Measurement of the top quark mass in the channel using the lepton transverse momentum

This Letter reports a measurement of the top quark mass, Mtop, in data from pp collisions at √s=1.96 TeV corresponding to 2.7 fb −1 of integrated luminosity at the Fermilab Tevatron using the CDF II detector. Events with the lepton+jets topology are selected. An unbinned likelihood is constructed based on the dependence of the lepton transverse momentum, PT, on M top . A maximum likelihood fit to the data yields a measured mass M top =176.9±stat 8.0 ±syst 2.7 GeV/c 2 . In this measurement, the contribution by the jet energy scale uncertainty to the systematic error is negligible. The result provides an important consistency test for other M top measurements where explicit use of the jet energy is made for deriving the top quark mass.