Narrow resonances in the system of two π--mesons

The study of the production of exotic 4-quark resonances with isotopic spin I=2 in the π-π--systems from the reaction np→ppπ+π-π- was carried out using the data obtained in the irradiation of 1m H2 bubble chambers of LHE, JINR by neutrons at the momentum Pn=5.20±0.13 GeV/c. A number of enhancements was found at the masses of 0.330; 0.354; 0.397; 0.447; 0.510; 0.569; 0.650; 0.736; 0.822, and 0.920 GeV/c2. Experimental widths of resonances are comparable with the resolution that is linearly increasing from 1.4 to 15.0 MeV/c2 (σres) under alteration of masses from the sum of masses of pions to ≅1 GeV/c2. An attempt was made to determine the spins of resonances. For the resonances at the mass of 0.397 GeV/c2, the most probable value of spin was proved to be equal to J≥6. 3 refs., 3 figs. 1 tab