1999/09/23 by A. A. Affolder, CDF Collaboration, T. Affolder +99 · 1 citation
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1103/physrevlett.84.216
published as Phys.Rev.Lett.84:216-221,2000 · Submitted to PRL. 8 pages, 2 figures
arxiv created 1999/09/23 · openalex publication_date 2000/01/10 · arxiv updated 2010/05/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04
We use the transverse momentum spectrum of leptons in the decay chain t\ensuremath→bW with W\ensuremath→l\ensuremathν to measure the helicity of the W bosons in the top quark rest frame. Our measurement uses a tt sample isolated in 106\ifmmode±\else\textpm\fi4pb^\ensuremath-1 of data collected in pp collisions at √(s)\phantom\rule0ex0ex=\phantom\rule0ex0ex1.8\phantom\rule0ex0exTeV with the CDF detector at the Fermilab Tevatron. Assuming a standard V\ensuremath-A weak decay, we find that the fraction of W's with zero helicity in the top rest frame is F0\phantom\rule0ex0ex=\phantom\rule0ex0ex0.91\ifmmode±\else\textpm\fi0.37(stat)\ifmmode±\else\textpm\fi0.13(syst), consistent with the standard model prediction of F0\phantom\rule0ex0ex=\phantom\rule0ex0ex0.70 for a top mass of 175GeV/c2.