Measurement of the Top Quark Mass using Quantities with Minimal Dependence on the Jet Energy Scale

TL;DR

This paper reports three measurements of the top quark mass using variables minimally affected by jet energy scale uncertainties, achieving results with reduced systematic errors at CDF with 1.9 fb-1 of data.

Contribution

The study introduces three novel methods for measuring the top quark mass that rely on variables with minimal jet energy scale dependence, improving measurement precision.

Findings

Top mass measured as 176.7 GeV/c^2 with L2d variable

Top mass measured as 173.5 GeV/c^2 with LepPt variable

Combined measurement yields 175.3 GeV/c^2 with reduced uncertainties

Abstract

We present three measurements of the top quark mass in the lepton plus jets channel with 1.9 fb-1 of data using quantities with minimal dependence on the jet energy scale in the lepton plus jets channel at CDF. One measurement uses the mean transverse decay length of b-tagged jets (L2d) to determine the top mass, another uses the transverse momentum of the lepton (LepPt) to determine the top mass, and a third measurement uses both variables simultaneously. Using the L2d variable we measure a top mass of 176.7 (+10.0) (-8.9) (stat) +/- 3.4 (syst) GeV/c^2, using the LepPt variable we measure a top mass of 173.5 (+8.9) (-9.1) (stat) +/- 4.2 (syst) GeV/c^2, and doing the combined measurement using both variables we arrive at a top mass result of 175.3 +/- 6.2 (stat) +/- 3.0 (syst) GeV/c^2. Since some of the systematic uncertainties are statistically limited, these results are expected to improve significantly if more data is added at the Tevatron in the future, or if the measurement is done at the LHC.