Li, G (reprint author), Inst High Energy Phys, Beijing 100049, Peoples R China.
Using 14M psi(2S) events accumulated by BESII at the BEPC, a covariant helicity amplitude analysis is performed for psi(2S) -> pi(+)pi(-)J/psi, J/psi -> mu(+)mu(-). The pi(+)pi(-) mass spectrum, distinctly different from phase space, suggests or production in this process. Two different theoretical schemes are used in the global fit to the data. The results are consistent with the existence of the sigma. The sigma pole position is determined to be (552(-106)(+84) -i(232(-72)(+81)) MeV/c(2). (c) 2006 Elsevier B.V. All rights reserved.