Search for the $B$ meson decays with $X(3872)$ at the CMS experiment.

A study of the exotic multiquark candidate resonance $X(3872)$ is presented. The $X(3872)$ production in the decay of neutral mesons is investigated using a sample of proton-proton collisions at $\sqrt{s}=13 {TeV}$ with the CMS detector at the CERN LHC. Such measurement, combined with analogue studies of the $X(3872)$ production in charged $B$ meson decays, is fundamental to shed light on the puzzling nature of the $X(3872)$ particle and in the understanding of the QCD theory.