AN -> NN weak interaction in effective-field theory

The nonleptonic weak $\ensuremath{\mid}\ensuremath{\Delta}S\ensuremath{\mid}=1\phantom{\rule{0.3em}{0ex}}\ensuremath{\Lambda}N$ interaction, responsible for the dominant nonmesonic decay of all but the lightest hypernuclei, is studied in the framework of an effective-field theory. The long-range physics is described through tree-level exchange of the SU(3) Goldstone bosons, while the short-range potential is parametrized in terms of the lowest-order contact terms. We obtain reasonable fits to available weak hypernuclear decay rates and quote the values for the parity-violating asymmetry as predicted by the present effective-field theory.