Speaker
Alessandro Grelli
(University of Utrecht (NL))
Description
The properties of the hot and dense QCD medium formed in ultra-relativistic heavy-ion
collisions, as well as the mechanism of in-medium partonic energy loss, can be
accessed via the measurement of the nuclear modification factor of particle
production. The measurement of D meson production provides key tests of parton
energy-loss models, which predict that charm quarks should experience less in-medium energy loss than light quarks and gluons. Moreover if in-medium
hadronization is the dominant mechanism of charm hadron formation at low p_{T} then
the production of charm strange hadrons, like D_{s}^{+}, is expected to be largely enhanced. Finally the elliptic flow v2 of D meson compared to that of light hadrons is expected to bring insights into the degree of thermalization of charm quarks within the quark gluon plasma.
The ALICE experiment has measured the production of prompt D^{0}, D^{+} and D^{*+} and D^{+}_{s} mesons in pp and Pb-Pb collisions at the LHC at √s = 7 and 2.76 TeV and at √s_{NN} = 2.76 TeV, respectively, via the exclusive reconstruction of their hadronic decay. The p_{T}-differential production yields in the range 1 < p_{T} < 36 GeV/c (4<pT<12 GeV/c in the case of D^{+}_{s}) at central rapidity, |y| < 0.5, were used to calculate the nuclear modification factor. A suppression of a factor 4-5 for p_{T} ≥ 10 GeV/c in the 7.5% most central collisions was observed. The measurement of the D meson elliptic flow in semi-central (30-50%) Pb-Pb collisions will be presented.
Author
Alessandro Grelli
(University of Utrecht (NL))
