Measurement of the W-boson helicity fractions in top-quark decays at CDF
| dc.creator | Chwalek, Thorsten | |
| dc.date | 2007-05-21 | |
| dc.date.accessioned | 2026-07-07T08:02:38Z | |
| dc.date.available | 2026-07-07T08:02:38Z | |
| dc.description | We present a measurement of the fractions F_0 and F_+ of longitudinally polarized and right-handed W bosons in top-quark decays using data collected with the CDF II detector. The data set used in the analysis corresponds to an integrated luminosity of approximately 955 pb-1. We select top-antitop candidate events with one lepton, at least four jets, and missing transverse energy. Our helicity measurement uses the decay angle theta*, which is defined as the angle between the momentum of the charged lepton in the W boson rest-frame and the W momentum in the top-quark rest-frame. The cos(theta*) distribution in the data is determined by full kinematic reconstruction of the top-antotop candidates. We find F_0 = 0.59 +- 0.12 (stat) +0.07 -0.06 (syst) and F_+ = -0.03 +- 0.06 (stat) +0.04 -0.03 (syst), which is consistent with the standard model prediction. We set an upper limit on the fraction of right-handed W-bosons of F_+ < 0.1 at the 95% confidence level. | |
| dc.description | For the Proceedings of the 42nd Rencontres de Moriond 2007, Electroweak Interactions and Unified Theories | |
| dc.identifier | https://arxiv.org/abs/0705.2966 | |
| dc.identifier | http://arxiv.org/abs/0705.2966 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/129283 | |
| dc.subject | High Energy Physics - Experiment | |
| dc.title | Measurement of the W-boson helicity fractions in top-quark decays at CDF | |
| dc.type | text |