Abstract
Abstract:
The elliptic flow of prompt and non-prompt J/ψ was measured in the dimuon decay channel
in Pb+Pb collisions at √s
= 5.02 TeV with an integrated luminosity of 0.42 nb−1 with
the ATLAS detector at the LHC. The prompt and non-prompt signals are separated using a
two-dimensional simultaneous fit of the invariant mass and pseudo-proper decay time of the dimuon
system from the J/ψ decay. The measurement is performed in the kinematic range of dimuon transverse
momentum and rapidity 9 < pT < 30 GeV, |y| < 2, and 0–60% collision centrality. The elliptic flow
coefficient, v2, is evaluated relative to the event plane and the results are presented as a
function of transverse momentum, rapidity and centrality. It is found that prompt and non-prompt
J/ψ mesons have non-zero elliptic flow. Prompt J/ψ v2 decreases as a function of pT, while for
non-prompt J/ψ it is, with limited statistical significance, consistent with a flat behaviour over
the studied kinematic region. There is no
observed dependence on rapidity or centrality.