Measurement of the top-quark mass in all-hadronic decays in pp̄ collisions at CDF II

Abstract

We present a measurement of the top-quark mass Mtop in the all-hadronic decay channel tt̄→W+bW-b̄→q1q̄2bq3q̄4b̄. The analysis is performed using 310pb-1 of s=1.96TeV pp̄ collisions collected with the CDF II detector using a multijet trigger. The mass measurement is based on an event-by-event likelihood which depends on both the sample purity and the value of the top-quark mass, using 90 possible jet-to-parton assignments in the six-jet final state. The joint likelihood of 290 selected events yields a value of Mtop=177.1±4.9(stat)±4.7(syst)GeV/c2. © 2007 The American Physical Society.