Description of the recently observed hypernucleus ${}^{15}{}_{{\Xi }^{-}}$C within a quark-meson coupling model

Abstract

We investigate within a quark-meson coupling (QMC) model, the structure of the bound ${\Xi }^{-}$ hypernucleus ${}^{15}{}_{{\Xi }^{-}}$C (${}^{14}$N + ${\Xi }^{-}$), which has been observed in a recent analysis of the KEK-E373 experiment. In the QMC model, light quarks in nonoverlapping nucleon and ${\Xi }^{-}$ bags interact self-consistently with isoscalar-scalar ($\sigma$), isoscalar-vector ($\omega$), and isovector-vector ($\rho$) mesons in the mean field approximation. The parameters of the model (quark-meson coupling constants and masses) are mostly fixed from the nuclear matter saturation properties. The QMC model closely reproduces the separation energies of the two ${\Xi }^{-}$ hyperon states in ${}^{15}{}_{{\Xi }^{-}}$C reported in the KEK-E373 analysis, and identifies their quantum numbers. We also make predictions for the cross sections for the production of the ${}^{15}{}_{{\Xi }^{-}}$C hypernuclear specta in the ($K^{-},K^{+}$) reaction on a ${}^{15}$O target within a covariant effective Lagrangian model using the ${\Xi }^{-}$ bound state spinors obtained within the same QMC model.

Comments: 17 Pages, 4 figures