CMS-PAS-TOP-22-008 | ||
Evidence for tWZ production in proton-proton collisions at √s= 13 TeV in multilepton final states | ||
CMS Collaboration | ||
24 May 2023 | ||
Abstract: We present the first evidence for the standard model production of a top quark in association with a W and a Z boson in multilepton final states. The Z boson is reconstructed via its decays to electron or muon pairs. The analysed data were recorded by the CMS experiment at the CERN LHC from 2016 to 2018 in proton-proton collisions at √s= 13 TeV, and correspond to an integrated luminosity of 138 fb−1. The measured cross section amounts to 0.37 ± 0.05 (stat) ± 0.10 (syst) pb, and corresponds to an observed (expected) significance of 3.5 (1.4) standard deviations. | ||
Links:
CDS record (PDF) ;
Physics Briefing ;
CADI line (restricted) ;
These preliminary results are superseded in this paper, Submitted to PLB. The superseded preliminary plots can be found here. |
Figures | |
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Figure 1:
Representative Feynman diagram for the tWZ production at NLO accuracy in QCD. |
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Figure 2:
Output node score of tWZ in SRb (left). Output node score of tWZ in SRa for events with exactly one b jet (middle), and of t¯t Z in SRa for events with more than one b jet (right). The WZ+light jets process is denoted with WZ+j in the legend. The grey uncertainty band shows the uncertainty after the fit. |
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Figure 2-a:
Output node score of tWZ in SRb (left). Output node score of tWZ in SRa for events with exactly one b jet (middle), and of t¯t Z in SRa for events with more than one b jet (right). The WZ+light jets process is denoted with WZ+j in the legend. The grey uncertainty band shows the uncertainty after the fit. |
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Figure 2-b:
Output node score of tWZ in SRb (left). Output node score of tWZ in SRa for events with exactly one b jet (middle), and of t¯t Z in SRa for events with more than one b jet (right). The WZ+light jets process is denoted with WZ+j in the legend. The grey uncertainty band shows the uncertainty after the fit. |
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Figure 2-c:
Output node score of tWZ in SRb (left). Output node score of tWZ in SRa for events with exactly one b jet (middle), and of t¯t Z in SRa for events with more than one b jet (right). The WZ+light jets process is denoted with WZ+j in the legend. The grey uncertainty band shows the uncertainty after the fit. |
Summary |
In summary, we report the first evidence for the tWZ process in final states with three or four leptons, using the data collected by the CMS experiment at the CERN LHC from 2016 to 2018, at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb−1. Despite the overwhelming contributions of irreducible backgrounds, we extract the signal with an observed statistical significance of 3.5 standard deviations, providing compelling evidence for the process. This study establishes the groundwork for future measurements with relevant implications for further investigation as more data is collected. |
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Compact Muon Solenoid LHC, CERN |
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