The influence of the strength of hyperon–hyperon interactions on neutron star properties

Abstract

Abstract. An equation of state of neutron star matter with strange baryons has been obtained. The effects of the strength of hyperon-hyperon interactions on the equations of state constructed for the chosen parameter sets have been analyzed. Numerous neutron star models show that the appearance of hyperons is connected with the increasing density in neutron star interiors. The performed calculations have indicated that the change of the hyperon-hyperon coupling constants affects the chemical composition of a neutron star. The obtained numerical hyperon star models exclude large population of strange baryons in the star interior.

Dense and hot matter in compact stars and heavy-ion collisions

“…Therefore, there has to be a mechanism that suppresses (or removes) the amount of hyperons at densities relevant for compact star physics. One possibility is the vector repulsion of hyperons generated by the exchange of the φ meson [3][4][5]. This finding reinforces the point that when including hyperons as parts of the baryon octet, one should also take into account the corresponding SU(3) multiplets in the meson sector.…”

Properties of hyperonic matter in strong magnetic fields

“…The Nagara event provides unambiguous identification of 6 ΛΛ He production with a precise ΛΛ binding energy value B ΛΛ = 7.25 ± 0.19 +0.18 −0.11 MeV, which suggests that the effective ΛΛ interaction should be considerably weaker (△B ΛΛ ≃ 1 MeV) than that deduced from the earlier measurement (△B ΛΛ ≃ 4-5 MeV). The weak hyperonhyperon (Y Y ) interaction suggested by the Nagara event has been used to reinvestigate the properties of multistrange systems, and it has been found that the change of Y Y interactions affects the properties of strange hadronic matter dramatically [29,30,31]. We would like to examine how the Y Y interaction affects the properties of hyperonic matter in the presence of strong magnetic fields.…”

“…MeV, while the strong Y Y interaction deduced from the earlier measurement suggests U (Λ) Λ ≃ −20 MeV[27,29,30,31]. In…”

Properties of a protoneutron star in effective field theory

“…MeV [25] permits the existence of additional parameter set [26] which reproduces this weaker ΛΛ interaction. In the text this parameter set is marked as weak, whereas strong denotes the stronger ΛΛ interaction for U (Λ) Λ ≃ 20 MeV [12].…”