Please use this identifier to cite or link to this item:
https://hdl.handle.net/10316/108168
Title: | Measurement of the W boson polarisation in tt¯ events from pp collisions at √s = 8 TeV in the lepton + jets channel with ATLAS | Authors: | Santos, S. P. Amor dos Carvalho, J. Fiolhais, M. C. N. Galhardo, B. Veloso, F. Wolters, H. ATLAS Collaboration |
Issue Date: | 2017 | Publisher: | Springer Nature | Serial title, monograph or event: | European Physical Journal C | Volume: | 77 | Issue: | 4 | Abstract: | This paper presents a measurement of the polarisation of W bosons from t ¯t 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 theW boson rest frame is sensitive to theW boson polarisation. Two differentW 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. | URI: | https://hdl.handle.net/10316/108168 | DOI: | 10.1140/epjc/s10052-017-4819-4 | Rights: | openAccess |
Appears in Collections: | FCTUC Física - Artigos em Revistas Internacionais |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
Measurement-of-the-W-boson-polarisation-in-tt-events-from-pp-collisions-at-s--8-TeV-in-the-leptonjets-channel-with-ATLASEuropean-Physical-Journal-C.pdf | 2.54 MB | Adobe PDF | View/Open |
Page view(s)
97
checked on Oct 9, 2024
Download(s)
54
checked on Oct 9, 2024
Google ScholarTM
Check
Altmetric
Altmetric
This item is licensed under a Creative Commons License