Measurement of the top quark mass in the all-jets final state at $\sqrt{s}=13\phantom{\rule{0.166667em}{0ex}}\text{TeV}$ and combination with the lepton+jets channel

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.