Precise measurement of the top-quark mass in the Lepton plus Jets topology at CDF II

We present a measurement of the mass of the top quark from proton-antiproton collisions recorded at the CDF experiment in Run II of the Fermilab Tevatron. We analyze events from the single lepton plus jets final state (t (t) over bar -> W(+)bW(-)(b) over bar -> l nu bq (q) over bar (')(b) over bar). The top-quark mass is extracted using a direct calculation of the probability density that each event corresponds to the t (t) over bar final state. The probability is a function of both the mass of the top quark and the energy scale of the calorimeter jets, which is constrained in situ by the hadronic W boson mass. Using 167 events observed in 955 pb(-1) of integrated luminosity, we achieve the single most precise measurement of the top-quark mass, 170.8 +/- 2.2(stat.) +/- 1.4(syst.) GeV/c(2).