/ Experiment-HEP arXiv:1202.5272

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

Pages: 11

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 $p\bar{p}$ collisions collected during Run II of the Fermilab Tevatron Collider. Combining measurements that simultaneously determine the fractions of $W$ bosons with longitudinal ($f_0$) and right-handed ($f_+$) helicities, we find $f_0 = 0.722 \pm 0.081\mbox{ } [ \pm \ 0.062 \hbox{ (stat.)} \pm 0.052 \hbox{ (syst.)}]$ and $f_+ = -0.033 \pm 0.046\mbox{ }[ \pm \ 0.034 \hbox{ (stat.)} \pm 0.031 \hbox{ (syst.)}]$. Combining measurements where one of the helicity fractions is fixed to the value expected in the standard model, we find $f_0 = 0.682 \pm 0.057\mbox{ }[\pm \ 0.035 \hbox{ (stat.)} \pm 0.046 \hbox{ (syst.)}]$ and $f_+ = -0.015 \pm 0.035\mbox{ }[\pm \ 0.018 \hbox{ (stat.)} \pm 0.030 \hbox{ (syst.)}]$. The results are consistent with Standard Model expectations.

Note: * Temporary entry *

Total numbers of views: 2978
Numbers of unique views: 962