A Brief Review of the Study of Unstable States in the Dissociation of Relativistic Nuclei

The article presents a review of the results of studies of the unstable states in the relativistic dissociation of nuclei ¹⁰B, ^11,12C, ¹⁶O, ²²Ne, ²⁸Si, ⁸⁴Kr, and ¹⁹⁷Au in the energy range from hundreds of MeV/nucleon to several tens of GeV/nucleon using the nuclear track method. A systematic study of the fragmentation of incident nuclei with multiple production of the lightest fragments of He and H made it possible to study the dynamics of the manifestation of unstable nuclear states of ⁸Be, the Hoyle state, and the 4α-particle state of the ¹⁶O nucleus above the threshold in the relativistic dissociation of nuclei thanks to precision measurements of fragment outgoing angles. It is shown that, to reconstruct the relativistic decays of unstable nuclei in a nuclear photographic emulsion, it is sufficient to determine the invariant mass of the system of He and H fragments in the approximation of conservation of momentum per nucleon of the parent nucleus. This approach makes it possible to search for more complex nuclear states. An indication was obtained of an increase in the probability of detecting ⁸Be with an increase in the number of relativistic α particles in the event.