Transverse momentum dependence of D meson production in Pb-Pb collisions at sqrt(s_NN) = 2.76 TeV

Submission Date: 
23/09/2015
Article Information
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System: 
Pb-Pb
Energy: 
2.76 TeV
Abstract Plain Text: 

The production of prompt charmed mesons $\Dzero$, $\Dplus$ and $\Dstar$, and their antiparticles, was measured with the ALICE detector in $\PbPb$ collisions at centre-of-mass energy per nucleon pair, $\sqrtsNN$, of~$2.76~\TeV$. The production yields of D mesons with rapidity $|y|<0.5$ is presented as a function of transverse momentum, $\pt$, in the interval 1--36~$\gevc$ for the centrality class 0--10\% and in the interval 1--16~GeV/$c$ for the centrality class 30--50\%. The nuclear modification factor $\Raa$ was computed using a proton--proton reference at $\sqrts = 2.76~\TeV$, obtained from measurements at $\sqrts = 7~\TeV$ and from theoretical calculations.  A maximum suppression by a factor of 5--6 with respect to binary-scaled pp yields is observed in the most central collisions at $\pt \sim 10~\gevc$. A suppression of a factor of about 2--3 persists
at the highest $\pt$ covered by the measurements. At low $\pt$ (1--3~GeV/$c$), the $\Raa$ has large uncertainties that span the range 0.35 (factor of 3 suppression) to 1 (no suppression).
In all $\pt$ intervals, the $\Raa$ is larger when going to
the 30--50\% centrality class. The D-meson nuclear modification factor is compared to the one obtained in $\pPb$ collisions at  $\sqrtsNN=5.02~\TeV$, confirming that the measured suppression comes from final state effects for $\pt > 3~\gev/c$. The D-meson $\Raa$ is compared also with that of charged pions and, at large $\pt$, charged hadrons, as well as with model calculations.