Suppression of high transverse momentum D mesons in central Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV

TL;DR

This study measures the suppression of high transverse momentum D mesons in central Pb-Pb collisions at 2.76 TeV, revealing significant suppression indicative of quark-gluon plasma effects.

Contribution

First measurement of prompt D meson production and suppression at LHC energies in Pb-Pb collisions at 2.76 TeV.

Findings

D mesons are suppressed by a factor of 3-4 at high pT in central collisions.

Suppression decreases in more peripheral collisions.

Results support the presence of partonic energy loss in quark-gluon plasma.

Abstract

The production of the prompt charm mesons $D^0$, $D^+$, $D^{*+}$, and their antiparticles, was measured with the ALICE detector in Pb-Pb collisions at the LHC, at a centre-of-mass energy $\sqrt{s_{NN}}=2.76$ TeV per nucleon--nucleon collision. The $p_{\rm T}$-differential production yields in the range $2<p_{\rm T}<16$ GeV/c at central rapidity, $|y|<0.5$, were used to calculate the nuclear modification factor $R_{AA}$ with respect to a proton-proton reference obtained from the cross section measured at $\sqrt{s}=7$ TeV and scaled to $\sqrt{s}=2.76$ TeV. For the three meson species, $R_{AA}$ shows a suppression by a factor 3-4, for transverse momenta larger than 5 GeV/c in the 20% most central collisions. The suppression is reduced for peripheral collisions.