CMS looks for evidence of J/ψ mesons in near-collision events in the LHC’s 2011 heavy-ion run, during which lead nuclei were accelerated to an unprecedented energy of 574 trillion electronvolts.
J/psi
CDF observes approximately 740 events in the muon decay mode. CDF looked for a signature of three muons, the mass of two oppositely charged muons being consistent with that of the J/ψ particle.