A theoretical overview of hypernuclear weak decay

The physics of the weak decay of hypernuclei is briefly reviewed from a theoretical point of view. Special regard is devoted to the recent progress concerning the determination of the non-mesonic decay widths and the asymmetry parameters. Convincing evidence has been achieved for a solution of the long-standing puzzle on the ratio Γn/Γp. Very recently, it has been shown that the exchange of a ππ pair in the weak mechanism plays a crucial role in explaining the discrepancies between theory and experiment on the decay asymmetries.