Diphoton and dipion productions at the Nuclotron/NICA

. Along with and mesons, a resonance structure in the invariant-mass spectrum of two photons at MeV is observed in the reaction at momentum 2.75GeV/ c per nucleon. Estimates of its width and production cross section are MeV and μb, respectively. The collected statistics amount to events of triggered interactions of a total number of interactions. This resonance structure is not observed in the channel in collisions at the beam momentum 5.5GeV/ c . The result obtained in the reaction is confirmed by the second experiment carried out on the deuteron beam at momentum 3.83GeV/ c per nucleon with a copper target: MeV, MeV and μb. Some results on the observation of the resonance in the invariant-mass spectra of two mesons are presented: the data obtained in the reaction is confirmed by the results for the and reactions; a preliminary estimate of the ratio is . Further studies of this resonance is assumed at the Nuclotron/NICA at higher setup acceptance, which will allow to elucidate the nature of this resonance by determination of the differential cross sections at different beam energies in the range 1-6GeV/n and the mechanism of its formation.