Ablikim, M.Achasov, M. N.Adlarson, P.Aliberti, R.Amoroso, A.An, M. R.Çetin, Serkant Ali2024-05-192024-05-1920232470-00102470-0029https://doi.org10.1103/PhysRevD.108.052001https://hdl.handle.net/20.500.12713/5820Based on (448.1 +/- 2.9) x 106 psi(3686) events collected with the BESIII detector operating at the BEPCII collider, the decay psi(3686) -> phi K0SK0S is observed for the first time. Taking the interference between psi(3686) decay and continuum production into account, the branching fraction of this decay is measured to be B(psi (3686) -> phi K0SK0S) = (3.53 +/- 0.20 +/- 0.21) x 10-5, where the first uncertainty is statistical and the second is systematic. Combining with the world average value for B(J=psi -> phi K0SK0S), the ratio B(psi (3686) -> phi K0SK0S)=B(J=psi -> phi K0SK0S) is determined to be (6.0 +/- 1.6)%, which is sup -pressed relative to the 12% rule.eninfo:eu-repo/semantics/openAccess[No Keywords]Article1085WOS:0010910594000012-s2.0-85172768968N/A10.1103/PhysRevD.108.052001Q1