Physics of Particles and Nuclei, 2022, Vol. 53, No. 2, pp. 456–460

The first results on analysis of determination of the contribution of decays of unstable and nuclei and the Hoyle -state into the dissociation of are presented. Layers of nuclear track emulsion longitudinally exposed to GeV/с nuclei at the JINR Nuclotron are used as the research material. Under the assumption that and fragments preserve momentum per nucleon of the primary nucleus, these unstable states are identified by the minimum invariant mass calculated using fragment emission angles.