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, (2018) Measurement of τ polarisation in Z/γ∗ → ττ decays in proton–proton collisions at √s = 8 TeV with the ATLAS detector. European Physical Journal C: Particles and Fields, 78 (163). ISSN 1434-6044
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Abstract
This paper presents a measurement of the polarisation of τ leptons produced in Z/γ ∗ → ττ decays which is performed with a dataset of proton—proton collisions at √s = 8 TeV, corresponding to an integrated luminosity of 20.2 fb−1 recorded with the ATLAS detector at the LHC in 2012. The Z/γ∗ → ττ decays are reconstructed from a hadronically decaying τ lepton with a single charged particle in the final state, accompanied by a τ lepton that decays leptonically. The τ polarisation is inferred from the relative fraction of energy carried by charged and neutral hadrons in the hadronic τ decays. The polarisation is measured in a fiducial region that corresponds to the kinematic region accessible to this analysis. The τ polarisation extracted over the full phase space within the Z/γ∗ mass range of 66 < mZ/γ∗ < 116GeV is found to be Pτ = −0.14±0.02(stat)±0.04(syst). It is in agreement with the Standard Model prediction of Pτ = −0.1517 ± 0.0019, which is obtained from the ALPGEN event generator interfaced with the PYTHIA 6 parton shower modelling and the TAUOLA τ decay library.
Item Type: | Article |
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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: | 25 May 2018 08:45 |
Last Modified: | 09 Jul 2021 08:32 |
URI: | http://sro.sussex.ac.uk/id/eprint/76110 |
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📧 Request an updateProject Name | Sussex Project Number | Funder | Funder Ref |
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ATLAS | G0275 | STFC-SCIENCE AND TECHNOLOGY FACILITIES COUNCIL | ST/I006048/1 |