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arXiv · hep-ex/0609045

Measurement of the W boson helicity in top quark decay at D0

D0 Collaboration·V. M. Abazov
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Abstract

We present a measurement of the fraction f_+ of right-handed W bosons produced in top quark decays, based on a candidate sample of ttbar events in the l+jets and dilepton decay channels corresponding to an integrated luminosity of 370 pb^-1 collected by the DO detector at the Fermilab Tevatron ppbar Collider at sqrt{s}=1.96 TeV. We reconstruct the decay angle theta^* for each lepton. By comparing the \cosθ^* distribution from the data with those for the expected background and signal for various values of f_+, we find $f_+=0.056 +- 0.080 (stat) +- 0.057 (syst)}. (f_+ < 0.23 at 95% C.L.), consistent with the standard model prediction of f_+=3.6 x10^-4.

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D0 Collaboration, V. M. Abazov. 2006-09-25. Measurement of the W boson helicity in top quark decay at D0. https://doi.org/10.1103/physrevd.75.031102

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