Measurement of the top-quark mass in the fully hadronic decay channel from ATLAS data at root s=7 Tev
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CitationAdd, G., Abbott, B., Abdallah, J., Khalek, S. A., Abdinov, O., Aben, R. ... ATLAS Collaboration. (2015). Measurement of the top-quark mass in the fully hadronic decay channel from ATLAS data at root s=7 Tev. European Physical Journal C, 75(4), 1-26. http://dx.doi.org/10.1140/epjc/s10052-015-3373-1
The mass of the top quark is measured in a data set corresponding to 4.6 fb(-1) of proton-proton collisions with centre-of-mass energy root s = 7 TeV collected by the ATLAS detector at the LHC. Events consistent with hadronic decays of top-antitop quark pairs with at least six jets in the final state are selected. The substantial background from multijet production is modelled with data-driven methods that utilise the number of identified b-quark jets and the transverse momentum of the sixth leading jet, which have minimal correlation. The top-quark mass is obtained from template fits to the ratio of three-jet to dijet mass. The three-jet mass is calculated from the three jets produced in a top-quark decay. Using these three jets the dijet mass is obtained from the two jets produced in the W boson decay. The top-quark mass obtained from this fit is thus less sensitive to the uncertainty in the energy measurement of the jets. A binned likelihood fit yields a top-quark mass of m(t) = 175.1 +/- 1.4 (stat.) +/- 1.2 (syst.) GeV.