SIGNATURE OF THE TRIANGLE SINGULARITY IN THE REACTION E+E--]PI+PI-PI-0

The singularity caused by the decay kinematics in the vertices of the triangle diagram is shown to imply the distortion of the patterns of rhoomega interference in the pi+pi- mass spectrum of the reaction e+e- --> rhopi + omegapi --> pi+pi-pi0 at energies in the range 0.95 GeV less-than-or-equal-to square-root s less-than-or-equal-to 1.4 GeV. In the total cross section the singularity manifests itself as a measurable decrease of the cross section magnitude at energies in between omega and phi peaks. The studies of the effect at e+e-colliders with a luminosity of L = 10(31) cm-2 s-1 or higher could be of great interest as a tool for testing the self-consistency of calculations going beyond the tree approximation and as a possibility to obtain additional information on the mechanisms of the OZI rule and G parity breakings.