Observation of exotic $J/\ddot{I}ˆ\ddot{I}•$ resonant structure in diffractive processes in proton-proton collisions

Abstract

The first study of $J/\ddot{I}ˆ\ddot{I}•$ production in diffractive processes in proton-proton collisions is presented. The study is based on an LHCb dataset recorded at centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5 fb${}^{-1}$. The data disfavour a nonresonant $J/\ddot{I}ˆ\ddot{I}•$ production but are consistent with a resonant model including several resonant states observed previously only in $B^{+}\to J/\ddot{I}ˆ\ddot{I}•K^{+}$ decays. The $\ddot{I}{‡}_{c0}(4500)$ state is observed with a significance over $6\ddot{I}ƒ$ and the $\ddot{I}{‡}_{c1}(4274)$ is confirmed with a significance of more than $4\ddot{I}ƒ$.

All figures and tables, along with any supplementary material and additional information, are available at https://lbfence.cern.ch/alcm/public/analysis/full-details/1799 (LHCb public pages)