Speaker
Description
Adam Matyja
on behalf of the ALICE Collaboration
Institute of Nuclear Physics PAN,
Radzikowskiego 152, 31-342 Kraków, Poland.
The ALICE experiment at LHC is dedicated to studies of the quark-gluon plasma (QGP) state, which is created in heavy-ion collisions. Neutral mesons are excellent probes for QGP formation studies. The medium-induced energy loss of particles can be investigated via the measurement of neutral meson spectra produced in heavy-ion collisions for different centrality classes as well as via neutral meson-hadron correlations. A decrease of the nuclear modification factor ($R_{\rm AA}$) is observed, increasing with the centrality of the collision. The suppression of the per-trigger yield on the away side as measured by the modification factor ($I_{\rm AA}$) shows in a similar way the evidence for parton energy loss in medium. Neutral mesons have been measured by the ALICE experiment. Photons are measured in ALICE directly in the two electromagnetic calorimeters (PHOS and EMCal), as well as via the method of photon conversion (PCM) into electron-positon pairs, where the latter are measured in the inner tracking system (ITS) and the time projection chamber (TPC). Neutral mesons are combined from photon pairs via the invariant mass technique. Results obtained in EMCal, PHOS and PCM are consistent one to the other and allow to measure the spectra of particles with high precision over a wide kinematical range. An overview of the recent results on meson production from ALICE will be shown.
