Mesonic and non-mesonic decay widths of Λ4H and Λ4He
Abstract
Results are reported on precise measurements of the weak-decay processes of Λ4H and Λ4He hypernuclei formed via the 4He(K-stopped,π-) reaction. The lifetimes of Λ4H (194+24-26ps) and Λ4He (256+/-27ps) were obtained. The π0 and π- decay branching ratios of Λ4He (0.515+/-0.035 and 0.322+/-0.034, respectively) were precisely determined and they are compared with recent theoretical estimates and related experimental values. Our results favor a Λ-nucleus interaction with an inner repulsive core. The non-mesonic weak decay widths of Λ4H and Λ4He are reexamined on the basis of our measurements and updated knowledge of the mesonic decay processes. It is found that the non-mesonic decay of Λ4He predominantly takes place via the Λ+p-->n+p process.
- Publication:
-
Nuclear Physics A
- Pub Date:
- August 1998
- DOI:
- 10.1016/S0375-9474(98)00281-4
- Bibcode:
- 1998NuPhA.639..251O