Violation of the ∆I=1/2 rule in the nonmesonic weak decay of hypernuclei

Violations of the ∆I=1/2 rule are investigated in the nonmesonic weak hypernuclear decay using a weak ΛN→NN transition potential based on meson exchange. While the weak ∆I=3/2 couplings of baryons to pseudoscalar mesons are known to be very small, the analogous couplings of baryons to vector mesons are not known experimentally. These couplings have been evaluated using the factorization approximation and are found to produce potentially significant changes in the predictions for hypernuclear decay observables in the case of 12 Λ C. Within the uncertainties of the factorization approximation we find that the proton-induced rate is affected by at most 10%, while the e-mail address: [email protected]