{"title":"超对称iii型跷跷板模型中Z规范玻色子衰变的轻子味破坏","authors":"Vael Hajahmad, Murhaf Alsayed Ali","doi":"10.1007/s13538-025-01830-w","DOIUrl":null,"url":null,"abstract":"<div><p>In this study, we investigate the lepton flavor violation (LFV) of <i>Z</i> gauge boson decaying into two different flavor charged leptons <span>\\(\\varvec{Z\\rightarrow } \\varvec{l}_{\\varvec{i}} \\varvec{l}_{\\varvec{j}}\\)</span> (<span>\\(\\varvec{Z\\rightarrow \\tau \\mu }\\)</span>, <span>\\(\\varvec{Z\\rightarrow \\tau e}\\)</span> and <span>\\(\\varvec{Z\\rightarrow \\mu e}\\)</span>). This work is performed in the framework of the constrained minimal supersymmetric standard model (CMSSM) which is extended by the type-III seesaw mechanism. By considering constraints from the current experimental bounds on neutrino and supersymmetric particle masses, we calculate the branching ratios of the LFV of <span>\\(\\varvec{Z}\\)</span> boson decays. The numerical results are found to be <span>\\(\\varvec{1.30 \\times {10}}^{\\varvec{-9}}\\)</span> for both the <span>\\(\\varvec{\\tau \\mu }\\)</span> and <span>\\(\\varvec{\\tau e}\\)</span> decay channels and <span>\\(\\varvec{6.40 \\times {10}}^{\\varvec{-10}}\\)</span> for the <span>\\(\\varvec{\\mu e}\\)</span> channel. After applying the constraints from the experimental bounds on the radiative two body decays <span>\\(\\varvec{l}_{\\varvec{i}}\\varvec{\\rightarrow } \\varvec{l}_{\\varvec{j}} \\varvec{\\gamma }\\)</span>, the branching ratios of the LFV of <span>\\(\\varvec{Z}\\)</span> boson decays get an additional suppression of <span>\\(\\varvec{10}^{\\varvec{-3}}\\)</span> for the <span>\\(\\varvec{\\tau \\mu }\\)</span> and <span>\\(\\varvec{\\tau e}\\)</span> decay channels and <span>\\(\\varvec{10}^{\\varvec{-8}}\\)</span> for the <span>\\(\\varvec{\\mu e}\\)</span> channel. Our prediction of the branching ratios is several orders of magnitude below the current experimental bounds.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 5","pages":""},"PeriodicalIF":1.7000,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Lepton Flavor Violation of Z Gauge Boson Decays in Supersymmetric Type-III Seesaw Model\",\"authors\":\"Vael Hajahmad, Murhaf Alsayed Ali\",\"doi\":\"10.1007/s13538-025-01830-w\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>In this study, we investigate the lepton flavor violation (LFV) of <i>Z</i> gauge boson decaying into two different flavor charged leptons <span>\\\\(\\\\varvec{Z\\\\rightarrow } \\\\varvec{l}_{\\\\varvec{i}} \\\\varvec{l}_{\\\\varvec{j}}\\\\)</span> (<span>\\\\(\\\\varvec{Z\\\\rightarrow \\\\tau \\\\mu }\\\\)</span>, <span>\\\\(\\\\varvec{Z\\\\rightarrow \\\\tau e}\\\\)</span> and <span>\\\\(\\\\varvec{Z\\\\rightarrow \\\\mu e}\\\\)</span>). This work is performed in the framework of the constrained minimal supersymmetric standard model (CMSSM) which is extended by the type-III seesaw mechanism. By considering constraints from the current experimental bounds on neutrino and supersymmetric particle masses, we calculate the branching ratios of the LFV of <span>\\\\(\\\\varvec{Z}\\\\)</span> boson decays. The numerical results are found to be <span>\\\\(\\\\varvec{1.30 \\\\times {10}}^{\\\\varvec{-9}}\\\\)</span> for both the <span>\\\\(\\\\varvec{\\\\tau \\\\mu }\\\\)</span> and <span>\\\\(\\\\varvec{\\\\tau e}\\\\)</span> decay channels and <span>\\\\(\\\\varvec{6.40 \\\\times {10}}^{\\\\varvec{-10}}\\\\)</span> for the <span>\\\\(\\\\varvec{\\\\mu e}\\\\)</span> channel. After