Measurement of the azimuthal angle dependence of inclusive jet yields in Pb+Pb collisions at √sNN=2.76 TeV with the ATLAS detector

Abstract

Measurements of the variation of inclusive jet suppression as a function of relative azimuthal angle, Δ, with respect to the elliptic event plane provide insight into the path-length dependence of jet quenching. ATLAS has measured the Δ dependence of jet yields in 0.14 nb-1 of √sNN=2.76 TeV Pb+Pb collisions at the LHC for jet transverse momenta pT>45 GeV in different collision centrality bins using an underlying event subtraction procedure that accounts for elliptic flow. The variation of the jet yield with Δ was characterized by the parameter, v2jet, and the ratio of out-of-plane (Δ∼π/2) to in-plane (Δ∼0) yields. Nonzero v2jet values were measured in all centrality bins for pT<160 GeV. The jet yields are observed to vary by as much as 20% between in-plane and out-of-plane directions.