On a possible observation of "dihelion" in dissociation of relativistic ${}^9$C nuclei

Nuclear track emulsion is exposed to 1.2 A ${}^9$C GeV nuclei. Pairs of 2${}^3$He nuclei having unusually narrow opening angles are observed in channel ${}^9$C $\to$ 3${}^3$He pointing to the possible 2${}^3$He resonance near the production threshold.