Method for measurement of the top quark mass using the mean decay length ofbhadrons intt¯events

We present a new method for the experimental determination of the top quark mass that is based upon the mean distance of travel of $b$ hadrons in top quark events. The dominant systematic uncertainties of this method are not correlated with those of other methods, but a large number of events is required to achieve small statistical uncertainty. Large $t\overline{t}$ event samples are expected from Run II of the Fermilab Tevatron and the CERN Large Hadron Collider (LHC). We show that by the end of Run II, a single experiment at the Tevatron could achieve a top quark mass uncertainty of $\sim 5\mathrm{GeV}/c^2$ by this method alone. At the CERN LHC, this method could be comparable to all other methods, which are expected to achieve an uncertainty of $\sim 1.5\mathrm{GeV}/c^2$ per experiment. This new method would provide a useful cross-check to other methods and could be combined with them to obtain a substantially reduced overall uncertainty.