Nuclear modification factor of D${}^0$ mesons in PbPb collisions at $\sqrt{s_{\mathrm{NN}}}=$ 5.02 TeV

Abstract

The transverse momentum ($p_{\mathrm{t}}$) spectrum of prompt D${}^0$ mesons and their antiparticles has been measured via the hadronic decay channels D${}^0\to {\mathrm{K}}^{-}\ddot{I}{€}^{+}$ and ${\overline{\mathrm{D}}}^0\to {\mathrm{K}}^{+}\ddot{I}{€}^{-}$ in pp and PbPb collisions at a centre-of-mass energy of 5.02 TeV per nucleon pair with the CMS detector at the LHC. The measurement is performed in the D${}^0$ meson $p_{\mathrm{t}}$ range of 2-100 GeV and in the rapidity range of $|y|<$1. The pp (PbPb) dataset used for this analysis corresponds to an integrated luminosity of 27.4 pb${}^{-1}$ (530 $\hat{I}¼$b${}^{-1}$). The measured D${}^0$ meson $p_{\mathrm{t}}$ spectrum in pp collisions is well described by perturbative QCD calculations. The nuclear modification factor, comparing D${}^0$ meson yields in PbPb and pp collisions, was extracted for both minimum-bias and the 10% most central PbPb interactions. For central events, the D${}^0$ meson yield in the PbPb collisions is suppressed by a factor of 5-6 compared to the pp reference in the $p_{\mathrm{t}}$ range of 6-10 GeV. For D${}^0$ mesons in the high-$p_{\mathrm{t}}$ range of 60-100 GeV, a significantly smaller suppression is observed. The results are also compared to theoretical calculations.

Replaced with the published version. Added the journal reference. All the figures and tables, including additional supplementary figures, can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/HIN-16-001 (CMS Public Pages)