Looking for the exotic X0 (2866) and its JP=1+ partner in the B ¯ 0 →d (∗)+K-K (∗)0 reactions

Abstract

We propose two reactions, B¯0→K0D+K- and B¯0→K∗0D∗+K-, which have been already measured at Belle, to look into the JP=0+, X0(2866) state and a 1+ partner of molecular D∗K̄∗ 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. We conclude that with the upgrade of Belle II clear peaks should be seen in both reactions for the two resonances discussed.