{"id":2245,"date":"2025-05-21T01:41:11","date_gmt":"2025-05-20T17:41:11","guid":{"rendered":"http:\/\/web.tdli.sjtu.edu.cn\/kimsiang84\/?page_id=2245"},"modified":"2025-05-21T01:41:11","modified_gmt":"2025-05-20T17:41:11","slug":"muonium","status":"publish","type":"page","link":"https:\/\/web.tdli.sjtu.edu.cn\/kimsiang84\/muonium\/","title":{"rendered":"Muonium"},"content":{"rendered":"\n

What is a Muonium (\u03bc+<\/sup> e–<\/sup>)?<\/strong><\/h2>\n\n\n\n
  • Bound state of positive muon \u03bc +<\/sup> and electron e –<\/sup><\/li>
  • The lightest hydrogen-like atom<\/li>
  • Lifetime: limited by 2.2 \u03bcs (lifetime of muon) [2]<\/sup><\/li>
  • Two leptons system with two different particle generations ( \u03bc +<\/sup> e –<\/sup> )<\/li>
  • Suitable for QED precision measurements<\/li>
  • Produced by injecting \u03bc +<\/sup> into silica aerogel [3]<\/sup><\/li><\/ul>\n\n\n\n
    • \"\"<\/figure><\/li>
    • \"\"<\/figure><\/li><\/ul><\/figure>\n\n\n\n

      Why study Muonium?<\/strong><\/h2>\n\n\n\n

      Precision test of quantum electrodynamics theory [2]<\/sup><\/h3>\n\n\n\n
      • Ground state hyperfine splitting \u0394\ud835\udf08HFS <\/sub>: muon mass m\u03bc <\/sub>(\u0394\ud835\udf08HFS<\/sub> \u221d 1\/m\u03bc<\/sub> )<\/li>
      • Ground state hyperfine splitting \u0394\ud835\udf08HFS<\/sub> : fine structure constant \u03b1<\/li>
      • Muonium 1S-2S transition spectroscopy [4] <\/sup>:<\/strong> me<\/sub>\/m\u03bc<\/sub><\/li><\/ul>\n\n\n\n
        \"\"<\/figure><\/div>\n\n\n\n

        Tests of CPT symmetry [5]<\/sup><\/h3>\n\n\n\n
        • 1S-2S transition spectroscopy of muonium and antimuonium<\/li><\/ul>\n\n\n\n

          Discovering new physics beyond the Standard Model (BSM) [6]<\/sup><\/sup><\/h3>\n\n\n\n
          • Lepton-flavor-violating (muonium-to-antimuonium conversion)<\/li><\/ul>\n\n\n\n

            Muonium-to-Antimuonium ConversionExperiment (MACE) [6]<\/sup><\/strong><\/h2>\n\n\n\n
            • A charged lepton flavour violation phenomena<\/li>
            • This conversion is forbidden in SM<\/li>
            • Current limit: (MACS experiment at PSI in 1999): P \u2272 8.3 \u00d7 10-11<\/sup> (90% C.L.)<\/li>
            • MACE seeks to detect or place limits on this rare process with a conversion probability exceeding 10-13<\/sup><\/li><\/ul>\n\n\n\n
              \"\"<\/figure><\/div>\n\n\n\n

              Testing Antimatter Gravity with Muonium [7]<\/sup><\/strong><\/h2>\n\n\n\n
              • Measuring muonium’s gravitational interaction with ordinary matter<\/li>
              • Two different approaches for a muonium gravity experiment are being considered:
                • Search for an annual modulation of the muonium (1S-2S) transition frequency<\/li><\/ul>
                  • Use a high quality muonium beam passing through a Mach-Zehnder atom interferometer<\/li><\/ul><\/li><\/ul>\n\n\n\n
                    \"\"<\/figure><\/div>\n\n\n\n

                    References<\/h2>\n\n\n\n
                    1. Hughes, V. W., McColm, D. W., Ziock, K., & Prepost, R., Phys. Rev. Lett.<\/em>, 5<\/strong>(2) (1960)<\/li>
                    2. Willmann, L., & Jungmann, K., SciPost Phys. Proc <\/em>(2021)<\/li>
                    3. Otani, M., Muon cooling and acceleration, AAPPS Bull<\/em>, 32<\/strong>, 6 (2022)<\/li>
                    4. Laporta, S., & Remiddi, E., Quantum Electrodynamics and its Precision Tests, Encyclopedia of Mathematical Physics<\/em>, 1<\/strong> (2006)<\/li>
                    5. Gomes, A. H., Kosteleck\u00fd, V. A., & Vargas, A. J., Phys. Rev<\/em>., 90<\/strong>(7) (2014)<\/li>
                    6. Bai, A. Y. et al., Conceptual Design of the Muonium-to-Antimuonium Conversion Experiment (MACE) (2024)<\/li>
                    7. Kirch, K., & Khaw, K. S., Testing antimatter gravity with muonium, International Journal of Modern Physics: Conference Series<\/em>, 30 <\/strong>(2014)<\/li><\/ol>\n\n\n\n

                      <\/p>\n","protected":false},"excerpt":{"rendered":"

                      What is a Muonium (\u03bc+ e–)? Bound state of positive muon \u03bc + and electron e – The lightest hydrogen-like […]<\/p>\n","protected":false},"author":3,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"class_list":["post-2245","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/web.tdli.sjtu.edu.cn\/kimsiang84\/wp-json\/wp\/v2\/pages\/2245","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/web.tdli.sjtu.edu.cn\/kimsiang84\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/web.tdli.sjtu.edu.cn\/kimsiang84\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/web.tdli.sjtu.edu.cn\/kimsiang84\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/web.tdli.sjtu.edu.cn\/kimsiang84\/wp-json\/wp\/v2\/comments?post=2245"}],"version-history":[{"count":16,"href":"https:\/\/web.tdli.sjtu.edu.cn\/kimsiang84\/wp-json\/wp\/v2\/pages\/2245\/revisions"}],"predecessor-version":[{"id":2261,"href":"https:\/\/web.tdli.sjtu.edu.cn\/kimsiang84\/wp-json\/wp\/v2\/pages\/2245\/revisions\/2261"}],"wp:attachment":[{"href":"https:\/\/web.tdli.sjtu.edu.cn\/kimsiang84\/wp-json\/wp\/v2\/media?parent=2245"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}