Distributions of transverse momentum 푝ℓℓ푇 and the related angular variable 휙∗휂 of DrellΓÇôYan lepton pairs are measured in 20.3┬áfb−1 of protonΓÇôproton collisions at 푠√=8 ┬áTeV 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 protonΓÇôproton collisions at 푠√=7 ┬áTeV, 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 휙∗휂<1 the predictions from the Monte Carlo generator ResBos are generally consistent with the data within the theoretical uncertainties. However, at larger values of 휙∗휂 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 푝ℓℓ푇 while the fixed-order prediction of Dynnlo falls below the data at high values of 푝ℓℓ푇 . ResBos and the parton-shower Monte Carlo generators provide a much better description of the evolution of the 휙∗휂 and 푝ℓℓ푇 distributions as a function of lepton-pair mass and rapidity than the basic shape of the data.
|Original language||English (US)|
|Number of pages||77|
|Journal||European Physical Journal C|
|State||Published - 2016|