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, ∆φ, with respect to the elliptic event plane provide insight into the path-length dependence of jet quenching. ATLAS has measured the ∆φ 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 ∆φ was characterized by the parameter, v jet 2 , and the ratio of out-of-plane (∆φ ∼ π/2) to in-plane (∆φ ∼ 0) yields. Non-zero v jet 2 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.