Nuclear modification factor of D⁰ mesons in PbPb collisions at s_NN=5.02TeV

The transverse momentum (p_T) spectrum of prompt D⁰ mesons and their antiparticles has been measured via the hadronic decay channels D⁰→K⁻π⁺ and D‾⁰→K⁺π⁻ 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 D⁰ meson p_T range of 2–100GeV/c 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 μb⁻¹). The measured D⁰ meson p_T spectrum in pp collisions is well described by perturbative QCD calculations. The nuclear modification factor, comparing D⁰ meson yields in PbPb and pp collisions, was extracted for both minimum-bias and the 10% most central PbPb interactions. For central events, the D⁰ meson yield in the PbPb collisions is suppressed by a factor of 5–6 compared to the pp reference in the p_T range of 6–10GeV/c. For D⁰ mesons in the high-p_T range of 60–100GeV/c, a significantly smaller suppression is observed. The results are also compared to theoretical calculations.