Transitions of two baryons to the H dibaryon in nuclei

Abstract

We calculate the suppression in the rate at which two baryons in a nucleus (viz., nucleons or $\Lambda$'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 $r_H\text{lsi}1/3r_N$, we find ${\tau }_{A_{\Lambda \Lambda }\to A_H^{\prime }}\text{gsi}{\tau }_{\Lambda }$ and the observation of $\Lambda$ decays from double-$\Lambda$ hypernuclei does not exclude the existence of the H. If $m_H<2m_p$, 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 ${\tau }_{A_{NN}\to A_H^{\prime }}\text{gsi}\mathrm{few}10^{29}$ yr, or short enough to be observed. An analysis of SuperK data to look for this possibility should be undertaken.

Comments: 7 pages, 3 figures