Ablikim, M.Achasov, M. N.Adlarson, P.Albrecht, M.Aliberti, R.Amoroso, A.Çetin, Serkant Ali2024-05-192024-05-1920230031-90071079-7114https://doi.org10.1103/PhysRevLett.130.211901https://hdl.handle.net/20.500.12713/5857Using (10 087 +/- 44) x 10(6) J/psi events collected with the BESIII detector, the radiative hyperon decay Sigma(+) -> p gamma is studied at an electron-positron collider experiment for the first time. The absolute branching fraction is measured to be (0.996 +/- 0.021(stat) +/- 0.018(syst)) x 10(-3), which is lower than its world average value by 4.2 standard deviations. Its decay asymmetry parameter is determined to be -0.652 +/- 0.056(stat) +/- 0.020(syst). The branching fraction and decay asymmetry parameter are the most precise to date, and the accuracies are improved by 78% and 34%, respectively.eninfo:eu-repo/semantics/openAccessRadiative Hyperon DecaysBranching RatioAsymmetry ParameterArticle1302137295102WOS:0010205821000012-s2.0-85161644119N/A10.1103/PhysRevLett.130.211901Q1