Lead ion collision event in CERN's CMS detector. Computer-generated graphic of the results of a collision between lead ions (PbPb collision), as observed by the CMS (Compact Muon Solenoid) detector of the Large Hadron Collider (LHC) at CERN, the European particle physics laboratory. During this event, a candidate Z boson decayed into two electrons (shown by the green line and green tower) and a jet (shown by the orange cone). The Z candidate and the jet are nearly back-to-back. This experiment took place on 12 November 2018.