E2 M1 MIXING-RATIO OF DELTA-]N-GAMMA AND HYPERON RESONANCE RADIATIVE DECAY/

We complete the leading contribution to the E2/M1 mixing ratio of the decay DELTA-->Ngamma in heavy baryon chiral perturbation theory. We fi nd the mixing ratio to be 4% less than or similar to \delta(E2/M1)\ le ss than or similar to 11%, much larger than estimates based on the qua rk model and other hadronic models. We also compute the mixing ratio f or the radiative decay of the hyperon resonances. The decays SIGMA+ - -> SIGMA+gamma and XI- --> XI- gamma provide a particularly sensitive probe of deviations from heavy baryon spin-flavour SU(6).