Z and Higgs boson decays with doubly-charged scalars at one-loop: current constraints, future sensitivities, and application to lepton-triality models

Abstract

We analyse the $Z$ and Higgs boson decays $Z\to {\ell }^{+}{\ell }^{-}$ ($\ell =e,\mu ,\tau$), $H\to \gamma \gamma$ and $H\to Z\gamma$ that are induced at one-loop level in models with a doubly-charged isosinglet scalar. After discussing current constraints, we derive the parameter space that will be probed by the HL-LHC and the possible future colliders the ILC, CEPC and FCC. We then apply those constraints to lepton triality models which are based on a discrete $Z_3$ family symmetry and were recently studied in the context of charged-lepton flavour-violating processes at Belle II and the proposed ${\mu }^{+}{\mu }^{+}$ and ${\mu }^{+}{e}^{-}$ collider known as $\mu$TRISTAN. We find that the future constraints that can be imposed by $Z\to {\ell }^{+}{\ell }^{-}$ on the lepton flavour conserving couplings of the triality models reduce the viable parameter space to probe lepton flavour violating processes. The constraints from Higgs boson decays are the first on the Higgs portal sector of the triality models.

This version matches the published one. Title change and significant revision. 23 pages and 9 figures

References in corpus (44)

• FeynRules 2.0 - A complete toolbox for tree-level phenomenology
• Final Report of the Muon E821 Anomalous Magnetic Moment Measurement at BNL
• Automatized One-Loop Calculations in 4 and D dimensions
• Generating Feynman Diagrams and Amplitudes with FeynArts 3
• The anomalous magnetic moment of the muon in the Standard Model
• Precision Electroweak Measurements on the Z Resonance
• New Developments in FeynCalc 9.0
• Measurement of the fine-structure constant as a test of the Standard Model
• Leading hadronic contribution to the muon magnetic moment from lattice QCD
• Tri-Bimaximal Neutrino Mixing, A4 and the Modular Symmetry
• FeynCalc 9.3: New features and improvements
• Package-X: A Mathematica package for the analytic calculation of one-loop integrals
• A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery
• Measurement of the Positive Muon Anomalous Magnetic Moment to 0.20 ppm
• Higgs Boson Studies at Future Particle Colliders
• Package-X 2.0: A Mathematica package for the analytic calculation of one-loop integrals
• Vacuum Stability Conditions From Copositivity Criteria
• General formulae for f1 --> f2 gamma
• A comprehensive approach to new physics simulations
• A_4 flavour symmetry breaking scheme for understanding quark and neutrino mixing angles
• Search for doubly charged Higgs boson production in multi-lepton final states with the ATLAS detector using proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Observable Effects of General New Scalar Particles
• FeynCalc 10: Do multiloop integrals dream of computer codes?
• FeynHelpers: Connecting FeynCalc to FIRE and Package-X
• All electromagnetic form factors
• Constraining Flavour Symmetries At The EW Scale I: The A4 Higgs Potential
• Probing Doubly Charged Higgs Bosons at the LHC through Photon Initiated Processes
• Doubly Charged Higgs Boson Production at Hadron Colliders
• $\mu$TRISTAN
• Constraining Flavour Symmetries At The EW Scale II: The Fermion Processes
• Updated scalar sector constraints in Higgs triplet model
• Search for doubly charged Higgs boson production in multi-lepton final states using 139 fb${}^{-1}$ of proton-proton collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector
• Low- and high-energy phenomenology of a doubly charged scalar
• Lepton flavor at the electroweak scale: A complete A4 model
• Bounds on Anomalous Gauge Boson Couplings From Partial Z Widths at LEP
• Probing Lepton Flavor Triality with Higgs Boson Decay
• Doubly Charged Scalar at the High-Luminosity and High-Energy LHC
• Sensitivity of future lepton colliders to the search for charged lepton flavor violation
• Complementarity of $\mu$TRISTAN and Belle II in searches for charged-lepton flavour violation
• Sensitivity of future lepton colliders and low-energy experiments to charged lepton flavor violation from bileptons
• Lepton-flavour-violating tau decays from triality
• Decays of Standard Model like Higgs boson $h\to \gamma \gamma ,Z\gamma$ in a minimal left-right symmetric model
• The SM expected branching ratio for $h\to \gamma \gamma$ and an excess for $h\to Z\gamma$
• Neutral and Doubly-Charged Scalars at Future Lepton Colliders

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