Λ hypernuclear nonmesonic lifetimes are calculated in the framework of the hybrid quark-hadron model, for both infinite nuclear matter and for a finite nucleus ${}_{\mathrm{\Lambda }}{}^{12}{}_{}{}^{}\mathrm{C}$. For nuclear matter, an approximate solution of the Bethe-Goldstone equation is used for the initial state ΛN cluster wave function. For ${}_{\mathrm{\Lambda }}{}^{12}{}_{}{}^{}\mathrm{C}$ a shell model wave function is used. An eikonal approximation is used to represent final state interactions. It is shown that with an effective weak quark Hamiltonian explicitly constructed to be consistent with the ΔI=1/2 rule the ${}_{\mathrm{\Lambda }}{}^{12}{}_{}{}^{}\mathrm{C}$ nonmesonic width is about 1.3 times the free Λ width, which is consistent with a recent experimental measurement.

• Received 10 September 1985

DOI:https://doi.org/10.1103/PhysRevC.33.608