applying the constraints from the experimental bounds on the radiative two body decays <span>\\\\(\\\\varvec{l}_{\\\\varvec{i}}\\\\varvec{\\\\rightarrow } \\\\varvec{l}_{\\\\varvec{j}} \\\\varvec{\\\\gamma }\\\\)</span>, the branching ratios of the LFV of <span>\\\\(\\\\varvec{Z}\\\\)</span> boson decays get an additional suppression of <span>\\\\(\\\\varvec{10}^{\\\\varvec{-3}}\\\\)</span> for the <span>\\\\(\\\\varvec{\\\\tau \\\\mu }\\\\)</span> and <span>\\\\(\\\\varvec{\\\\tau e}\\\\)</span> decay channels and <span>\\\\(\\\\varvec{10}^{\\\\varvec{-8}}\\\\)</span> for the <span>\\\\(\\\\varvec{\\\\mu e}\\\\)</span> channel. Our prediction of the branching ratios is several orders of magnitude below the current experimental bounds.</p></div>\",\"PeriodicalId\":499,\"journal\":{\"name\":\"Brazilian Journal of Physics\",\"volume\":\"55 5\",\"pages\":\"\"},\"PeriodicalIF\":1.7000,\"publicationDate\":\"2025-06-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Brazilian Journal of Physics\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s13538-025-01830-w\",\"RegionNum\":4,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"PHYSICS, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Brazilian Journal of Physics","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1007/s13538-025-01830-w","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, MULTIDISCIPLINARY","Score":null,"Total":0}
Lepton Flavor Violation of Z Gauge Boson Decays in Supersymmetric Type-III Seesaw Model
In this study, we investigate the lepton flavor violation (LFV) of Z gauge boson decaying into two different flavor charged leptons \(\varvec{Z\rightarrow } \varvec{l}_{\varvec{i}} \varvec{l}_{\varvec{j}}\) (\(\varvec{Z\rightarrow \tau \mu }\), \(\varvec{Z\rightarrow \tau e}\) and \(\varvec{Z\rightarrow \mu e}\)). This work is performed in the framework of the constrained minimal supersymmetric standard model (CMSSM) which is extended by the type-III seesaw mechanism. By considering constraints from the current experimental bounds on neutrino and supersymmetric particle masses, we calculate the branching ratios of the LFV of \(\varvec{Z}\) boson decays. The numerical results are found to be \(\varvec{1.30 \times {10}}^{\varvec{-9}}\) for both the \(\varvec{\tau \mu }\) and \(\varvec{\tau e}\) decay channels and \(\varvec{6.40 \times {10}}^{\varvec{-10}}\) for the \(\varvec{\mu e}\) channel. After applying the constraints from the experimental bounds on the radiative two body decays \(\varvec{l}_{\varvec{i}}\varvec{\rightarrow } \varvec{l}_{\varvec{j}} \varvec{\gamma }\), the branching ratios of the LFV of \(\varvec{Z}\) boson decays get an additional suppression of \(\varvec{10}^{\varvec{-3}}\) for the \(\varvec{\tau \mu }\) and \(\varvec{\tau e}\) decay channels and \(\varvec{10}^{\varvec{-8}}\) for the \(\varvec{\mu e}\) channel. Our prediction of the branching ratios is several orders of magnitude below the current experimental bounds.
期刊介绍:
The Brazilian Journal of Physics is a peer-reviewed international journal published by the Brazilian Physical Society (SBF). The journal publishes new and original research results from all areas of physics, obtained in Brazil and from anywhere else in the world. Contents include theoretical, practical and experimental papers as well as high-quality review papers. Submissions should follow the generally accepted structure for journal articles with basic elements: title, abstract, introduction, results, conclusions, and references.