The $X(6900)$ peak could be a molecular state

Abstract

The analyses of the LHCb data on $X(6900)$ found in di-$J/\ddot{I}ˆ$ and $J/\ddot{I}ˆ\ddot{I}ˆ(3686)$ systems are performed using a momentum-dependent {Flatté}-like parameterization. The use of the pole counting rule and spectral density function sum rule give consistent conclusions that $X(6900)$ may not be a molecule of $J/\ddot{I}ˆ\ddot{I}ˆ(3686)$. Nevertheless it is still possible that $X(6900)$ be a molecule of higher states, such as $J/\ddot{I}ˆ\ddot{I}ˆ(3770)$, $\ddot{I}{‡}_{c0}\ddot{I}{‡}_{c2}$, etc.

7pages with 9 figures