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. This event displayed large azimuthal anisotropy, visible in the tracks (yellow lines) and calorimeter energy deposits (green towers). This experiment took place on 12 November 2018.