{"id":32251,"date":"2026-01-21T17:01:33","date_gmt":"2026-01-21T17:01:33","guid":{"rendered":"https:\/\/lamarr-institute.org\/publication\/observation-of-the-very-rare-sum-to-p-mu-mu-decay\/"},"modified":"2026-09-17T11:22:18","modified_gmt":"2026-09-17T11:22:18","slug":"observation-of-the-very-rare-sum-to-p-mu-mu-decay","status":"publish","type":"publication","link":"https:\/\/lamarr-institute.org\/de\/publication\/observation-of-the-very-rare-sum-to-p-mu-mu-decay\/","title":{"rendered":"Observation of the very rare $\\sum^+ \\to p \\mu^+ \\mu^-$ decay"},"content":{"rendered":"<p>The first observation of the $\\sum^+ \\to p \\mu^+ \\mu^-$ decay is reported with high significance using proton-proton collision data, corresponding to an integrated luminosity of 5.4 fb$^{-1}$, collected with the {LHCb} detector at a center-of-mass energy of 13 {TeV}. A yield of 237$\\pm$16 $\\sum^+ \\to p \\mu^+ \\mu^-$ decays is obtained, where the uncertainty is statistical only. A branching fraction of $(1.08 \\pm 0.17) \\times 10^{-8}$ is measured, where the uncertainty includes statistical and systematic sources. No evidence of resonant structures is found in the dimuon invariant-mass distribution. All results are compatible with standard model expectations. This represents the rarest decay of a baryon ever observed.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The first observation of the $\\sum^+ \\to p \\mu^+ \\mu^-$ decay is reported with high significance using proton-proton collision data, corresponding to an integrated luminosity of 5.4 fb$^{-1}$, collected with the {LHCb} detector at a center-of-mass energy of 13 {TeV}. A yield of 237$\\pm$16 $\\sum^+ \\to p \\mu^+ \\mu^-$ decays is obtained, where the uncertainty is statistical only. A branching fraction of $(1.08 \\pm 0.17) \\times 10^{-8}$ is measured, where [&hellip;]<\/p>\n","protected":false},"author":14,"featured_media":0,"template":"","meta":{"_acf_changed":false,"footnotes":""},"publication-type":[30],"class_list":["post-32251","publication","type-publication","status-publish","hentry","publication-type-article"],"acf":[],"publishpress_future_workflow_manual_trigger":{"enabledWorkflows":[]},"_links":{"self":[{"href":"https:\/\/lamarr-institute.org\/de\/wp-json\/wp\/v2\/publication\/32251","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lamarr-institute.org\/de\/wp-json\/wp\/v2\/publication"}],"about":[{"href":"https:\/\/lamarr-institute.org\/de\/wp-json\/wp\/v2\/types\/publication"}],"author":[{"embeddable":true,"href":"https:\/\/lamarr-institute.org\/de\/wp-json\/wp\/v2\/users\/14"}],"version-history":[{"count":0,"href":"https:\/\/lamarr-institute.org\/de\/wp-json\/wp\/v2\/publication\/32251\/revisions"}],"wp:attachment":[{"href":"https:\/\/lamarr-institute.org\/de\/wp-json\/wp\/v2\/media?parent=32251"}],"wp:term":[{"taxonomy":"publication-type","embeddable":true,"href":"https:\/\/lamarr-institute.org\/de\/wp-json\/wp\/v2\/publication-type?post=32251"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}