The ALICE experiment at LHC: physics prospects and detector design

ALICE (A Large Ion Collider Experiment) is a dedicated detector designed to exploit the unique physics opportunities which will be offered by nucleus–nucleus collisions at the LHC. At the LHC, it will be possible to explore a radically new regime of matter, stepping up by a large factor in both volume and energy density from the nuclear interactions studied at the SpS and at RHIC. Thanks to the huge number of secondaries produced, it will be possible to measure most of the relevant variables on an event–by–event basis. The LHC energy and luminosity will allow the full spectroscopy of the Y family and of D and B mesons. ALICE is conceived as a general–purpose detector, in which most of the hadrons, leptons and photons produced in the interaction can be measured and identified. The baseline design consists of a central (|η |≤ 0.9) detector covering the full azimuth and a forward (2.4 ≤ η ≤ 4) muon arm, complemented by a forward magnetic spectrometer to study vector meson production, a multiplicity detector covering the forward rapidity region (up to |η|=4.5) and a zero degree calorimeter. The central detector will be embedded in large magnet with a weak field of 0.2T, and will consist of a high–resolution inner tracking system, a cylindrical time projection chamber, particle identification arrays (time of flight and ring imaging cerenkov detectors), a transition radiation detector for electron identification and a single–arm electromagnetic calorimeter.