The $ΛΛ\to YN$ Weak Transition in Double-$Λ$ Hypernuclei

Abstract

We calculate the $ΛΛ\to YN$ transition rate of ${^{\phantomΛ6}_{ΛΛ}}$He by the hybrid picture, the $π$ and $K$ exchanges plus the direct quark processes. It is found that the hyperon-induced decay is weaker than the nucleon-induced decay, but the former may reveal the short-range mechanism of the weak transition and also give a clear signal of the strong $ΔI=3/2$ transition. The $ΛΛ\to Y N$ transition in double-$Λ$ hypernucleus is complement to the $ΛN \to NN$ transition as it occurs only in the J=0 channel, while the J=1 transition is dominant in the $ΛN \to NN$ case.

9 pages