Elliptic and triangular flow of (anti)deuterons in Pb-Pb collisions at sNN =5.02 TeV

Abstract

The measurements of the (anti)deuteron elliptic flow (${v}_{2}$) and the first measurements of triangular flow (${v}_{3}$) in Pb-Pb collisions at a center-of-mass energy per nucleon-nucleon collision $\sqrt{{s}_{\mathrm{NN}}}$ = 5.02 TeV are presented. A mass ordering at low transverse momentum (${p}_{\mathrm{T}}$) is observed when comparing these measurements with those of other identified hadrons, as expected from relativistic hydrodynamics. The measured (anti)deuteron ${v}_{2}$ lies between the predictions from the simple coalescence and blast-wave models, which provide a good description of the data only for more peripheral and for more central collisions, respectively. The mass number scaling, which is violated for ${v}_{2}$, is approximately valid for the (anti)deuterons ${v}_{3}$. The measured ${v}_{2}$ and ${v}_{3}$ are also compared with the predictions from a coalescence approach with phase-space distributions of nucleons generated by iebe-vishnu with ampt initial conditions coupled with urqmd, and from a dynamical model based on relativistic hydrodynamics coupled to the hadronic afterburner smash. The model predictions are consistent with the data within the uncertainties in midcentral collisions, while a deviation is observed in the most central collisions.