An EFT for the weak ΛN interaction

Abstract

The nonleptonic weak | Δ S | = 1 ΛN 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 ( π and K), while the short-range potential is parametrized in terms of lowest-order contact terms obtained from the most general non-derivative local four-fermion interaction. Fitting to available weak hypernuclear decay rates for 5 Λ He, 11 Λ B and 12 Λ C yields reasonable values for the low-energy constants.