Top-quark mass measurement from dilepton events at CDF II

We report a measurement of the top-quark mass using events collected by the CDF II detector from pp collisions at root s=1.96 TeV at the Fermilab Tevatron. We calculate a likelihood function for the top-quark mass in events that are consistent with tt -> b center dot(-)nu(center dot)b center dot('+)nu(')(center dot) decays. The likelihood is formed as the convolution of the leading-order matrix element and detector resolution functions. The joint likelihood is the product of likelihoods for each of 33 events collected in 340 pb(-1) of integrated luminosity, yielding a top-quark mass M(t)=165.2 +/- 6.1(stat)+/- 3.4(syst) GeV/c(2). This first application of a matrix-element technique to t -> b center dot(+)nu(center dot)b center dot('-)nu(')(center dot) decays gives the most precise single measurement of M(t) in dilepton events. Combined with other CDF run II measurements using dilepton events, we measure M(t)=167.9 +/- 5.2(stat)+/- 3.7(syst) GeV/c(2).