Precise Measurement of the Top Quark Mass in the Dilepton Channel at D0

Abstract

We measure the top quark mass (${m}_{t}$) in $p\overline{p}$ collisions at a center of mass energy $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ using dilepton $t\overline{t}\ensuremath{\rightarrow}{W}^{+}b{W}^{\ensuremath{-}}\overline{b}\ensuremath{\rightarrow}{\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}b{\ensuremath{\ell}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\ell}}\overline{b}$ events, where $\ensuremath{\ell}$ denotes an electron, a muon, or a tau that decays leptonically. The data correspond to an integrated luminosity of $5.4\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected with the D0 detector at the Fermilab Tevatron Collider. We obtain ${m}_{t}=174.0\ifmmode\pm\else\textpm\fi{}1.8(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}2.4(\mathrm{syst})\text{ }\text{ }\mathrm{GeV}$, which is in agreement with the current world average ${m}_{t}=173.3\ifmmode\pm\else\textpm\fi{}1.1\text{ }\text{ }\mathrm{GeV}$. This is currently the most precise measurement of ${m}_{t}$ in the dilepton channel.