D meson nuclear modification factors in Pb-Pb collisions at sqrt(s_NN) = 2.76 TeV with the ALICE detector

TL;DR

This paper reports on measurements of D meson production in Pb-Pb collisions at 2.76 TeV, revealing significant suppression at high transverse momentum, which tests models of parton energy loss in quark-gluon plasma.

Contribution

It provides the first measurements of D^(+)_(s) nuclear modification factors and extends the pT range for D meson suppression studies in heavy-ion collisions.

Findings

Observed a suppression factor of 3 to 4 for pT > 5 GeV/c in central collisions.

First measurement of D^(+)_(s) nuclear modification factor.

Extended pT range for D meson suppression analysis.

Abstract

The measurement of D meson production provides key tests for parton energy-loss models, which predict that charm quarks should experience less in-medium energy loss than light quarks and gluons. The ALICE experiment has measured the production of prompt D^(0), D^(+) and D^(*+) mesons in pp and Pb-Pb collisions at the LHC at sqrt(s) = 7 and 2.76 TeV and at sqrt(s_NN) = 2.76 TeV, respectively, via the exclusive reconstruction of their hadronic decay. The pT-differential production yields in the range 2 < pT < 16 GeV/c at central rapidity, |y| < 0.5, were used to calculate the nuclear modification factor. A suppression of a factor 3 to 4 for transverse momenta larger than 5 GeV/c in the 20% most central collisions was observed. Preliminary results in an extended pT-range, using the data sample collected during the 2011 Pb-Pb run, together with the first measurement of D^(+)_(s) nuclear modification factor will be shown.