Search for Resonances in the Mass Spectrum of Two-Photon Events Produced in π+A-Interactions in the Hyperon-M Experiment at the U-70 Accelerator Complex

Studies at the Nuclotron in JINR indicate the presence of a previously unknown resonance-like structure in the two-photon mass spectrum in the region of 300–400 MeV/ c 2 , observed in nucleus–nucleus interactions. The goal of this work is to search for such structures in the two-photon mass spectrum in meson–nuclear interactions at a momentum of 7 GeV/ c at the Hyperon-M experiment of the U-70 accelerator complex. An upper limit has been established on the ratio of the cross section for the formation of unknown resonance structures to the cross section for the production of -meson at the 95% confidence level.