We measure the branching fraction of the top quark to longitudinally and right-handed polarized W bosons, F(0) and F(+), using approximately 200 pb(-1) of (p) over bar p collisions collected by the CDF II detector. We analyze two quantities sensitive to the W helicity: the invariant mass of the charged lepton and the bottom-quark jet in the decay t -> Wb ->l nu b (where l=e or mu), and the transverse momentum of the charged lepton. Constrained fits yield F(0)=0.74(-0.34)(+0.22), and F(+)< 0.27 at the 95% confidence level. These measurements are consistent with the standard model predictions.

Measurement of the helicity of W bosons in top-quark decays

CIOCCI, MARIA AGNESE;DONATI, SIMONE;
2006-01-01

Abstract

We measure the branching fraction of the top quark to longitudinally and right-handed polarized W bosons, F(0) and F(+), using approximately 200 pb(-1) of (p) over bar p collisions collected by the CDF II detector. We analyze two quantities sensitive to the W helicity: the invariant mass of the charged lepton and the bottom-quark jet in the decay t -> Wb ->l nu b (where l=e or mu), and the transverse momentum of the charged lepton. Constrained fits yield F(0)=0.74(-0.34)(+0.22), and F(+)< 0.27 at the 95% confidence level. These measurements are consistent with the standard model predictions.
2006
A., Abulencia; D., Acosta; J., Adelman; T., Affolder; T., Akimoto; M. G., Albrow; D., Ambrose; S., Amerio; D., Amidei; A., Anastassov; K., Anikeev; A....espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/828714
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