Top quark mass measurement from dilepton events at CDF II with the matrix-element method

We describe a measurement of the top quark mass using events with two charged leptons collected by the CDF II detector from p (p) over bar collisions with root s=1.96 TeV at the Fermilab Tevatron. The likelihood in top quark mass is calculated for each event by convoluting the leading order matrix element describing q (q) over bar -> t (t) over bar -> bl nu(l)(b) over barl(')nu(l) with detector resolution functions. The presence of background events in the data sample is modeled using similar calculations involving the matrix elements for major background processes. In a data sample with integrated luminosity of 340 pb(-1), we observe 33 candidate events and measure M(top)=165.2 +/- 6.1(stat.)+/- 3.4(syst.) GeV/c(2). This measurement represents the first application of this method to events with two charged leptons and is the most precise single measurement of the top quark mass in this channel.