Possibility ofΛΛpairing and its dependence on background density in a relativistic Hartree-Bogoliubov model

Abstract

We calculate a ΛΛ pairing gap in binary mixed matter of nucleons and Λ hyperons within the relativistic Hartree-Bogoliubov model. Lambda hyperons to be paired up are immersed in background nucleons in a normal state. The gap is calculated with a one-boson-exchange interaction obtained from a relativistic Lagrangian. It is found that at background density ρN = 2.5ρ0 the ΛΛ pairing gap is very small, and that denser background makes it rapidly suppressed. This result suggests a mechanism, specific to mixed matter dealt with relativistic models, of its dependence on the nucleon density. An effect of weaker ΛΛ attraction on the gap is also examined in connection with revised information of the ΛΛ interaction.

Hyperons in hot dense matter: what do the constraints tell us for equation of state?

“…However, the superfluid hyperon gap is strongly dependent on the hyperon properties in neutron star matter and on the YY interaction (Wang & Shen 2010). In particular, it has been shown the small value of B obtained from 6 He (Takahashi et al 2001) leads to a very small gap in dense neutron matter (Tanigawa, Matsuzaki, & Chiba 2003) and in dense neutron star matter (Wang & Shen 2010) or even suppresses completely the superfluidity. Following Wang & Shen (2010), superfluidity exists in massive neutron stars only for strong interactions.…”

ΛΛ pairing in multistrange hypernuclei

“…In the following, we will therefore calibrate our ΛΛ pairing interaction on hypernuclear matter pre-dictions of Ref. [23], which represents an average prediction for the maximum possible Λ pairing gap.…”

“…Fermi momenta corresponding to these densities are calculated as k FΛ = ( 3π 2 2 ρ Λ ) 1/3 . The density profile of hypernuclear matter calculations [23] which has corresponding Fermi momentum and density fraction allows to extract ΛΛ pairing gap for each hypernuclei for each force sets. For finding adequate Λ pairing strength (V Λpair in Eq.…”

Double- Hypernuclei in the Relativistic Mean-Field Theory

“…15)-18) It has also been used to examine the properties of strange hadronic matter. 5), 19)- 21) The purpose of this paper is to present a self-consistent calculation of double-Λ hypernuclei in a wide range of mass number A within the framework of relativistic mean-field theory (RMF), and also to examine possible contributions of the two strange mesons σ * and φ to the ΛΛ binding energy. In principle, exact few-body calculations are more appropriate for light hypernuclei, but they are not available for heavy systems.…”