Measurements of top quark spin observables in tt¯ events using dilepton final states in √s=8 TeV pp collisions with the ATLAS detector. / The ATLAS Collaboration.

In: Journal of High Energy Physics, Vol. 2017, 113, 03.2017, p. 1-50.

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Abstract

Measurements of top quark spin observables in tt¯ events are presented based on 20.2 fb−1 of √s=8 TeV proton-proton collisions recorded with the ATLAS detector at the LHC. The analysis is performed in the dilepton final state, characterised by the presence of two isolated leptons (electrons or muons). There are 15 observables, each sensitive to a different coefficient of the spin density matrix of tt¯ production, which are measured independently. Ten of these observables are measured for the first time. All of them are corrected for detector resolution and acceptance effects back to the parton and stable-particle levels. The measured values of the observables at parton level are compared to Standard Model predictions at next-to-leading order in QCD. The corrected distributions at stable-particle level are presented and the means of the distributions are compared to Monte Carlo predictions. No significant deviation from the Standard Model is observed for any observable.
Original languageEnglish
Article number113
Pages (from-to)1-50
Number of pages50
JournalJournal of High Energy Physics
Volume2017
Early online date22 Mar 2017
DOIs
Publication statusPublished - Mar 2017
This open access research output is licenced under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

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