Hard physics with heavy ions in CMS

Abstract

The LHC will collide protons at √s = 14 TeV and lead beams at √sNN = 5.5 TeV as well as possibly other AA and pA combinations. The physics program of the Compact Muon Solenoid (CMS) includes the study of heavy-ion collisions, where the collision energy, higher than at RHIC, will allow the study of the dense partonic system with hard probes. A broad palette of these probes is within the reach of CMS. Some are likely to be modified, relative to p-p collisions, by the presence of the hot medium, like quarkonia (J/ψ and γ) or high-pT jets. Others, like heavy quarks, Z0 bosons and photons, will act as reference candles. This article overviews the hard physics reach and unique abilities of CMS in studying the medium produced in heavy-ion collisions at the LHC.