Measurement of the hyperon weak radiative decay Ξ⁰→γΣ⁰ at BESIII

2025/12/03 by BESIII Collaboration, Ablikim, M., Achasov, M. N. +615
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex)

paper · doi:10.48550/arxiv.2512.03877

Abstract

The hyperon weak radiative decay Ξ⁰→γΣ⁰ is measured via the process J/ψ→Ξ⁰Ξ⁰. The absolute branching fraction of Ξ⁰→γΣ⁰ is determined to be (3.69± 0.21_stat±0.12_syst)× 10^-3, based on (10.087± 0.044)× 10⁹ J/ψ events collected with the BESIII detector operating at the BEPCII collider. The decay asymmetry parameter is measured, with a complete angular analysis of the cascade decay chain, to be α_γ = -0.807± 0.095_stat± 0.011_syst.

Citations

• Status and prospect of weak radiative hyperon decays
• Coherent Exclusive Exponentiation for Precision Monte Carlo Calculations of Fermion Pair Production / Precision Predictions for (Un)stable W+W- Pairs
• Photos — a universal Monte Carlo for QED radiative corrections in decays

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