First Results from Pb+Pb Collisions at the LHC

Abstract

At the end of 2010, the Large Hadron Collider (LHC) at CERN started operation with heavy-ion beams, colliding lead nuclei at a center-of-mass energy of 2.76 TeV per nucleon. These collisions ushered in a new era in ultrarelativistic heavy-ion physics at energies exceeding that of previous accelerators by more than an order of magnitude. This review summarizes the results from the first year of heavy-ion physics at the LHC obtained by the three experiments participating in the heavy-ion program: ALICE, ATLAS, and CMS.