Abstract
We present a measurement of W boson polarization in top-quark decays in tt¯ events with decays to dilepton final states using 5.1fb−1 of integrated luminosity in pp¯ collisions collected by the CDF II detector at the Tevatron. A simultaneous measurement of the fractions of longitudinal (f0) and right-handed (f+) W bosons yields the results f0=0.71+0.18−0.17(stat)±0.06(syst) and f+=−0.07±0.09(stat)±0.03(syst). Combining this measurement with our previous result based on single lepton final states, we obtain f0=0.84±0.09(stat)±0.05(syst) and f+=−0.16±0.05(stat)±0.04(syst). The results are consistent with standard model expectation.
CDF Collaboration