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 pp̄ collisions with √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 $qq̄{→}tt̄{→}b{}{{ν}}_{{}}b̄{{}}^{{'}}{{ν}}_{{{}}^{{'}}}$ 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 Mₜₒₚ=165.2±6.1(stat.)±3.4(syst.) GeV/c². 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.