A study of $J/\psi$ mass shift and bound states: Impact of $D D$ and $DD^*$ meson loops

TL;DR

This paper studies how the mass of the $J/ar{psi}$ meson shifts in nuclear matter due to meson loop effects, suggesting possible bound states and providing results relevant for upcoming experimental investigations.

Contribution

It introduces a combined approach using effective Lagrangians, chiral models, and QCD sum rules to analyze $J/ar{psi}$ mass modifications and bound states in nuclear environments.

Findings

Mass of $J/ar{psi}$ decreases with increasing baryonic density.

$J/ar{psi}$ can form bound states within nuclei.

Calculated binding energies and decay widths for various nuclei.

Abstract

We investigate the modification of the $J/\psi$ meson mass in asymmetric nuclear matter at zero and finite temperatures employing an effective Lagrangian approach that considers the contributions of $DD$ and $DD^*$ meson loops. The medium dependence of $D$ meson masses is determined using the hadronic chiral SU(3) model, where scalar condensates are calculated and subsequently utilized in the QCD sum rules approach. Our findings indicate that an increase in baryonic density results in a negative mass shift of the $J/\psi$ meson. This suggests that the $J/\psi$ meson is attracted to nuclear mean fields indicating the possibility of the formation of meson-nucleus bound states. Moreover, we have also determined the binding energy and absorption decay width of the $J/\psi$ meson for both the ground and excited states of $\text{O}^{16}$, $\text{Ca}^{40}$, $\text{Zr}^{90}$, and $\text{Pb}^{208}$ nuclei. These results are expected to contribute to the understanding of experimental data from upcoming studies at Jefferson lab and the facility for antiproton and ion research, where low-momentum charmed mesons can be produced and examined within nuclei.