ALICE ( A Large Ion Collider Experiment )
ALICE is the one of LHC experiments dedicated to the heavy ion physics. It takes the data both from the proton-proton and from the lead-lead collisions. Our contribution to ALICE is centered on the innermost parts of the detector: the Inner Tracking System (ITS),T0 – the timing and trigger detector and Electro Magnetic Calorimeter Trigger Units. In addition to detector construction we have interests in the theoretical and phenomenological studies of ultrarelativistic heavy ion collisions. The main focus of the Finland ALICE group is on the high-pT leading particle, jets and direct photon correlation analysis. These physics topics are very important probes to understand QCD matter at high temperature.
The study of QCD matter at high temperature is of fundamental and broad interest, forming one of the pillars of nuclear physics research. Bulk QCD matter and its possible phase transitions between hadronic matter and a quark-gluon plasma (QGP), liberating of indi- vidual quarks from their nucleon ”bags” into a deconfined and thermalized form of strongly interacting matter (QGP), can be explored in the laboratory, through the collision of heavy atomic nuclei at ultra-relativistic energies. Experimental study of relativistic heavy ion col- lisions has been carried out for three decades, beginning with the Bevalac at LBNL, and continuing with the BNL AGS ,CERN SPS and BNL RHIC.
The next major experimental milestone in the field is being achieved since Nov. 2010, with the start of the heavy ion program at the LHC. The ALICE experiment is leading a role to explore the properties of QGP with more quantitative and verifiable measurements than what has been done at RHIC.