Aad, G;
Abbott, B;
Abbott, DC;
Abed Abud, A;
Abeling, K;
Abhayasinghe, DK;
Abidi, SH;
... et al, .; + view all
(2020)
Combination of the W boson polarization measurements in top quark decays using ATLAS and CMS data at \sqrt{s} = 8 TeV.
Journal of High Energy Physics
, 2020
(8)
, Article 51. 10.1007/JHEP08(2020)051.
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Abstract
The combination of measurements of the W boson polarization in top quark decays performed by the ATLAS and CMS collaborations is presented. The measurements are based on proton-proton collision data produced at the LHC at a centre-of-mass energy of 8 TeV, and corresponding to an integrated luminosity of about 20 fb^{-1} for each experiment. The measurements used events containing one lepton and having different jet multiplicities in the final state. The results are quoted as fractions of W bosons with longitudinal (F_{0}), left-handed (F_{L}), or right-handed (F_{R}) polarizations. The resulting combined measurements of the polarization fractions are F0 = 0.693 ± 0.014 and FL = 0.315 ± 0.011. The fraction F_{R} is calculated from the unitarity constraint to be F_{R} = −0.008 ± 0.007. These results are in agreement with the standard model predictions at next-to-next-to-leading order in perturbative quantum chromodynamics and represent an improvement in precision of 25 (29)% for F_{o} (F_{L}) with respect to the most precise single measurement. A limit on anomalous right-handed vector (VR), and left- and right-handed tensor (g_{L}, g_{R})tWb couplings is set while fixing all others to their standard model values. The allowed regions are [−0.11, 0.16] for V_{R}, [−0.08, 0.05] for g_{L}, and [−0.04, 0.02] for g_{R}, at 95% confidence level. Limits on the corresponding Wilson coefficients are also derived.
| Type: | Article |
|---|---|
| Title: | Combination of the W boson polarization measurements in top quark decays using ATLAS and CMS data at \sqrt{s} = 8 TeV |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1007/JHEP08(2020)051 |
| Publisher version: | https://doi.org/10.1007/JHEP08(2020)051 |
| Language: | English |
| Additional information: | © 2020 Springer Nature Switzerland AG. This article is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/). |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10109136 |
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