Measurement of the transverse momentum and ϕ∗η ϕ η ∗ distributions of Drell–Yan lepton pairs in proton–proton collisions at s√=8 s = 8 TeV with the ATLAS detector

Abstract

Distributions of transverse momentum and the related angular variable of Drell–Yan lepton pairs are measured in 20.3 fb of proton–proton collisions at  TeV with the ATLAS detector at the LHC. Measurements in electron-pair and muon-pair final states are corrected for detector effects and combined. Compared to previous measurements in proton–proton collisions at  TeV, these new measurements benefit from a larger data sample and improved control of systematic uncertainties. Measurements are performed in bins of lepton-pair mass above, around and below the Z-boson mass peak. The data are compared to predictions from perturbative and resummed QCD calculations. For values of the predictions from the Monte Carlo generator RESBOS are generally consistent with the data within the theoretical uncertainties. However, at larger values of this is not the case. Monte Carlo generators based on the parton-shower approach are unable to describe the data over the full range of while the fixed-order prediction of DYNNLO falls below the data at high values of . RESBOS and the parton-shower Monte Carlo generators provide a much better description of the evolution of the and distributions as a function of lepton-pair mass and rapidity than the basic shape of the data.