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# Measurement of the W boson helicity fractions in the decays of top quark pairs to lepton $+$ jets final states produced in pp collisions at $sqrt s=$ 8TeV

The CMS Collaboration (2016) Measurement of the W boson helicity fractions in the decays of top quark pairs to lepton $+$ jets final states produced in pp collisions at $sqrt s=$ 8TeV. Physics Letters B, B762, 512-534.

Record type: Article

## Abstract

The W boson helicity fractions from top quark decays in View the MathML sourcett‾ events are measured using data from proton–proton collisions at a centre-of-mass energy of View the MathML source8TeV. The data were collected in 2012 with the CMS detector at the LHC, corresponding to an integrated luminosity of View the MathML source19.8fb−1. Events are reconstructed with either one muon or one electron, along with four jets in the final state, with two of the jets being identified as originating from b quarks. The measured helicity fractions from both channels are combined, yielding View the MathML sourceF0=0.681±0.012(stat)±0.023(syst), View the MathML sourceFL=0.323±0.008(stat)±0.014(syst), and View the MathML sourceFR=−0.004±0.005(stat)±0.014(syst) for the longitudinal, left-, and right-handed components of the helicity, respectively. These measurements of the W boson helicity fractions are the most accurate to date and they agree with the predictions from the standard model.

Text
hS0370269316305780-main - Version of Record

Accepted/In Press date: 4 October 2016
e-pub ahead of print date: 11 October 2016
Organisations: Physics & Astronomy

## Identifiers

Local EPrints ID: 408214
URI: http://eprints.soton.ac.uk/id/eprint/408214
ISSN: 0370-2693
PURE UUID: beb78d87-9d69-4c77-8b6d-9e6677e4c52d
ORCID for Alexander Belyaev: orcid.org/0000-0002-1733-4408

## Catalogue record

Date deposited: 17 May 2017 04:01

## Contributors

Author: Vardan Khachatryan
Corporate Author: The CMS Collaboration