Abstract
The W boson helicity fractions from top quark decays in tt‾ events are measured using data from proton–proton collisions at a centre-of-mass energy of 8TeV. The data were collected in 2012 with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.8fb−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 F0=0.681±0.012(stat)±0.023(syst), FL=0.323±0.008(stat)±0.014(syst), and FR=−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.
Original language | English |
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Pages (from-to) | 512-534 |
Number of pages | 23 |
Journal | Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics |
Volume | 762 |
DOIs | |
Publication status | Published - 2016 Nov 10 |
Bibliographical note
Publisher Copyright:© 2016 The Author
Keywords
- Anomalous couplings
- CMS
- Helicity
- Physics
- Top
ASJC Scopus subject areas
- Nuclear and High Energy Physics