Measurement of the top quark mass in the all- jets final state at root s=13 TeV and combination with the lepton plus jets channel

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A top quark mass measurement is performed using (35.9\phantom{\rule{0.166667em}{0ex}}{\text{fb}}^{-1}) of LHC proton–proton collision data collected with the CMS detector at (\sqrt{s}=13\phantom{\rule{0.166667em}{0ex}}\text{TeV}). The measurement uses the (t\overline{t}) all-jets final state. A kinematic fit is performed to reconstruct the decay of the (t\overline{t}) system and suppress the multijet background. Using the ideogram method, the top quark mass ( ({m}{t}) ) is determined, simultaneously constraining an additional jet energy scale factor ( (\text{JSF}) ). The resulting value of ({m}{t}=172.34±0.20\phantom{\rule{0.166667em}{0ex}}\text{(stat+JSF)}±0.70\phantom{\rule{0.166667em}{0ex}}\text{(syst)}\phantom{\rule{0.166667em}{0ex}}\text{GeV}) is in good agreement with previous measurements. In addition, a combined measurement that uses the (t\overline{t}) lepton+jets and all-jets final states is presented, using the same mass extraction method, and provides an ({m}{t}) measurement of (172.26±0.07\phantom{\rule{0.166667em}{0ex}}\text{(stat+JSF)}±0.61\phantom{\rule{0.166667em}{0ex}}\text{(syst)}\phantom{\rule{0.166667em}{0ex}}\text{GeV}). This is the first combined ({m}{t}) extraction from the lepton+jets and all-jets channels through a single likelihood function.

Physics, Particles & Fields, Physics
Sirunyan, A. M., Tumasyan, A., Adam, W., Ambrogi, F., Asilar, E., Bergauer, T., Brandstetter, J., Dragicevic, M., Erö, J., Del Valle, A. E., Flechl, M., Frühwirth, R., Ghete, V. M., Hrubec, J., Jeitler, M., Krammer, N., Krätschmer, I., Liko, D., … Woods, N. (2019). Measurement of the top quark mass in the all-jets final state at $\sqrt{s}=13\,\text {TeV} $ $\sqrt{s}$=13TeV and combination with the lepton+jets channel. In The European Physical Journal C (Vol. 79, Issue 4). Springer Science and Business Media LLC.