
Precision measurements of hyperon radiative decay Σ+→pγ
The BESIII collaboration has reported the first absolute branching fraction and decay asymmetry of Σ+→pγ with 10 billion J/ψ data. The measured value of the branching fraction is lower than the world average by 4.2 standard deviations. Both the branching fraction and decay asymmetry parameter are measured with the most precision to date. The results have been published recently in Physics Review Letters [Phys. Rev. Lett. 130, 211901 (2023)].