Measurement of the top quark mass using dilepton events

Abstract

The D0 Collaboration has performed a measurement of the top quark mass m_t based on six candidate events for the process tt̅→bW⁺b̅W^-, where the W bosons decay to eν or μν. This sample was collected during an exposure of the D0 detector to an integrated luminosity of 125 pb^-1 of √s=1.8 TeV pp̅ collisions. We obtain m_t=168.4±12.3(stat)±3.6(syst) GeV/c², consistent with the measurement obtained using single-lepton events. Combination of the single-lepton and dilepton results yields m_t=172.0±7.5 GeV/c².