CMS Experiment at LHC: Detector Status and Physics Capabilities in Heavy Ion Collisions

Abstract

The Large Hadron Collider at CERN will collide lead ions at √ SNN = 5.5 TeV allowing high statistics studies of the dense partonic system with hard probes: heavy quarks and quarkonia with an emphasis on the b and Υ, high-pT jets, photons, as well as Z0 bosons. The Compact Muon Solenoid (CMS) detectors will allow a wide range of unique measurements in nuclear collisions. The CMS data acquisition system, with its reliance on a multipurpose, high-level trigger system, is uniquely qualified for efficient triggering in high-multiplicity heavy ion events. The excellent calorimeters combined with tracking will allow detailed studies of jets, particularly medium effects on the jet fragmentation function and the energy and pT redistribution of particles within the jet. The large CMS acceptance will allow detailed studies of jet structure in rare γ− jet and Z-jet events. The high resolution tracker will tag b quark jets. The muon chambers combined with tracking will study production of the Z0 , J/ψ and the Υ family in the central rapidity region of the collision. In addition to the detailed studies of hard probes, CMS will measure charged multiplicity, energy flow and azimuthal asymmetry event-by-event.