Measurement of the top-quark mass in the lepton+jets channel using a matrix element technique with the CDF II detector

Résumé fourni par la source

A measurement of the top-quark mass is presented using Tevatron data from proton-antiproton collisions at center-of-mass energy $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ collected with the CDF II detector. Events are selected from a sample of candidates for production of $t\overline{t}$ pairs that decay into the $\mathrm{\text{lepton}}+\mathrm{\text{jets}}$ channel. The top-quark mass is measured with an unbinned maximum likelihood method where the event probability density functions are calculated using signal and background matrix elements, as well as a set of parametrized jet-to-parton transfer functions. The likelihood function is maximized with respect to the top-quark mass, the signal fraction in the sample, and a correction to the jet energy scale (JES) calibration of the calorimeter jets. The simultaneous measurement of the JES correction (${\ensuremath{\Delta}}_{\mathrm{JES}}$) amounts to an additional in situ jet energy calibration based on the known mass of the hadronically decaying $W$ boson. Using the data sample of 578 $\mathrm{\text{lepton}}+\mathrm{\text{jets}}$ candidate events, corresponding to $3.2\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of integrated luminosity, the top-quark mass is measured to be ${m}_{t}=172.4\ifmmode\pm\else\textpm\fi{}1.4(\mathrm{stat}+{\ensuremath{\Delta}}_{\mathrm{JES}})\ifmmode\pm\else\textpm\fi{}1.3(\mathrm{syst})\text{ }\text{ }\mathrm{GeV}/{c}^{2}$.

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