Combination of CDF and D0 measurements of the W boson helicity in top quark decays

We report the combination of recent measurements of the helicity of the W boson from top quark decay by the CDF and D0 collaborations, based on data samples corresponding to integrated luminosities of 2.7–5.4  fb[superscript -1] of pp̅ collisions collected during Run II of the Fermilab Tevatron coll...

Full description

Bibliographic Details
Main Authors: Gomez-Ceballos, Guillelmo, Goncharov, Maxim, Paus, Christoph M. E.
Other Authors: Massachusetts Institute of Technology. Laboratory for Nuclear Science
Format: Article
Language:en_US
Published: American Physical Society 2012
Online Access:http://hdl.handle.net/1721.1/71676
https://orcid.org/0000-0002-6047-4211
Description
Summary:We report the combination of recent measurements of the helicity of the W boson from top quark decay by the CDF and D0 collaborations, based on data samples corresponding to integrated luminosities of 2.7–5.4  fb[superscript -1] of pp̅ collisions collected during Run II of the Fermilab Tevatron collider. Combining measurements that simultaneously determine the fractions of W bosons with longitudinal (f[subscript 0]) and right-handed (f[subscript +]) helicities, we find f[subscript 0]=0.722±0.081[±0.062(stat)±0.052(syst)] and f[subscript +]=-0.033±0.046[±0.034(stat)±0.031(syst)]. Combining measurements where one of the helicity fractions is fixed to the value expected in the standard model, we find f[subscript 0]=0.682±0.057[±0.035(stat)±0.046(syst)] for fixed f[subscript +] and f[subscript +]=-0.015±0.035[±0.018(stat)±0.030(syst)] for fixed f[subscript 0]. The results are consistent with standard model expectations.