We summarize the current top quark mass (mt) measurements from the CDF and D0 experiments at Fermilab. We combine published results from Run I (1992--1996) with the most precise published and preliminary Run II (2001--2011) measurements based on ppˉ data corresponding to up to 9.7fb−1
Nearby in the stack
of
ppˉ
collisions. Taking correlations of uncertainties into account, and combining the statistical and systematic contributions in quadrature, the preliminary Tevatron average mass value for the top quark is