Hyperon Weak Radiative Decay

Peng-Yu Niu , Jean-Marc Richard (1) , Qian Wang , Qiang Zhao

1 IP2I Lyon - Institut de Physique des 2 Infinis de Lyon

We revisit the hyperon weak radiative decays in the framework of the non-relativistic constituent quark model. This study confirms the nonlocal feature of the hyperon weak radiative transition operators, which are dominated by the pole terms, and an overall self-consistent description of the available experimental data for the Cabibbo-favored hyperon weak radiative decays is presented. It provides a natural mechanism for evading the Hara theorem, where sizeable parity-violating contributions can come from the intermediate orbital excitations. Cancellations between pole terms also explain the significant SU(3) flavor symmetry breaking manifested by the experimental data. We also discuss several interesting selection rules arising from either the electromagnetic or the weak interaction vertices. These features suggest nontrivial relations among various hyperon decays.

Mots clés: hyperon: decay; hyperon: radiative decay; symmetry breaking: flavor; quark model: constituent; operator: transition; flavor: SU(3); pole; weak interaction; nonrelativistic; electromagnetic; selection rule; excited state; nonlocal; parity: violation; effective Hamiltonian; Cabibbo angle; Sigma+ --> p photon; Lambda --> n photon; Xi0 --> Lambda photon; Xi0 --> Sigma0 photon; Sigma0 --> n photon

Domaines: Physique des Hautes Energies - Phénoménologie [hep-ph]

Peng-Yu Niu, Jean-Marc Richard, Qian Wang, Qiang Zhao. Hyperon Weak Radiative Decay. Chin.Phys.C, 2021, 45 (1), pp.013101. ⟨10.1088/1674-1137/abc067⟩. ⟨hal-02914458⟩