Meson-nucleus bound states in quark meson coupling model

TL;DR

This paper investigates the formation of meson-nucleus bound states for K, D, and B mesons using the quark meson coupling model, highlighting the potential for deeply bound B-mesic states as probes of nuclear medium effects.

Contribution

It extends the quark meson coupling model to predict meson-nucleus bound states, including Coulomb effects, and identifies B-mesic states as promising for experimental detection.

Findings

Deeply bound B-mesic states are predicted at nuclear centers.

D and K mesons form less deeply bound states.

Results are relevant for upcoming experimental searches.

Abstract

The formations of the $K(\bar{K})$, $D(\bar{D})$, and $B(\bar{B})$ meson-nucleus bound states in ${\rm{^{16}O}}$, ${\rm{^{40}Ca}}$, ${\rm{^{90}Zr}}$, ${\rm{^{197}Au}}$, and ${\rm{^{208}Pb}}$ nucleus are investigated using the quark meson coupling model. The model relies on a mean field description of non-overlapping nucleon bags bound by the self-consistent interactions of scalar ($\sigma$, $\delta$) and vector ($\omega$, $\rho$) mesons with the (anti)quarks inside the bags, which is further extended to explore the properties of nuclei. We estimate the meson-nucleus bound state energies by solving the Klein-Gordon equations with the real potentials calculated self-consistently within the model, using a coordinate space approach. The calculations are carried out for different nuclear interactions. The effects of Coulomb interaction are considered in the present study for the charged mesons. Our study indicates the formation of rather deeply bound $B$-mesic states at the very central region of the nuclei, compared to the $D$ and $K$ mesons, offering a more promising probe to explore subtle nuclear medium effects. The investigations of such bound states are of particular interest for the upcoming $\rm{\bar{P}ANDA}$ at FAIR, J-PARC-E29, and JLab experiments.