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Transitions of two baryons to the H dibaryon in nuclei

We calculate the suppression in the rate at which two baryons in a nucleus (viz., nucleons or $Λ$'s) convert to an H dibaryon, using an Isgur-Karl wavefunction for quarks in the baryons and H, and a Bethe-Goldstone wavefunction for the baryons in the nucleus. If $r_H \lsi 1/3~ r_N$, we find $τ_{A_{ΛΛ}\to A'_H}\gsi τ_Λ$ and the observation of $Λ$ decays from double-$Λ$ hypernuclei does not exclude the existence of the H. If $m_H < 2 m_p$, nuclei are unstable but have very long lifetimes. For reasonable values of $r_H$ and the nuclear wavefunction, the lifetime can be long enough to evade anticipated SuperK limits $τ_{A_{NN}\to A'_H}\gsi {\rm few} 10^{29}$ yr, or short enough to be observed. An analysis of SuperK data to look for this possibility should be undertaken.