Asymmetries in the weak decay of polarized hypernuclei

Polarization observables and decay rates are evaluated for the nonmesonic weak decay of hypernuclei in a relativistic nuclear model. The single-particle bound and scattering states are obtained by solving the Dirac equation with large potentials. The total decay rates are very sensitive to ΛN short-range correlations in the initial state. The experimental total and partial decay rates of 5ΛHe, 11ΛB and 12ΛC cannot be reproduced with only pion- and kaon-exchange in the process ΛN→NN. However, the proton asymmetries in the decay of 11ΛB vector and 12ΛC vector are in rough agreement with preliminary experimental data from KEK. These polarization observables are found to be sensitive to the final-state interaction of the ejected nucleons. (orig.)