Transverse momentum dependence of D-meson production in Pb–Pb collisions at \(\sqrt{s_{\rm NN}}\) = 2.76 TeV

Abstract

The production of prompt charmed mesons D\)^0\), D\)^+\) and D\)^{*+}\), and their antiparticles, was measured with the ALICE detector in Pb–Pb collisions at the centre-of-mass energy per nucleon pair, \(\sqrt{s_{\rm NN}}\) of 2.76 TeV. The production yields for rapidity \(|y| < 0.5\) are presented as a function of transverse momentum, \(p_{\rm T}\), in the interval 1–36 GeV/\(c\) for the centrality class 0–10% and in the interval 1–16 GeV/\(c\) for the centrality class 30–50%. The nuclear modification factor \(R_{\rm AA}\) was computed using a proton–proton reference at \(\sqrt{s}=2.76\) TeV, based on measurements at \(\sqrt{s}=7\) TeV and on theoretical calculations. A maximum suppression by a factor of 5–6 with respect to binary-scaled pp yields is observed for the most central collisions at \(p_{\rm T}\) of about 10 GeV/\(c\), A suppression of a factor of about 2–3 persists at the highest \(p_{\rm T}\) covered by the measurements. At low \(p_{\rm T}\) (1–3 GeV/\(c\)), the \(R_{\rm AA}\) has large uncertainties that span the range 0.35 (factor of about 3 suppression) to 1 (no suppression). In all \(p_{\rm T}\) intervals, the \(R_{\rm AA}\) is larger in the 30–50% centrality class compared to central collisions. The D-meson \(R_{\rm AA}\) is also compared with that of charged pions and, at large \(p_{\rm T}\), charged hadrons, and with model calculations.