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

TL;DR

This paper analyzes the $B^+ o J/ aupsi \omega K^+$ reaction, revealing that two molecular resonances, $X(3940)$ and $X(3930)$, influence the observed mass distribution, including a peak and a cusp at the $D^* ar{D}^*$ threshold.

Contribution

It demonstrates that the $X(3940)$ and $X(3930)$ resonances are molecular states strongly coupled to $D^* ar{D}^*$ and $J/ aupsi\omega$, explaining features in the mass distribution.

Findings

Identification of $X(3940)$ and $X(3930)$ as molecular states.

Observation of a peak and cusp in the $J/ aupsi\omega$ mass distribution.

Resonances strongly couple to $D^* ar{D}^*$ and $J/ aupsi\omega$ channels.

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 $D^* \bar{D}^*$, 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 $D^* \bar{D}^*$ threshold.