Measurement of the top quark mass in the $t\bart\to$ dilepton channel from $\sqrts=8$ TeV ATLAS data

摘要: The top quark mass is measured in the tt¯→ dilepton channel (lepton =e,μ) using ATLAS data recorded in the year 2012 at the LHC. The data were taken at a proton--proton centre-of-mass energy of s√= 8 TeV and correspond to an integrated luminosity of about 20.2 fb−1. Exploiting the template method, and using the distribution of invariant masses of lepton--b-jet pairs, the top quark mass is measured to be mtop= 172.99 ± 0.41 (stat) ± 0.74 (syst) GeV, with a total uncertainty of 0.84 GeV. Finally, a combination with previous ATLAS mtop measurements from s√=7 TeV data in the tt¯→ dilepton and tt¯→ lepton+jets channels results in mtop= 172.84 ± 0.34 (stat) ± 0.61 (syst) GeV, with a total uncertainty of 0.70 GeV.