Transverse-momentum and event-shape dependence of D-meson flow harmonics in Pb–Pb collisions at

The elliptic and triangular flow coefficients ${v}_{2}$ and ${v}_{3}$ of prompt ${D}^{0}$, ${D}^{+}$, and ${D}^{⁎+}$ mesons were measured at midrapidity ($|y|<0.8$) in Pb–Pb collisions at the centre-of-mass energy per nucleon pair of $\sqrt{{s}_{\mathrm{NN}}}=5.02\phantom{\rule{0.25em}{0ex}}\text{TeV}$ with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decays in the transverse momentum interval $1<{p}_{T}<36\phantom{\rule{0.25em}{0ex}}\text{GeV}/c$ in central (0–10%) and semi-central (30–50%) collisions. Compared to pions, protons, and $J/\psi $ mesons, the average D-meson ${v}_{n}$ harmonics are compatible within uncertainties with a mass hierarchy for ${p}_{T}\lesssim 3\phantom{\rule{0.25em}{0ex}}\text{GeV}/c$, and are similar to those of charged pions for higher ${p}_{T}$. The coupling of the charm quark to the light quarks in the underlying medium is further investigated with the application of the event-shape engineering (ESE) technique to the D-meson ${v}_{2}$ and ${p}_{T}$-differential yields. The D-meson ${v}_{2}$ is correlated with average bulk elliptic flow in both central and semi-central collisions. Within the current precision, the ratios of per-event D-meson yields in the ESE-selected and unbiased samples are found to be compatible with unity. All the measurements are found to be reasonably well described by theoretical calculations including the effects of charm-quark transport and the recombination of charm quarks with light quarks in a hydrodynamically expanding medium.