Ablikim, M.Achasov, M.N.Adlarson, P.Afedulidis, O.Ai, X.C.Aliberti, R.Çetin, Serkant Ali2024-05-192024-05-1920240370-2693https://doi.org/10.1016/j.physletb.2024.138614https://hdl.handle.net/20.500.12713/4233A massless particle beyond the Standard Model is searched for in the two-body decay ?+?p+invisible using (1.0087±0.0044)×1010 J/? events collected at a center-of-mass energy of s=3.097GeV with the BESIII detector at the BEPCII collider. No significant signal is observed, and the upper limit on the branching fraction B(?+?p+invisible) is determined to be 3.2×10?5 at the 90% confidence level. This is the first search for a flavor-changing neutral current process with missing energy in hyperon decays which plays an important role in constraining new physics models. © 2024 The Author(s)eninfo:eu-repo/semantics/openAccessBesıııBsm ParticleFcnc ProcessHyperon DecayArticle8522-s2.0-8518954976710.1016/j.physletb.2024.138614Q1