Measurement of the W boson polarization in top quark decays with the ATLAS detector
This paper presents measurements of the polarization ofW bosons in top quark decays, derived from t{bar t} events with missing transverse momentum, one charged lepton and at least four jets, or two charged leptons and at least two jets. Data from pp collisions at a center-of-mass energy of 7 TeV were collected with the ATLAS experiment at the LHC and correspond to an integrated luminosity of 1.04 fb{sup -1}. The measured fractions of longitudinally, left- and right-handed polarization are F{sub 0} = 0.67 {+-} 0.07, F{sub L} = 0.32 {+-} 0.04 and F{sub R} = 0.01 {+-} 0.05, in agreement with the Standard Model predictions. As the polarization of the W bosons in top quark decays is sensitive to the Wtb vertex Lorentz structure and couplings, the measurements were used to set limits on anomalous contributions to the Wtb couplings.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- AC02-07CH11359
- OSTI ID:
- 1046088
- Report Number(s):
- FERMILAB-PUB-12-346-E; arXiv eprint number arXiv:1205.2484; TRN: US1203917
- Journal Information:
- Journal of High Energy Physics, Vol. 2012, Issue 6
- Country of Publication:
- United States
- Language:
- English
Similar Records
Measurement of the W boson helicity in top-antitop quark events with the CDF II experiment
Measurement of the W boson polarisation in $t\bar{t}$ events from pp collisions at $\sqrt{s} = 8$ TeV in the lepton + jets channel with ATLAS