{"id":32492,"date":"2026-01-21T17:02:02","date_gmt":"2026-01-21T17:02:02","guid":{"rendered":"https:\/\/lamarr-institute.org\/publication\/measurement-of-cp-violation-in-b0to-psitoellell-k0_mathrmsto-pipi-decays\/"},"modified":"2026-06-08T13:20:46","modified_gmt":"2026-06-08T13:20:46","slug":"measurement-of-cp-violation-in-b0to-psitoellell-k0_mathrmsto-pipi-decays","status":"publish","type":"publication","link":"https:\/\/lamarr-institute.org\/de\/publication\/measurement-of-cp-violation-in-b0to-psitoellell-k0_mathrmsto-pipi-decays\/","title":{"rendered":"Measurement of $CP$ Violation in $B^0\\to \\psi(\\to\\ell^+\\ell^-)K^0_\\mathrm{S}(\\to \\pi^+\\pi^-)$ Decays"},"content":{"rendered":"<p>A measurement of time-dependent $CP$ violation in the decays of $B^0$ and $\\bar{B}^0$ mesons to the final states $J\/\\psi (\\to \\mu^+ \\mu^-) K^0_S$, $\\psi(2S) (\\to \\mu^+ \\mu^-) K^0_S$ and $J\/\\psi (\\to e^+ e^-) K^0_S$ with $K^0_S \\to \\pi^+ \\pi^-$ is presented. The data correspond to an integrated luminosity of 6 fb$^{-1}$ collected at a center-of-mass energy of $\\sqrt{s} = 13 \\, \\text{TeV}$ with the LHCb detector. The $CP$-violation parameters are measured to be $S_{\\psi K^0_S} = 0.717 \\pm 0.013 \\, \\text{(stat)} \\pm 0.008 \\, \\text{(syst)}$ and $C_{\\psi K^0_S} = 0.008 \\pm 0.012 \\, \\text{(stat)} \\pm 0.003 \\, \\text{(syst)}$. This measurement of $S_{\\psi K^0_S}$ represents the most precise single measurement of the CKM angle $\\beta$ to date and is more precise than the current world average. In addition, measurements of the $CP$-violation parameters of the individual channels are reported and a combination with the LHCb Run 1 measurements is performed.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A measurement of time-dependent $CP$ violation in the decays of $B^0$ and $\\bar{B}^0$ mesons to the final states $J\/\\psi (\\to \\mu^+ \\mu^-) K^0_S$, $\\psi(2S) (\\to \\mu^+ \\mu^-) K^0_S$ and $J\/\\psi (\\to e^+ e^-) K^0_S$ with $K^0_S \\to \\pi^+ \\pi^-$ is presented. The data correspond to an integrated luminosity of 6 fb$^{-1}$ collected at a center-of-mass energy of $\\sqrt{s} = 13 \\, \\text{TeV}$ with the LHCb detector. The $CP$-violation parameters are [&hellip;]<\/p>\n","protected":false},"author":12,"featured_media":0,"template":"","meta":{"_acf_changed":false,"footnotes":""},"publication-type":[30],"class_list":["post-32492","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\/32492","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\/12"}],"version-history":[{"count":0,"href":"https:\/\/lamarr-institute.org\/de\/wp-json\/wp\/v2\/publication\/32492\/revisions"}],"wp:attachment":[{"href":"https:\/\/lamarr-institute.org\/de\/wp-json\/wp\/v2\/media?parent=32492"}],"wp:term":[{"taxonomy":"publication-type","embeddable":true,"href":"https:\/\/lamarr-institute.org\/de\/wp-json\/wp\/v2\/publication-type?post=32492"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}