An EFT for the weak $\Lambda N$ interaction

Abstract

The nonleptonic weak $|\Delta S|=1$ $\Lambda N$ 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 ($\pi$ 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 ${}_{\Lambda }^5\mathrm{He}$, ${}_{\Lambda }^{11}\mathrm{B}$ and ${}_{\Lambda }^{12}\mathrm{C}$ yields reasonable values for the low-energy constants.

Comments: Contribution to the Proceedings of the VIII International Conference on Hypernuclear and Strange Particle Physics, HYP03, revised version. 10 pages. Uses espcrc1.sty