PHYSICS CAPABILITIES OF THE ATLAS EXPERIMENT IN Pb plus Pb COLLISIONS AT THE LHC

Relativistic heavy ion collisions at the LHC will uncover properties of a hot and dense medium formed at a collision energy thirty times larger than the energy presently available at RHIC. ATLAS is one of the three experiments participating in the heavy ion program at the LHC. A brief overview of the variety of observables which will be measured by ATLAS to study soft and hard QCD phenomena in heavy ion environment is presented. In particular the detector will measure global observables like charged particle multiplicity, azimuthal anisotropy and energy flow. The detector provides also an excellent capability to probe the quark gluon plasma by measurement of high energy jets and photons as well as quarkonia states. Performance of a high granularity calorimeter, silicon tracking detector and muon spectrometer in heavy ion collisions is reported. The unique ATLAS potential to study Pb+Pb interactions is discussed.