$B_c, B^{*}_c, B_s, B^{*}_s, D_s$ and $D^{*}_s$ mass shift in a nuclear medium

TL;DR

This study estimates the in-medium mass shifts of various heavy mesons in symmetric nuclear matter using one-loop self-energy calculations, revealing significant negative shifts influenced mainly by lighter vector meson excitations.

Contribution

First estimation of in-medium mass shifts for multiple heavy mesons using one-loop self-energy evaluations in nuclear matter.

Findings

Mass shifts are negative for all studied mesons.

The $B_c$ meson exhibits a larger mass shift than expected, differing from naive predictions.

Lighter vector meson excitations dominate the mass shift contributions.

Abstract

For the first time, we estimate the in-medium mass shift of the two-flavored heavy mesons $B_c, B_c^*, B_s, B_s^*, D_s$ and $D_s^*$ in symmetric nuclear matter. The estimates are made by evaluating the lowest order one-loop self-energies. The enhanced excitations of intermediate state heavy-light quark mesons in symmetric nuclear matter are the origin of their negative mass shift. Our results show that the magnitude of the mass shift for the $B_c$ meson ($\bar{b} c$ or $b \bar{c}$) is larger than those of the $\eta_c (\bar{c} c)$ and $\eta_b (\bar{b} b)$, different from a naive expectation that it would be in-between of them. While, that of the $B_c^*$ shows the in-between of the $J/\psi$ and $\Upsilon$. We observe that the lighter vector meson excitation in each meson self-energy gives a dominant contribution for the corresponding meson mass shift, $B_c, B_s,$ and $D_s$.