Combination of CDF and D0 results on the mass of the top quark using up   $9.7\:{\rm fb}^{-1}$ at the Tevatron
  We summarize the current top quark mass ($m_t$) 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 $p\bar{p}$ data corresponding to up to $9.7\:{\rm fb}^{-1}$ of $p\bar{p}$ 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 $m_t = 174.30 \ \pm 0.65\:\mathrm{GeV}/c^{2}$, corresponding to a relative precision of $0.37\%$ 
Tevatron Electroweak Working Group (CDF and D0 Collaborations)
hep-ex