The $B^+ \to J/ψωK^+$ reaction and $D^*\bar{D}^*$ molecular states

Abstract: We study the $B⁺ \to J/\psi \omega K⁺$ reaction, measured by the LHCb collaboration, and show that it is driven by the presence of two resonances, the $X(3940)$ and $X(3930)$, that are of molecular nature and couple most strongly to $D^* \bar{D}<sup>*$, but also to $J/\psi\omega$. Because of that, in the $J/\psi\omega$ mass distribution we find a peak related to the excitation of the resonances and a cusp with large strength at the $D^* \bar{D}<sup>*$ threshold.