Weak decay of $\Lambda$ in nuclei: Quarks versus mesons

Abstract Decays of Λ in nuclei, non-mesonic modes, are studied by using the ΛN→NN weak transition potential derived from the meson exchange mechanism and the direct quark mechanism. The decay rates are calculated both for the Λ in symmetric nuclear matter and light hypernuclei. We consider the exchange of six mesons ( π,K,η,ρ,ω,K ∗ ). The form factor in the meson exchange mechanism and short-range correlation are carefully studied.