Radiative weak decays of uncharmed hyperons

Abstract

By assuming that the anomalous electromagnetic (EM) Hamiltonian transforms like the T11+bT22 component of an octet, the authors explain the large asymmetry parameter for Sigma + to p gamma decay. By employing the non-exoticity of intermediate states and s-u-channel symmetry of the weak Hamiltonian, they obtain several new sum rules relating decay amplitudes in different charge sectors. Branching fractions and asymmetry parameters for these decays are also predicted. The calculated Xi - to sigma - gamma decay rate is in agreement with the measured upper limit.