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

Abstract

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 √ˢɴɴ =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 < Pᴛ < 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 < Pᴛ < 8 GeV/c, and compatible with the v₂ of beauty-decay electrons. Theoretical calculations of beautyquark transport in a hydrodynamically expanding médium describe the measurement within uncertainties.