Effects of many-body interactions in hypernuclei with Korea-IBS-Daegu-SKKU functionals

Abstract

© 2022, The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature.We investigate the properties of Λ hyperon in Λ -hypernuclei using an effective nuclear density functional theory which is based on the low-energy effective field theory. It expands the energy density in the power of Fermi momentum, and consequently has multiple density dependence for the effective many-body interactions. Starting from the effective density functional for nucleons, we determine the parameters for the two- and many-body Λ -N interactions added to the nucleon energy density functional by fitting to Λ -hypernuclear data. The experimental data consist of the energy levels of a Λ hyperon in the p-, and d-states as well as s-state of Λ -hypernuclei in the mass range from Λ16O to Λ208Pb. The results turn out to properly explain the data relevant to hypernuclei owing to the effective many-body interaction apart from a few data in light hypernuclei. This hyperon functional is applied to study the Λ hyperon binding energy of the neutron-rich Λ124-136Sn isotopes which are under consideration for the measurement at J-PARC. Our results are shown to be insensitive to the density dependence of symmetry energy. We also examine the nuclear matter including Λ hyperon. We note that the hyperon threshold density depends on the nuclear matter properties.