[Zhang, Z. X.
; Zheng, H. Q.] Peking Univ, Dept Phys, Beijing 100871, Peoples R China
; [Zhang, Z. X.
; Shen, X. Y.
; Wu, N.] Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
; [Sanz-Cillero, J. J.] Univ Autonoma Barcelona, IFAE, E-08193 Barcelona, Spain
; [Xiao, L. Y.] Olivet Univ, Olivet Inst Technol, San Francisco, CA 94103 USA
We propose a measurement of the elastic pi pi scattering phase-shift difference delta(0)(0)-delta(2)(0) through the Psi(')-> J/Psi pi(+)pi(-) process in the future high statistics BES-III experiment. The decay amplitude is constructed with seven Lorentz invariant form factors and is compared with their theoretical estimation. Based on a Monte Carlo study, it is found that the phase-shift difference can be indeed recovered and, hence, it is expected to be measured in the energy region between 350 and 550 MeV at future BES-III.