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

The elliptic flow ( v 2 ) of D 0 mesons from beauty-hadron decays (non-prompt D 0 ) was measured in midcentral (30–50%) Pb–Pb collisions at a centre-of-mass energy per nucleon pair s NN = 5.02 TeV with the ALICE detector at the LHC. The D 0 mesons were reconstructed at midrapidity ( | y | < 0.8 ) from their hadronic decay D 0 → K - π + , in the transverse momentum interval 2 < p T < 12 GeV/ c . The result indicates a positive v 2 for non-prompt D 0 mesons with a significance of 2.7 σ . The non-prompt D 0 -meson v 2 is lower than that of prompt non-strange D mesons with 3.2 σ significance in 2 < p T < 8 GeV / c , and compatible with the v 2 of beauty-decay electrons. Theoretical calculations of beauty-quark transport in a hydrodynamically expanding medium describe the measurement within uncertainties.