
Precision measurements of hyperon radiative decay Λ → nγ
The BESIII collaboration has reported the first absolute branching fraction and decay asymmetry of Λ → nγ via J/ψ→ΛΛbar process with 10 billion J/ψ data. This is the first measurement of radiative hyperon decays at an electron-positron collider experiment. The measured value of the branching fraction with improved precision, is 5.6 standard deviations different from the PDG average value. The results have been published in Physics Review Letter [Phys. Rev. Lett. 129, 212002 (2022)].