Measurement of non-prompt D0-meson elliptic flow in Pb–Pb collisions at √sNN = 5.02 TeV

Abstract

t The elliptic flow (v2) of D0 mesons from beautyhadron decays (non-prompt D0) was measured in midcentral (30–50%) Pb–Pb collisions at a centre-of-mass energy per nucleon pair √sNN = 5.02 TeV with the ALICE detector at the LHC. The D0 mesons were reconstructed at midrapidity (|y| < 0.8) from their hadronic decay D0 → K−π+, in the transverse momentum interval 2 < pT < 12 GeV/c. The result indicates a positive v2 for non-prompt D0 mesons with a significance of 2.7σ. The non-prompt D0-meson v2 is lower than that of prompt non-strange D mesons with 3.2σ significance in 2 < pT < 8 GeV/c, and compatible with the v2 of beauty-decay electrons. Theoretical calculations of beautyquark transport in a hydrodynamically expanding medium describe the measurement within uncertainties.