Measurement of the top quark mass with the collider detector at Fermilab

Abstract

This report describes a measurement of the top quark mass in $p\overline{p}$ collisions at a center of mass energy of 1.8 TeV. The data sample was collected with the CDF detector during the 1992--1995 collider run at the Fermilab Tevatron, and corresponds to an integrated luminosity of 106 ${\mathrm{pb}}^{\mathrm{\ensuremath{-}}1}$. Candidate $t\overline{t}$ events in the ``$\mathrm{l}\mathrm{e}\mathrm{p}\mathrm{t}\mathrm{o}\mathrm{n}+\mathrm{j}\mathrm{e}\mathrm{t}\mathrm{s}$'' decay channel provide our most precise measurement of the top quark mass. For each event a top quark mass is determined by using energy and momentum constraints on the production of the $t\overline{t}$ pair and its subsequent decay. A likelihood fit to the distribution of reconstructed masses in the data sample gives a top quark mass in the $\mathrm{l}\mathrm{e}\mathrm{p}\mathrm{t}\mathrm{o}\mathrm{n}+\mathrm{j}\mathrm{e}\mathrm{t}\mathrm{s}$ channel of $176.1\ifmmode\pm\else\textpm\fi{}5.1(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}5.3(\mathrm{syst})\mathrm{}\mathrm{GeV}{/c}^{2}.$ Combining this result with measurements from the ``all-hadronic'' and ``dilepton'' decay topologies yields a top quark mass of $176.1\ifmmode\pm\else\textpm\fi{}6.6\mathrm{GeV}{/c}^{2}.$