Looking for the exotic $X_0(2866)$ and its $J^P=1^+$ partner in the $\bar{B}^0 \to D^{(*)+} K^- K^{(*)0} $ reactions

Abstract

We propose two reactions, $\bar{B}^0 \to K^0 D^{+} K^-$ and $\bar{B}^0 \to K^{*0} D^{*+} K^-$, already measured at Belle, to look into the $J^P=0^+$, $X_0(2866)$ state and a $1^+$ partner of molecular $D^*\bar{K}^*$ nature, by looking at the $D^+ K^-$ and $D^{*+} K^-$ invariant mass distributions, respectively. Very clear peaks over the background are predicted and the branching ratios for the production of these states are evaluated to facilitate the task of determining the needed statistics for their observation. The fact that the $K^{*0} K^-$ mass distribution from accumulation of events of different reactions is already available, indicates that one is not far away from having the needed statistics to see peaks in the $D^{(*)+} K^-$ mass distributions, so far not yet analyzed.