$\Upsilon$ and $\eta_b$ nuclear bound states

Abstract

$\Upsilon$ and $\eta_b$ nuclear bound state energies are calculated for various nuclei neglecting any possible effects of the widths. Essential input for the calculations, namely the medium-modified $B$ and $B^{*}$ meson masses, as well as the density distributions in nuclei, are calculated within the quark-meson coupling (QMC) model. The attractive potentials for the $\Upsilon$ and $\eta_b$ mesons in nuclei are calculated from the mass shifts of these mesons in nuclear matter in the local density approximation. These potentials originate from the in-medium enhanced $B\overline{B}$ and $BB^{*}$ loops in their respective self energy. After an extensive analysis we conclude that our results suggest that the $\Upsilon$ and $\eta_b$ mesons should form bound states with all the nuclei considered.