We present a measurement of the total decay width of the top quark using events with top-antitop quark pair candidates reconstructed in the final state with one charged lepton and four or more hadronic jets. We use the full Tevatron run II data set of $\sqrt{s}=1.96\mathrm{TeV}$ proton-antiproton collisions recorded by the CDF II detector. The top quark mass and the mass of the hadronically decaying $W$ boson are reconstructed for each event and compared with distributions derived from simulated signal and background samples to extract the top quark width (${\Gamma }_{\mathrm{top}}$) and the energy scale of the calorimeter jets with in situ calibration. For a top quark mass $M_{\mathrm{top}}=172.5\mathrm{GeV}/c^2$, we find $1.10<{\Gamma }_{\mathrm{top}}<4.05\mathrm{GeV}$ at 68% confidence level, which is in agreement with the standard model expectation of 1.3 GeV and is the most precise direct measurement of the top quark width to date.

• Received 19 August 2013

DOI:https://doi.org/10.1103/PhysRevLett.111.202001