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

Sessions: Heavy Ions The Large Hadron Collider at CERN will collide lead ions at $\sqrt{S_{NN}}=5.5$ TeV allowing high statistics studies of the dense partonic system with hard probes: heavy quarks and quarkonia with an emphasis on the $b$ and $\Upsilon$, $high-p_T$ jets, photons, as well as $Z^0$ 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 $p_T$ redistribution of particles within the jet. The large CMS acceptance will allow detailed studies of jet structure in rare $\gamma-jet$ and Z-jet events. The high resolution tracker will tag $b$ quark jets. The muon chambers combined with tracking will study production of the $Z^0$, $J/\psi$ and the $\Upsilon$ 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.