Weak radiative hyperon decays in quark model

Weak radiative hyperon decays are considered in the framework of a quark model. The phenomenological model includes 1-quark transitions with the effective $sd\gamma$-vertex and 2-quark ones with the W-exchange $s+u\to u+d+\gamma$ and turns out to describe well the data and gives predictions for asymmetry of the decays $\Lambda\to n+\gamma$ and $\Xi^-\to \Sigma^- +\gamma$