$\eta$ and $\eta'$ mesons in nuclear matter and nuclei

TL;DR

This paper investigates the potential formation of $ ext{eta}$ and $ ext{eta'}$ mesic nuclei across various nuclei by calculating their bound state energies using complex optical potentials derived from nuclear matter mass shifts.

Contribution

It provides updated calculations of $ ext{eta}$ and $ ext{eta'}$ meson bound states in nuclei using the quark-meson coupling model and solving Schrödinger and Klein-Gordon equations.

Findings

$ ext{eta}$ and $ ext{eta'}$ mesons can form bound states with nuclei.

Experimental detection may be challenging due to large decay widths.

Results are applicable across a wide range of nuclei.

Abstract

We present updated and extended results for the $\eta$- and $\eta'$-nucleus bound state energies, obtained by solving the Schr\"{o}dinger and Klein-Gordon equations with complex optical potentials, for a wide range of nuclei. The $\eta$ and $\eta'$ nuclear potentials are obtained in the local density approximation from the mass shift of these mesons in nuclear matter, which is calculated within the quark-meson coupling model. Our results show that the $\eta$ and $\eta'$ mesons are expected to form mesic nuclei with all the nuclei considered. However, the signal for the formation of the $\eta$- and $\eta'$-mesic nuclei may be difficult to identify experimentally due to possible large widths.