Measurement of the top quark mass in the dilepton channel using m_T2} at CDF

Abstract

We present measurements of the top quark mass using m_T2, a variable related to the transverse mass in events with two missing particles. We use the template method applied to tt̅ dilepton events produced in pp̅ collisions at Fermilab’s Tevatron Collider and collected by the CDF detector. From a data sample corresponding to an integrated luminosity of 3.4  fb^-1, we select 236 tt̅ candidate events. Using the m_T2 distribution, we measure the top quark mass to be Mtop=168.0-4.0+4.8(stat)±2.9(syst)  GeV/c². By combining m_T2 with the reconstructed top quark mass distributions based on a neutrino weighting method, we measure M_top=169.3±2.7(stat)±3.2(syst)  GeV/c². This is the first application of the m_T2 variable in a mass measurement at a hadron collider