Allbrooke, B M M, Asquith, L, Cerri, A, Chavez Barajas, C A, De Santo, A, Salvatore, F, Santoyo Castillo, I, Suruliz, K, Sutton, M R, Vivarelli, I and The ATLAS Collaboration, (2017) Measurements of top quark spin observables in tt̄ events using dilepton final states in √s=8TeV pp collisions with the ATLAS detector. Journal of High Energy Physics, 2017 (3). a113. ISSN 1126-6708

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Abstract

Measurements of top quark spin observables in tt̄ events are presented based on 20.2 fb−¹ of √s=8TeV 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 tt̄ 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.

Item Type:	Article
Schools and Departments:	School of Mathematical and Physical Sciences > Physics and Astronomy
Research Centres and Groups:	Experimental Particle Physics Research Group
Subjects:	Q Science > QC Physics
Depositing User:	Billy Wichaidit
Date Deposited:	13 Jul 2017 15:50
Last Modified:	13 Jul 2017 16:44
URI:	http://srodev.sussex.ac.uk/id/eprint/69249

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