Speaker
Description
The investigation of hypernuclei with strangeness $-2$ is one of the hot topics in hypernuclear physics, and the advent of an intense kaon beam at J-PARC has enabled us to explore them in detail. We have proposed a new experiment to produce probably the lightest double-$\Lambda$ hypernucleus, ${}^{\ \ \ \ 5}_{\Lambda\Lambda}\mathrm{H}$. A substantial fraction of a $\Xi$-hypernucleus, ${}^{\ 7}_{\Xi}\mathrm{H}$, which can be produced in the ${}^7\mathrm{Li}(K^-,K^+)$ reaction, is expected to decay into ${}^{\ \ \ \ 5}_{\Lambda\Lambda}\mathrm{H}+2n$. The mass of ${}^{\ \ \ \ 5}_{\Lambda\Lambda}\mathrm{H}$ will be determined by ``decay pion spectroscopy'', which was successfully applied for a single $\Lambda$ hypernucleus at MAMI.
In this contribution, we will review the current situation of the strangeness $-2$ sector in hypernuclear physics and outline the concept of the proposed experiment.
