CMS-PAS-B2G-24-009

CMS-PAS-B2G-24-009
Search for a heavy resonance produced in association with and decaying to a top quark pair in the single lepton final state in proton-proton collisions at $ \sqrt{s} = $ 13 TeV
CMS Collaboration
12 April 2025

Abstract: A search for a top-philic Z' boson in the final state with one electron or muon and jets is presented. The Z' boson is produced in association with and decays to a top quark-antiquark pair, coupling exclusively to top quarks. The analysis aims to identify a heavy Z' boson that results in Lorentz-boosted top quarks, whose hadronic decay products are merged into large-radius jets. We employ a machine learning algorithm (ParticleNet) to identify such jets. The distribution of invariant mass for the two most energetic top quark candidates is used to search for a Z' boson in the mass range of 0.5 to 3 TeV with decay widths of 4%, 10%, 20%, and 50% relative to its mass. They are found to be in agreement with the standard model background prediction. Upper limits at 95% confidence level are set on the production cross section of the Z' boson as a function of its mass, for each of the considered decay widths. These results represent the most stringent constraints to date on the existence of the Z' boson in the scenario where the Z' boson exclusively couples to top quarks. The data were recorded by the CMS experiment at the CERN LHC in proton-proton collisions at $ \sqrt{s} = $ 13 TeV and correspond to an integrated luminosity of 138 fb$ ^{-1} $.
Links: CDS record (PDF) ; CADI line (restricted) ; These preliminary results are superseded in this paper, Submitted to JHEP. The superseded preliminary plots can be found here.

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