Summary of Top Mass Results - March 2007

Summary of top mass measurements from the CDF and D0 experiments at Fermilab by March 2007. We combine published results from Run-I (1992-1996) with the most recent preliminary and published Run-II (2001-present) measurements using up to 1fb-1 of data. Taking correlated uncertainties properly into account the resulting preliminary world average mass of the top quark is

Mtop = 170.9 ± 1.1 (stat) ± 1.5 (syst) GeV/c2

which corresponds to a total uncertainty of 1.8 GeV/c2. The top quark mass is now known with a precision of 1.1%.

More information can be found at hep-ex/0703034, CDF Note 8735, D0 Note 5378.

References about the individual analyses contributing to this combination can be found at

CDF public page
D0 public page

Click on image for .eps format.

Most precise results from each channel from the D0 and CDF experiments.
Combination fits for the top quark mass in the all-jets, lepton+jets, dilepton channels separately. Same methodology as the one used for the Tevatron combination but but fit for the three physical pbservables, Mtop in all-jets, lepton+jets, dilepton. The chi square refers to the consistency between any two channels including all correlations. The determinations of Mtop are consistent with one another.
Weights of each analysis in the Tevatron combination.
Most recent CDF results using different techniques and channels compared to the Tevatron average. Measurements in blue were included in the CDF combination of March, 2007. (see March 2007 CDF combination page)
Measurements included in the CDF combination of March, 2007. (see March 2007 CDF combination page)