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arXiv · hep-ex/9909042

Measurement of the Helicity of W Bosons in Top Quark Decays

CDF Collaboration·T. Affolder
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Abstract

We use the transverse momentum spectrum of leptons in the decay chain t-->bW with W-->l nu to measure the helicity of the W bosons in the top quark rest frame. Our measurement uses a ttbar sample isolated in 106 +/- 4 inverse picobarns of data collected in ppbar collisions at sqrt(s)=1.8 TeV with the CDF detector at the Fermilab Tevatron. Assuming a standard V--A weak decay, we find that the fraction of W's with zero helicity in the top rest frame is F_0 = 0.91 +/- 0.37 (stat) +/- 0.13 (syst), consistent with the standard model prediction of F_0=0.70 for a top mass of 175 GeV/c**2.

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CDF Collaboration, T. Affolder. 1999-09-23. Measurement of the Helicity of W Bosons in Top Quark Decays. https://doi.org/10.1103/physrevlett.84.216

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