Search for Higgs Boson Decays into a Z Boson and a Light Hadronically Decaying Resonance Using 13 TeV pp Collision Data from the ATLAS Detector

Summary, in English

A search for Higgs boson decays into a Z boson and a light resonance in two-lepton plus jet events is performed, using a pp collision dataset with an integrated luminosity of 139 fb-1 collected at s=13 TeV by the ATLAS experiment at the CERN LHC. The resonance considered is a light boson with a mass below 4 GeV from a possible extended scalar sector or a charmonium state. Multivariate discriminants are used for the event selection and for evaluating the mass of the light resonance. No excess of events above the expected background is found. Observed (expected) 95% confidence-level upper limits are set on the Higgs boson production cross section times branching fraction to a Z boson and the signal resonance, with values in the range 17-340 pb (16-5+6-320-90+130 pb) for the different light spin-0 boson mass and branching fraction hypotheses, and with values of 110 and 100 pb (100-30+40 and 100-30+40 pb) for the ηc and J/ψ hypotheses, respectively. © 2020 CERN. © 2020 CERN, for the ATLAS Collaboration. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/" Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.

• Author: G Aad; Torsten Åkesson; Simona Bocchetta; Eric Edward Corrigan; Caterina Doglioni; Jannik Geisen; Kristian Gregersen; Eva Brottmann Hansen; Vincent Hedberg; Göran Jarlskog; Edgar Kellermann; Balazs Konya; Else Lytken; Katja Mankinen; Caterina Marcon; Ulf Mjörnmark; Geoffrey André Adrien Mullier; Ruth Pöttgen; Trine Poulsen; Eleni Skorda; Oxana Smirnova; L Zwalinski
• Department/s: Particle and nuclear physics; eSSENCE: The e-Science Collaboration
• Publishing year: 2020
• Language: English
• Publication/Series: Physical Review Letters
• Volume: 125
• Issue: 22
• Links: http://dx.doi.org/10.1103/PhysRevLett.125.221802
• Document type: Journal article
• Publisher: American Physical Society
• Topic: Subatomic Physics
• Keywords: Germanium compounds; Resonance; ATLAS detectors; ATLAS experiment; Branching fractions; Confidence levels; Different lights; Higgs Boson decay; Integrated luminosity; Production cross section; Bosons; article; boson; lepton; luminance
• Status: Published
• ISBN/ISSN/Other: ISSN: 1079-7114