Precise Measurement of the Top Quark Mass from Lepton+Jets Events

We report a measurement of the mass of the top quarkin lepton+jets final states of ppbar->ttbar data corresponding to 2.6 fb-1 of integrated luminositycollected by the D0 experimentat the Fermilab TevatronCollider. Using a matrix element method, we combine an insitu jet energy calibration with our standard jet energy scale derived in studies of {\gamma}+jet and dijet events and employ a novel flavor-dependent jet response correction to measure a top-quarkmass of mt = 176.01 +/- 1.64 GeV. Combining this result with our previous result obtained on an independent data set, we measure a top-quarkmass of mt = 174.94 +/- 1.49 GeV for a total integrated luminosityof 3.6 fb-1 .