Measurement of the top quark mass at CDF using the "neutrino phi weighting" template method on a lepton plus isolated track sample

Abstract

We present a measurement of the top quark mass with t(t)over bar dilepton events produced in p(p)over bar collisions at the Fermilab Tevatron (root s=1.96 TeV) and collected by the CDF II detector. A sample of 328 events with a charged electron or muon and an isolated track, corresponding to an integrated luminosity of 2.9 fb(-1), are selected as t(t)over bar candidates. To account for the unconstrained event kinematics, we scan over the phase space of the azimuthal angles (phi(nu 1),phi(nu 2)) of neutrinos and reconstruct the top quark mass for each phi(nu 1), phi(nu 2) pair by minimizing a chi(2) function in the t(t)over bar dilepton hypothesis. We assign chi(2)-dependent weights to the solutions in order to build a preferred mass for each event. Preferred mass distributions (templates) are built from simulated t(t)over bar and background events, and parametrized in order to provide continuous probability density functions. A likelihood fit to the mass distribution in data as a weighted sum of signal and background probability density functions gives a top quark mass of 165.5(-3.3)(+3.4)(stat)+/- 3.1(syst) GeV/c(2).