  Ten resonances were found in the mass spectrum of pi+pi- -system from the
reaction np->nppi+pi- in np-interactions at Pn=5.20 GeV/c in the 1-m HBC of LHE
JINR by using the criterion cos(teta)[c.m.c.] p>0. Such effects were not found
in pi-pi0 - combinations from the reaction np->pppi-pi0. Therefore, it is
necessary to attribute the value of isotopic spin I = 0 to the resonances found
in the mass spectrum of the pi+pi- -system. The spin was estimated for the most
statistically provided resonances. We determine with a high degree of
confidence that J = 0 for the resonances at MR = 757 MeV/c^2 and MR = 418
MeV/c^2. Therefore, it can be affirmed that at least 3 states with quantum
numbers of sigma0-meson 0+(0++) have been found at masses of 418, 511 and 757
MeV/c^2. The fact low-mass sigma0-mesons are glueballs is one of the possible
interpretations. The comparison with the data of other papers has also been
made. The investigation has been performed at the Veksler and Baldin Laboratory
of High Energies,JINR.
