Gabriela Lichtenstein , Michael A. Schmidt , German Valencia , Raymond R. Volkas
{"title":"Z and Higgs boson decays with doubly-charged scalars at one-loop: Current constraints, future sensitivities, and application to lepton-triality models","authors":"Gabriela Lichtenstein , Michael A. Schmidt , German Valencia , Raymond R. Volkas","doi":"10.1016/j.nuclphysb.2025.116850","DOIUrl":null,"url":null,"abstract":"<div><div>We analyse the <em>Z</em> and Higgs boson decays <span><math><mi>Z</mi><mo>→</mo><msup><mrow><mi>ℓ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>ℓ</mi></mrow><mrow><mo>−</mo></mrow></msup></math></span> (<span><math><mi>ℓ</mi><mo>=</mo><mi>e</mi><mo>,</mo><mi>μ</mi><mo>,</mo><mi>τ</mi></math></span>), <span><math><mi>H</mi><mo>→</mo><mi>γ</mi><mi>γ</mi></math></span> and <span><math><mi>H</mi><mo>→</mo><mi>Z</mi><mi>γ</mi></math></span> 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 <span><math><msub><mrow><mi>Z</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span> family symmetry and were recently studied in the context of charged-lepton flavour-violating processes at Belle II and the proposed <span><math><msup><mrow><mi>μ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>+</mo></mrow></msup></math></span> and <span><math><msup><mrow><mi>μ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></math></span> collider known as <em>μ</em>TRISTAN. We find that the future constraints that can be imposed by <span><math><mi>Z</mi><mo>→</mo><msup><mrow><mi>ℓ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>ℓ</mi></mrow><mrow><mo>−</mo></mrow></msup></math></span> 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.</div></div>","PeriodicalId":54712,"journal":{"name":"Nuclear Physics B","volume":"1013 ","pages":"Article 116850"},"PeriodicalIF":2.5000,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nuclear Physics B","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0550321325000598","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, PARTICLES & FIELDS","Score":null,"Total":0}
引用次数: 0
Abstract
We analyse the Z and Higgs boson decays (), and 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 family symmetry and were recently studied in the context of charged-lepton flavour-violating processes at Belle II and the proposed and collider known as μTRISTAN. We find that the future constraints that can be imposed by 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.
期刊介绍:
Nuclear Physics B focuses on the domain of high energy physics, quantum field theory, statistical systems, and mathematical physics, and includes four main sections: high energy physics - phenomenology, high energy physics - theory, high energy physics - experiment, and quantum field theory, statistical systems, and mathematical physics. The emphasis is on original research papers (Frontiers Articles or Full Length Articles), but Review Articles are also welcome.