The Inner Tracking System (ITS) is the detector of the ALICE central barrel located closest to the beam axis and it is therefore a key detector for tracking and vertexing performance. Here, the main results from the ITS commissioning with atmospheric
muons in 2008 are presented, focusing in particular on the detector operation and calibration and on the methods developed for the alignment of the ITS detectors using reconstructed tracks.
The J/$psi$ azimuthal distribution relative to the reaction plane has been measured by the NA50 experiment in Pb-Pb collisions at 158 GeV/nucleon. Various physical mechanisms related to charmonium dissociation in the medium created in the heavy ion c
ollision are expected to introduce an anisotropy in the azimuthal distribution of the observed J/$psi$ mesons at SPS energies. Hence, the measurement of J/$psi$ elliptic anisotropy, quantified by the Fourier coefficient v$_2$ of the J/$psi$ azimuthal distribution relative to the reaction plane, is an important tool to constrain theoretical models aimed at explaining the anomalous J/$psi$ suppression observed in Pb-Pb collisions. We present the measured J/$psi$ yields in different bins of azimuthal angle relative to the reaction plane, as well as the resulting values of the Fourier coefficient v$_{2}$ as a function of the collision centrality and of the J/$psi$ transverse momentum. The reaction plane has been estimated from the azimuthal distribution of the neutral transverse energy detected in an electromagnetic calorimeter. The analysis has been performed on a data sample of about 100 000 events, distributed in five centrality or p$_{rm T}$ sub-samples. The extracted v$_{2}$ values are significantly larger than zero for non-central collisions and are seen to increase with p$_{rm T}$.
