2026/08/04 by Kaiwen Chen, Lin Qiu, Jin Sun +2
Physics and Astronomy · #hep-ph
6 pages, 3 tables
arxiv created 2026/08/04 · arxiv updated 2026/08/05
We present a broken SU(3) flavor analysis of weak radiative decays of spin-1/2 hyperons, incorporating current-current and electromagnetic-penguin contributions as well as charge- and mass-insertion effects. Six independent reduced amplitudes describe all decay channels, while a minimal relation between the parity-conserving and parity-violating form factors reduces to eight free parameters. A global fit to the ten available observables yields χ2/d.o.f.=0.98 and accommodates the large negative asymmetry in Σ+→ pγ. The resulting nonzero effective form factor gb8 provides a possible flavor-symmetry realization of the parity-violating amplitude while remaining compatible with Hara's theorem, which constrains the current-current contribution in the exact symmetry limit. Our analysis favors a sizable negative value of αγ(Ξ- → Σ- γ), which differs from the current experimental result by approximately 1.3σ. Future precision measurements of this observable will provide a decisive test of this prediction.