Non-mesonic weak decay of Lambda hypernuclei within a nuclear matter framework

摘要

The non-mesonic weak decay of Lambda hypernuclei is studied using nuclear matter. We have developed a formalism which gives a microscopic interpretation of the process of emission of particles originated in this decay. More specifically, our scheme provides a unified treatment of Gamma(Lambda N -> NN) and N-N (N-NN), the A non-mesonic weak decay widths and the number of emitted particles (pair of particles) of kind N (NN), respectively. We have also evaluated for the first time the quantum interference terms between the n- and p-induced weak decay amplitudes. Explicit expressions for N-N and N-NN are shown within the ring approximation. Using the local density approximation together with the ring approximation, we report results for the decay of the C-12(Lambda) hypernucleus. We have obtained values for the ratio N-n/N-p (N-nn/N-np) A in the range 1.4-1.6 (0.2-0.3), where no energy threshold have been employed. The n- and p-induced interference terms modify in less than similar to 3% these results. (c) 2006 Elsevier B.V. All rights reserved.