{"id":43786,"date":"2026-11-13T10:59:21","date_gmt":"2026-11-13T10:59:21","guid":{"rendered":"https:\/\/lamarr-institute.org\/publication\/measurement-of-the-ratio-of-branching-fractions-mathcalbb_c-to-j-psitau-nu_tau-mathcalbb_c-to-j-psimu-nu_mu\/"},"modified":"2026-11-13T10:59:21","modified_gmt":"2026-11-13T10:59:21","slug":"measurement-of-the-ratio-of-branching-fractions-mathcalbb_c-to-j-psitau-nu_tau-mathcalbb_c-to-j-psimu-nu_mu","status":"publish","type":"publication","link":"https:\/\/lamarr-institute.org\/de\/publication\/measurement-of-the-ratio-of-branching-fractions-mathcalbb_c-to-j-psitau-nu_tau-mathcalbb_c-to-j-psimu-nu_mu\/","title":{"rendered":"Measurement of the ratio of branching fractions $\\mathcal{B}(B_c^+ \\to J\/\\psi\\tau^+ \\nu_\\tau)\/\\mathcal{B}(B_c^+ \\to J\/\\psi\\mu^+ \\nu_\\mu)$"},"content":{"rendered":"<p>A measurement of the ratio of semileptonic branching fractions $\\mathcal{R}(J\\psi )$, defined as $\\mathcal{R}(J\/\\psi ) \\equiv \\mathcal{B}(B_c^+ \\to J\/\\psi \\tau^+ \\nu_{\\tau})\/\\mathcal{B}(B_c^+ \\to J\/\\psi \\mu^+ \\nu_{\\mu})$, is reported using a sample of proton-proton collision data corresponding to an integrated luminosity of 5.4 fb$^{-1}$ recorded by the LHCb experiment in 2016&#8211;2018 at a center-of-mass energy of 13 TeV. The measured value is found to be $\\mathcal{R}(J\/\\psi) = 0.51 \\pm 0.12\\text{(stat)} \\pm 0.08\\text{(syst)}$, which is within 1.8 standard deviations of the predictions from the Standard Model assuming lepton flavor universality.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A measurement of the ratio of semileptonic branching fractions $\\mathcal{R}(J\\psi )$, defined as $\\mathcal{R}(J\/\\psi ) \\equiv \\mathcal{B}(B_c^+ \\to J\/\\psi \\tau^+ \\nu_{\\tau})\/\\mathcal{B}(B_c^+ \\to J\/\\psi \\mu^+ \\nu_{\\mu})$, is reported using a sample of proton-proton collision data corresponding to an integrated luminosity of 5.4 fb$^{-1}$ recorded by the LHCb experiment in 2016&#8211;2018 at a center-of-mass energy of 13 TeV. The measured value is found to be $\\mathcal{R}(J\/\\psi) = 0.51 \\pm 0.12\\text{(stat)} \\pm 0.08\\text{(syst)}$, [&hellip;]<\/p>\n","protected":false},"author":14,"featured_media":0,"template":"","meta":{"_acf_changed":false,"footnotes":""},"publication-type":[30],"publication-year":[1680],"class_list":["post-43786","publication","type-publication","status-publish","hentry","publication-type-article","publication-year-1680"],"acf":[],"publishpress_future_workflow_manual_trigger":{"enabledWorkflows":[]},"_links":{"self":[{"href":"https:\/\/lamarr-institute.org\/de\/wp-json\/wp\/v2\/publication\/43786","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\/43786\/revisions"}],"wp:attachment":[{"href":"https:\/\/lamarr-institute.org\/de\/wp-json\/wp\/v2\/media?parent=43786"}],"wp:term":[{"taxonomy":"publication-type","embeddable":true,"href":"https:\/\/lamarr-institute.org\/de\/wp-json\/wp\/v2\/publication-type?post=43786"},{"taxonomy":"publication-year","embeddable":true,"href":"https:\/\/lamarr-institute.org\/de\/wp-json\/wp\/v2\/publication-year?post=43786"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}