Title: "Top Quark Mass Measurement in the Lepton+Jets Channel Using a Multivariate Technique at CDF"

Abstract:

We report a measurement of the top quark mass obtained from ppbar collisions at sqrt(s) = 1.96 TeV at the Fermilab Tevatron using the CDF II detector. We calculate a signal likelihood using a matrix element integration method, using ``effective propagators'' in the matrix element to take into account incorrect assumptions about some kinematic variables. We use a multivariate discriminant to distinguish signal from backgrounds. Our overall signal probability is a 2-D function of Mtop and the jet energy scale (JES), where JES is a multiplicative factor scaling all jet energies. We apply a cut to the peak value of individual event likelihoods in order to reduce the effect of badly reconstructed events. We report results based on a 955 pb^-1 sample, using events with a lepton and exactly four high-energy jets with |eta| < 2, at least one of which is tagged as coming from a b quark; 149 events pass all the selection requirements. We find Mtop = 169.8 +/- 2.3 (stat. + JES) +/- 1.4 (syst.) GeV/c^2