Constraints on s -> d gamma from radiative hyperon and kaon decays - art. no. 075003

The quark-level process b --> s gamma has been used extensively to place co nstraints on new interactions. These same interactions can also be constrai ned from the enhancement they induce in the quark-level s --> d gamma trans ition, to the extent that the short distance contributions can be separated from the long distance contributions. We parametrize what is known about t he long distance amplitudes and subtract it from the data in radiative hype ron and kaon decays to constrain new interactions. These constraints comple ment existing ones from other rare processes although in most cases they ar e weaker.