Constraints on s→dγ from radiative hyperon and kaon decays

The quark-level process b→sγ has been used extensively to place constraints on new interactions. These same interactions can also be constrained from the enhancement they induce in the quark-level s→dγ transition, to the extent that the short distance contributions can be separated from the long distance contributions. We parametrize what is known about the long distance amplitudes and subtract it from the data in radiative hyperon and kaon decays to constrain new interactions. These constraints complement existing ones from other rare processes although in most cases they are weaker. (c) 2000 The American Physical Society