Charmonium in nuclear matter and nuclei

TL;DR

This paper investigates the potential for $ ext{eta}_c$ mesons to form bound states within various nuclei using an effective Lagrangian approach, indicating such states are likely across different nuclear targets.

Contribution

It introduces a novel calculation of $ ext{eta}_c$-nucleus bound states considering medium modifications via an effective Lagrangian and local density approximation.

Findings

$ ext{eta}_c$ can form bound states with all studied nuclei.

Medium modifications of the $D D^{*}$ state are crucial for binding.

Results support the existence of $ ext{eta}_c$-nucleus bound states.

Abstract

We present results for the $\eta_c$-nucleus bound state energies for various nuclei using an effective Lagrangians approach. The attractive potentials for the $\eta_c$ in the nuclear medium originate from the medium-modified intermediate $D D^{*}$ state in the $\eta_c$ self energy, using the local density approximation. Our results suggest that the $\eta_c$ should form bound states with all the nuclei considered