Observation of structures in the $J/\ddot{I}ˆ+\ddot{I}ˆ(2S)$ mass spectrum with the ATLAS detector

ATLAS Collaboration

A search for resonant structures in the $J/\ddot{I}ˆ+\ddot{I}ˆ$(2S) mass spectrum is performed using proton--proton collision data at $\sqrt{s}=13$ TeV, corresponding to an integrated luminosity…