Search for an exotic decay of the Higgs boson into a Z boson and a pseudoscalar particle in proton-proton collisions at $\sqrt{s}$ = 13 TeV

Abstract

A search for an exotic decay of the Higgs boson to a Z boson and a light pseudoscalar particle (a), decaying to a pair of leptons and a pair of photons, respectively, is presented. The search is based on proton-proton collision data at a center-of-mass energy of $\sqrt{s}$ = 13 TeV, collected with the CMS detector and corresponding to an integrated luminosity of 138 fb${}^{-1}$. The analysis probes pseudoscalar masses $m_{\mathrm{a}}$ between 1 and 30 GeV, leading to two pairs of well-isolated leptons and photons. Upper limits at 95% confidence level are set on the Higgs boson production cross section times its branching fraction to two leptons and two photons. The observed (expected) limits are in the range of 1.1-17.8 (1.7-17.9) fb within the probed $m_{\mathrm{a}}$ interval. An excess of data above the expected standard model background with a local (global) significance of 2.6 (1.3) standard deviations is observed for a mass hypothesis of $m_{\mathrm{a}}$ = 3 GeV. Limits on models involving axion-like particles, formulated as an effective field theory, are also reported.

Replaced with the published version. Added the journal reference and the DOI. All the figures and tables, including additional supplementary figures, can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/HIG-22-003 (CMS Public Pages)

References in corpus (16)

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• An Introduction to PYTHIA 8.2
• Comparative study of various algorithms for the merging of parton showers and matrix elements in hadronic collisions
• Particle-flow reconstruction and global event description with the CMS detector
• Precise determination of the mass of the Higgs boson and tests of compatibility of its couplings with the standard model predictions using proton collisions at 7 and 8 TeV
• Observation of the diphoton decay of the Higgs boson and measurement of its properties
• A portrait of the Higgs boson by the CMS experiment ten years after the discovery
• A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery
• Precision luminosity measurement in proton-proton collisions at $\sqrt{s}=$ 13 TeV in 2015 and 2016 at CMS
• Electron and photon reconstruction and identification with the CMS experiment at the CERN LHC
• Handling uncertainties in background shapes: the discrete profiling method
• Measurement of light-by-light scattering and search for axion-like particles with 2.2 nb${}^{-1}$ of Pb+Pb data with the ATLAS detector
• A search for decays of the Higgs boson to invisible particles in events with a top-antitop quark pair or a vector boson in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Search for low-mass dilepton resonances in Higgs boson decays to four-lepton final states in proton-proton collisions at $\sqrt{s}=$ 13 TeV

Cited by in corpus (3)

• Rare and exclusive few-body decays of the Higgs, Z, W bosons, and the top quark
• Leptophilic Axion-like Particles at Forward Detectors
• Rare few-body decays of the Standard Model Higgs boson