ATLAS collaboration (2870 authors)Aguilar-Saavedra, Juan AntonioAmor Dos Santos, Susana PatriciaAnjos, NunoAraque, Juan PedroCantrill, RobertCarvalho, JoãoCastro, Nuno FilipeConde Muiño, PatriciaDa Cunha Sargedas De Sousa, Mario JoseFiolhais, MiguelGalhardo, BrunoGomes, AgostinhoGonçalo, RicardoJorge, PedroLopes, LourencoMachado Miguens, JoanaMaio, AméliaManeira, JoséOnofre, AntónioPalma, AlbertoPedro, RutePina, João AntonioSantos, HelenaSaraiva, JoãoSilva, JoséTavares Delgado, AdemarVeloso, FilipeWolters, Helmut2019-02-042019-02-042016-05-23http://dx.doi.org/10.1140/epjc/s10052-016-4070-4http://hdl.handle.net/10400.26/26984Distributions of transverse momentum $p_T^{\ell \ell }$ and the related angular variable $\phi ^*_\eta $ of DrellΓÇôYan lepton pairs are measured in 20.3┬áfb$^{-1}$ of protonΓÇôproton collisions at $\sqrt{s}=8$ ┬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 $\sqrt{s}=7$ ┬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 $\phi ^*_\eta < 1$ the predictions from the Monte Carlo generator ResBos are generally consistent with the data within the theoretical uncertainties. However, at larger values of $\phi ^*_\eta $ 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 $p_T^{\ell \ell }$ while the fixed-order prediction of Dynnlo falls below the data at high values of $p_T^{\ell \ell }$ . ResBos and the parton-shower Monte Carlo generators provide a much better description of the evolution of the $\phi ^*_\eta $ and $p_T^{\ell \ell }$ distributions as a function of lepton-pair mass and rapidity than the basic shape of the data.engjournal article2019-02-04