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Measurement of the Top Quark Mass using Template Methods on Dilepton Events in Proton-Antiproton Collisions at sqrt(s)=1.96 TeV

A. Abulencia

TL;DR

This work targets a precise measurement of the top quark mass in the dilepton ttbar channel using template methods. Three independent mass reconstruction techniques (NWA, KIN, PHI) are applied to data collected with the CDF II detector, each relying on different kinematic constraints and combined via a likelihood framework with background templates. Systematic and statistical uncertainties are evaluated with pseudo-experiments, and the three measurements are BLUE-weighted to yield a single top mass. The combined result, m_t = 170.1 ± 6.0 (stat) ± 4.1 (syst) GeV/c^2, agrees with other CDF measurements and supports the Standard Model without indicating new physics in the dilepton channel.

Abstract

We describe a measurement of the top quark mass from events produced in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV, using the Collider Detector at Fermilab. We identify top-antitop candidates where both W bosons from the top quarks decay into leptons (electron, muon, or tau plus neutrino) from a data sample of 360 inverse picobarns. The top quark mass is reconstructed in each event separately by three different methods, which draw upon simulated distributions of the neutrino pseudorapidity, top-antitop longitudinal momentum, or neutrino azimuthal angle in order to extract probability distributions for the top quark mass. For each method, representative mass distributions, or templates, are constructed from simulated samples of signal and background events, and parameterized to form continuous probability density functions. A likelihood fit incorporating these parameterized templates is then performed on the data sample masses in order to derive a final top quark mass. Combining the three template methods, taking into account correlations in their statistical and systematic uncertainties, results in a top quark mass measurement of 170.1 +/- 6.0 (stat) +/- 4.1 (syst) GeV/c^2.

Measurement of the Top Quark Mass using Template Methods on Dilepton Events in Proton-Antiproton Collisions at sqrt(s)=1.96 TeV

TL;DR

This work targets a precise measurement of the top quark mass in the dilepton ttbar channel using template methods. Three independent mass reconstruction techniques (NWA, KIN, PHI) are applied to data collected with the CDF II detector, each relying on different kinematic constraints and combined via a likelihood framework with background templates. Systematic and statistical uncertainties are evaluated with pseudo-experiments, and the three measurements are BLUE-weighted to yield a single top mass. The combined result, m_t = 170.1 ± 6.0 (stat) ± 4.1 (syst) GeV/c^2, agrees with other CDF measurements and supports the Standard Model without indicating new physics in the dilepton channel.

Abstract

We describe a measurement of the top quark mass from events produced in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV, using the Collider Detector at Fermilab. We identify top-antitop candidates where both W bosons from the top quarks decay into leptons (electron, muon, or tau plus neutrino) from a data sample of 360 inverse picobarns. The top quark mass is reconstructed in each event separately by three different methods, which draw upon simulated distributions of the neutrino pseudorapidity, top-antitop longitudinal momentum, or neutrino azimuthal angle in order to extract probability distributions for the top quark mass. For each method, representative mass distributions, or templates, are constructed from simulated samples of signal and background events, and parameterized to form continuous probability density functions. A likelihood fit incorporating these parameterized templates is then performed on the data sample masses in order to derive a final top quark mass. Combining the three template methods, taking into account correlations in their statistical and systematic uncertainties, results in a top quark mass measurement of 170.1 +/- 6.0 (stat) +/- 4.1 (syst) GeV/c^2.

Paper Structure

This paper contains 2 sections, 1 figure.

Table of Contents

  1. Introduction
  2. Detector and Event Selection

Figures (1)

  • Figure 1: Elevation view of the CDF II detector, showing the inner silicon microstrip detector, Central Outer Tracker drift chamber, electromagnetic and hadronic calorimeters, and muon drift chambers and scintillation counters.