Journal of High Energy Physics > 2016 > 2016 > 9 > 1-41
Elliptic flow of electrons from heavy-flavour hadron decays at mid-rapidity in Pb-Pb collisions at s N N = 2.76 $$ \sqrt{{\mathrm{s}}_{\mathrm{NN}}}=2.76 $$ TeV
Source
Abstract
The elliptic flow of electrons from heavy-flavour hadron decays at mid-rapidity (|y| < 0.7) is measured in Pb-Pb collisions at s N N = 2.76 $$ \sqrt{s_{\mathrm{NN}}}=2.76 $$ TeV with ALICE at the LHC. The particle azimuthal distribution with respect to the reaction plane can be parametrized with a Fourier expansion, where the second coefficient (v 2) represents the elliptic flow. The v 2 coefficient of inclusive electrons is measured in three centrality classes (0–10%, 10–20% and 20–40%) with the event plane and the scalar product methods in the transverse momentum (p T) intervals 0.5–13 GeV/c and 0.5–8 GeV/c, respectively. After subtracting the background, mainly from photon conversions and Dalitz decays of neutral mesons, a positive v 2 of electrons from heavy-flavour hadron decays is observed in all centrality classes, with a maximum significance of 5.9σ in the interval 2 < p T < 2.5 GeV/c in semi-central collisions (20–40%). The value of v 2 decreases towards more central collisions at low and intermediate p T (0.5 < p T < 3 GeV/c). The v 2 of electrons from heavy-flavour hadron decays at mid-rapidity is found to be similar to the one of muons from heavy-flavour hadron decays at forward rapidity (2.5 < y < 4). The results are described within uncertainties by model calculations including substantial elastic interactions of heavy quarks with an expanding strongly-interacting medium.
Identifiers
journal e-ISSN : | 1029-8479 |
DOI | 10.1007/JHEP09(2016)028 |
Authors
J. Adam
- Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Prague, Czech Republic
D. Adamová
- Academy of Sciences of the Czech Republic, Nuclear Physics Institute, Řež u Prahy, Czech Republic