Hidden beauty baryon states in the local hidden gauge approach with heavy quark spin symmetry

Abstract

Using a coupled channel unitary approach, combining the heavy quark spin symmetry and the dynamics of the local hidden gauge, we investigate the meson-baryon interaction with hidden beauty and obtain several new states of $N^*$ around 11 GeV. We consider the basis of states $\eta_b N$, $\Upsilon N$, $B \Lambda_b$, $B \Sigma_b$, $B^* \Lambda_b$, $B^* \Sigma_b$, $B^* \Sigma_b^*$ and find four basic bound states which correspond to $B \Sigma_b$, $B \Sigma_b^*$, $B^* \Sigma_b$ and $B^* \Sigma_b^*$, decaying mostly into $\eta_b N$ and $\Upsilon N$ and with a binding energy about 50-130 MeV with respect to the thresholds of the corresponding channel. All of them have isospin $I=1/2$, and there are no bound states or resonances in $I=3/2$. The $B \Sigma_b$ state appears in $J=1/2$, the $B \Sigma_b^*$ in $J=3/2$, the $B^* \Sigma_b$ appears nearly degenerate in $J=1/2, ~3/2$ and the $B^* \Sigma_b^*$ appears nearly degenerate in $J=1/2, ~3/2, ~5/2$. These states have a width from $6 \sim 45 \mev$ except for the one in $J=5/2$ which has zero width since it cannot decay into any of the states of the basis chosen.