Top quark mass measurement using the template method at CDF

We present a measurement of the top quark mass in the $\mathrm{\text{lepton}}+\mathrm{\text{jets}}$ and dilepton channels of $t\overline{t}$ decays using the data sample corresponding to an integrated luminosity of $5.6{\mathrm{fb}}^{-1}$ of $p\overline{p}$ collisions at Tevatron with $\sqrt{s}=1.96\mathrm{TeV}$, collected with the CDF II detector. We construct templates of two reconstructed top quark masses from different jets-to-quarks combinations and the invariant mass of two jets from the $W$ decays in the $\mathrm{\text{lepton}}+\mathrm{\text{jets}}$ channel, and a reconstructed top quark mass and $m_{T2}$, a variable related to the transverse mass in events with two missing particles, in the dilepton channel. The simultaneous fit of the templates from signal and background events in the $\mathrm{\text{lepton}}+\mathrm{\text{jets}}$ and dilepton channels to the data yields a measured top quark mass of ${\mathrm{M}}_{\mathrm{top}}=172.1\pm 1.1(\mathrm{stat})\pm 0.9(\mathrm{syst})\mathrm{GeV}/c^2$.

Figure 1

Distributions of the three variables used to measure ${\mathrm{M}}_{\mathrm{top}}$ in the $\mathrm{\text{lepton}}+\mathrm{\text{jets}}$ channel, showing 1-tag and 2-tag samples separately. The data are overlaid with the predictions from the KDE probability distributions using ${\mathrm{M}}_{\mathrm{top}}=172.0\mathrm{GeV}/c^2$ and the full background model.

Figure 2

Distributions of the two variables used to measure ${\mathrm{M}}_{\mathrm{top}}$ in the dilepton channel, showing nontagged and tagged samples separately. The data are overlaid with the predictions from the KDE probability distributions using ${\mathrm{M}}_{\mathrm{top}}=170.0\mathrm{GeV}/c^2$ and the full background model.