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

Abstract : 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^-1 of ppbar collisions collected during Run II of the Fermilab Tevatron Collider. Combining measurements that simultaneously determine the fractions of W bosons with longitudinal (f0) and right-handed (f+) helicities, we find f0 = 0.722 \pm 0.081 [\pm 0.062 (stat.) \pm 0.052 (syst.)] and f+ = -0.033 \pm 0.046 [\pm 0.034 (stat.) \pm 0.031 (syst.)]. Combining measurements where one of the helicity fractions is fixed to the value expected in the standard model, we find f0 = 0.682 \pm 0.057 [\pm 0.035 (stat.) \pm 0.046 (syst.)] and f+ = -0.015\pm0.035 [\pm 0.018 (stat.) \pm 0.030 (syst.)]. The results are consistent with standard model expectations.
docType_s : Journal articles
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Contributor : Vernay Emmanuelle <>
Submitted on : Monday, March 5, 2012 - 9:00:31 AM
Last modification on : Monday, March 5, 2012 - 9:00:31 AM

### Citation

T. Aaltonen, V. M. Abazov, B. Abbott, B. S. Acharya, M. Adams, et al.. Combination of CDF and D0 measurements of the W boson helicity in top quark decays. Physical Review D, American Physical Society, 2012, 85, pp.071106(R). <10.1103/PhysRevD.85.071106>. <in2p3-00676318>