Combination of CDF and D0 Results on the Mass of the Top Quark

/ Authors

Tevatron Electroweak Working Group, for the Cdf Collaboration, the D0 Collaboration

/ Abstract

We summarize the top-quark mass measurements from the CDF and D0 experiments at Fermilab. We combine published Run I (1992-1996) measurements with the most recent preliminary Run II (2001-present) measurements using up to 3.6 fb-1 of data per experiment. Taking correlated uncertainties properly into account the resulting preliminary world average mass of the top quark is Mt = 173.1 +/- 0.6 (stat.) +/- 1.1 (syst.) GeV/c2, assuming Gaussian systematic uncertainties. Adding in quadrature yields a total uncertainty of 1.3 GeV/c2, corresponding to a relative precision of 0.75% on the top-quark mass.