harder to make into a beam than singly strange hadrons. However, an experiment at J-PARC begun in 2020 will compile data on Ξ and ΛΛ hypernuclei using a similar, non-beam setup where scattered Ξ− baryons rain onto an emulsion target. Heavy-ion collisions Similar species Kaonic nuclei The K– meson can orbit a nucleus in an exotic atom, such as in kaonic hydrogen. Although the K–-proton strong interaction in kaonic hydrogen is repulsive, the K––nucleus interaction is attractive for larger systems, so this meson can enter a strongly bound state closely related to a hypernucleus; in particular, the K––proton–proton system is experimentally known and more tightly bound than a normal nucleus. Charmed hypernuclei Nuclei containing a charm quark have been predicted theoretically since 1977, and are described as charmed hypernuclei despite the possible absence of strange quarks. In particular, the lightest charmed baryons, the Λc and Σc baryons, are predicted to exist in bound states in charmed hypernuclei, and could be created in processes analogous to those used to make hypernuclei. The depth of the Λc potential in nuclear matter is predicted to be 58 MeV, but unlike Λ hypernuclei, larger hypernuclei containing the positively charged Λc would be less stable than the corresponding Λ hypernuclei due to Coulomb repulsion. The mass difference between the Λc and the is too large for appreciable mixing of these baryons to occur in hypernuclei. Weak decays of charmed hypernuclei have strong relativistic corrections compared to those in ordinary hypernuclei, as the energy released in the decay process is comparable to the mass of the Λ baryon. See also Strangelet, a hypothetical form of matter that also contains strange quarks Notes References Exotic matter Nuclear physics Strange quark