Measurement of W-boson polarization in top-quark decay using the full CDF Run II data set

We measure the polarization of W bosons from top-quark (t) decays into final states with a charged lepton and jets, tt̄→W+bW -b̄→ℓνbqq̄′b̄, using the full Run II data set collected by the CDF II detector, corresponding to an integrated luminosity of 8.7 fb-1. A model-independent method simultaneousl...

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Bibliographic Details
Main Authors: Aaltonen, T, Amerio, S, Amidei, D, Anastassov, A, Annovi, A, Antos, J, Apollinari, G, Appel, J, Arisawa, T, Artikov, A, Asaadi, J, Ashmanskas, W, Auerbach, B, Aurisano, A, Azfar, F, Badgett, W, Bae, T, Barbaro-Galtieri, A, Barnes, V, Barnett, B, Barria, P, Bartos, P, Bauce, M, Bedeschi, F, Behari, S
Format: Journal article
Language:English
Published: 2013
Description
Summary:We measure the polarization of W bosons from top-quark (t) decays into final states with a charged lepton and jets, tt̄→W+bW -b̄→ℓνbqq̄′b̄, using the full Run II data set collected by the CDF II detector, corresponding to an integrated luminosity of 8.7 fb-1. A model-independent method simultaneously determines the fraction of longitudinal (f0) and right-handed (f+) W bosons to yield f0=0.726±0. 066(stat)±0.067(syst) and f+=-0.045±0.044(stat) ±0.058(syst) with a correlation coefficient of -0.69. Additional results are presented under various standard model assumptions. No significant discrepancies with the standard model are observed. © 2013 American Physical Society.