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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Abstract
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.