A measurement of observables sensitive to spin correlations in t ¯t production is presented, using 36.1 fb−1 of pp collision data at √ s = 13 TeV recorded with the ATLAS detector at the Large Hadron Collider. Differential cross-sections are measured in events with exactly one electron and one muon with opposite-sign electric charge as a function of the azimuthal opening angle and the absolute difference in pseu...
Results are presented from the measurement by ATLAS of long-range (| η| > 2) dihadron angular correlations in √ s = 8 and 13 TeV pp collisions containing a Z boson. The analysis is performed using 19.4 fb−1 √ of s = 8 TeV data recorded during Run 1 of the LHC and 36.1 fb−1 of √ s = 13 TeV data recorded during Run 2. Two-particle correlation functions are measured as a function of relative azimuthal angle over t...
The jet energy scale, jet energy resolution, and their systematic uncertainties are measured for jets reconstructed with the ATLAS detector in 2012 using proton– proton data produced at a centre-of-mass energy of 8 TeV with an integrated luminosity of 20 fb−1. Jets are reconstructed from clusters of energy depositions in the ATLAS calorimeters using the anti-kt algorithm. A jet calibration scheme is applied in ...
Multi-particle azimuthal cumulants are measured as a function of centrality and transverse momentum using 470 μb−1 of Pb+Pb collisions at sNN = 5.02 TeV with the ATLAS detector at the LHC. These cumulants provide information on the event-by-event fluctuations of harmonic flow coefficients vn and correlated fluctuations between two harmonics vn and vm. For the first time, a non-zero four-particle cumulant is obs...
A measurement of the production of a prompt J/ψ meson in association with a W± boson with W± → μν and J/ψ → μ+μ− is presented for J/ψ transverse momenta in the range 8.5–150 GeV and rapidity |yJ/ψ| < 2.1 using ATLAS data recorded in 2012 at the LHC. The data were taken at a proton-proton centre-of-mass energy of s = 8 TeV and correspond to an integrated luminosity of 20.3 fb−1. The ratio of the prompt J/ψ plus ...
Algorithms used for the reconstruction and identification of electrons in the central region of the ATLAS detector at the Large Hadron Collider (LHC) are presented in this paper; these algorithms are used in ATLAS physics analyses that involve electrons in the final state and which are based on the 2015 and 2016 proton–proton collision data produced by theLHCat √ s = 13TeV. The performance of the electron recon...
This paper presents measurements of W±Z production cross sections in pp collisions at a centre-of-mass energy of 13 TeV. The data were collected in 2015 and 2016 by the ATLAS experiment at the Large Hadron Collider, and correspond to an integrated luminosity of 36.1fb-1. The W±Z candidate events are reconstructed using leptonic decay modes of the gauge bosons into electrons and muons. The measured inclusive cro...
The top quark mass is measured using a template method in the tt¯ → lepton + jets channel (lepton is e or μ) using ATLAS data recorded in 2012 at the LHC. The data were taken at a proton–proton centre-of-mass energy of s=8 TeV and correspond to an integrated luminosity of 20.2 fb - 1 . The tt¯ → lepton + jets channel is characterized by the presence of a charged lepton, a neutrino and four jets, two of which or...