the Matter of Neutron Stars

“…In the light of these observations, it is important to know the evolutionary path that leads to the formation of a neutron star with such large mass. The most general scenario predicts that the formation of a cold catalysed object is preceded by a very specific phase of a hot neutron star with trapped neutrinos, which defines a proto-neutron star [3] , [4] . Understanding the evolution of neutron stars requires a detailed analysis of the properties of a proto-neutron star matter, especially the heat transport [5] .…”