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Abstract:

This paper presents a measurement of the polarisation of W bosons from tt¯ decays, reconstructed in events with one high-pT lepton and at least four jets. Data from pp collisions at the LHC were collected at s = 8 TeV and correspond to an integrated luminosity of 20.2 fb - 1 . The angle θ ∗ between the b-quark from the top quark decay and a direct W boson decay product in the W boson rest frame is sensitive to the W boson polarisation. Two different W decay products are used as polarisation analysers: the charged lepton and the down-type quark for the leptonically and hadronically decaying W boson, respectively. The most precise measurement of the W boson polarisation via the distribution of cos θ ∗ is obtained using the leptonic analyser and events in which at least two of the jets are tagged as b-quark jets. The fitted fractions of longitudinal, left- and right-handed polarisation states are F0=0.709±0.019, FL=0.299±0.015 and FR=-0.008±0.014, and are the most precisely measured W boson polarisation fractions to date. Limits on anomalous couplings of the Wtb vertex are set. © 2017, CERN for the benefit of the ATLAS collaboration.

Registro:

Documento: Artículo
Título:Measurement of the W boson polarisation in tt¯ events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLAS
Autor:Aaboud, M. et al.
Este artículo contiene 2850 autores, consultelos en el artículo en formato pdf.
Filiación: Este artículo contiene 2850 autores con sus filiaciones, consultelas en el artículo en formato pdf.
Año:2017
Volumen:77
Número:4
DOI: http://dx.doi.org/10.1140/epjc/s10052-017-4819-4
Título revista:European Physical Journal C
Título revista abreviado:Eur. Phys. J. C
ISSN:14346044
Registro:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14346044_v77_n4_p_Aaboud

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Citas:

---------- APA ----------
(2017) . Measurement of the W boson polarisation in tt¯ events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLAS. European Physical Journal C, 77(4).
http://dx.doi.org/10.1140/epjc/s10052-017-4819-4
---------- CHICAGO ----------
Aaboud, M. "Measurement of the W boson polarisation in tt¯ events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLAS" . European Physical Journal C 77, no. 4 (2017).
http://dx.doi.org/10.1140/epjc/s10052-017-4819-4
---------- MLA ----------
Aaboud, M. "Measurement of the W boson polarisation in tt¯ events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLAS" . European Physical Journal C, vol. 77, no. 4, 2017.
http://dx.doi.org/10.1140/epjc/s10052-017-4819-4
---------- VANCOUVER ----------
Aaboud, M. Measurement of the W boson polarisation in tt¯ events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLAS. Eur. Phys. J. C. 2017;77(4).
http://dx.doi.org/10.1140/epjc/s10052-017-4819-4