%0 Journal Article %T Measurement of W-Boson Polarization in Top-Quark Decay in p(p)over-bar Collisions at root s=1.96 TeV %A CDF Collaboration (Aaltonen, T. et al %A Cabrera, S. %J Physical Review Letters %D 2010 %V 105 %N 4 %I Amer Physical Soc %@ 0031-9007 %G English %F CDFCollaborationAaltonen+Cabrera2010 %O ISI:000280234400009 %O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=279), last updated on Mon, 21 Feb 2011 12:22:10 +0000 %X We report measurements of the polarization of W bosons from top-quark decays using 2.7 fb(-1) of p (p) over bar collisions collected by the CDF II detector. Assuming a top-quark mass of 175 GeV/c(2), three measurements are performed. A simultaneous measurement of the fraction of longitudinal (f(0)) and right-handed (f(0)) W bosons yields the model- independent results f(0) =0. 88 +/- 0.11(stat) +/- 0.06(syst) and f(+) = 0.15 +/- 0.07(stat) +/- 0.06(syst) with a correlation coefficient of -0.59. A measurement of f(0) [f(+)] constraining f(+) [f(0)] to its standard model value of 0.0 [0.7] yields f(0) 0.70 + 0.07(stat) +/- 0.04(syst) [f(+) – 0.01 +/- 0.02(stat) +/- 0.05(syst)]. All these results are consistent with standard model expectations. We achieve the single most precise measurements of f(0) for both the model- independent and modeldependent determinations. %R 10.1103/PhysRevLett.105.042002 %U http://arXiv.org/abs/1003.0224 %U https://doi.org/10.1103/PhysRevLett.105.042002 %P 042002-8pp