The phase of the sigma -> pi-pi amplitude in J/Psi -> omega-pi-pi
  The phase variation of the sigma -> pi-pi amplitude is accurately determined as a function of mass from BES II data for J/Psi -> omega-pi-pi. The determination arises from interference with the strong b1(1235)-pi amplitude. The observed phase variation agrees within errors with that in pi-pi elastic scattering. 
D.V. Bugg (Queen Mary, University of London)