In-medium properties of the low-lying bottom baryons in the quark-meson coupling model

In-medium properties of the low-lying baryons are studied in the quark-meson coupling (QMC) model, focusing on the $\Sigma_b$ and $\Xi_b$ baryons. It is predicted that the Lorentz-scalar effective mass of $\Sigma_b$ becomes smaller than that of $\Xi_b$ at moderate nuclear matter density, and as the density increases, namely, $m^*_{\Sigma_b} < m^*_{\Xi_b}$, although in vacuum $m_{\Sigma_b} > m_{\Xi_b}$. We also study the effects of the repulsive Lorentz-vector potentials on the excitation energies of these bottom baryons.

K. Tsushima · 2019