摘要: First results from the MARK III detector at SPEAR are presented based on 2.7 million J/psi decays. The eta/sub c/ is observed in three modes, J/psi yields gamma eta/sub c/, (eta/sub c/ yields rho anti rho, eta pi exp + pi exp - , ... 展开 First results from the MARK III detector at SPEAR are presented based on 2.7 million J/psi decays. The eta/sub c/ is observed in three modes, J/psi yields gamma eta/sub c/, (eta/sub c/ yields rho anti rho, eta pi exp + pi exp - , and phi phi). Using the phi phi mode, the eta/sub c/ spin-parity is determined to be 0 exp - . The known radiative J/psi decays J/psi yields gamma f(f yields pi exp + pi exp - ), gamma eta'(eta' yields gamma rho exp 0 , eta pi exp + pi exp - ), gamma f'(f' yields kappa exp + kappa exp - ), gamma theta(theta yields kappa anti kappa), and gamma iota(iota yields pi kappa anti kappa) are observed and their branching ratios found to be in agreement with previous measurements. In the J/psi yields gamma kappa exp + kappa exp - mode a new state is observed at 2.22 GeV and in the J/psi yields gamma gamma rho exp 0 and gamma eta pi exp + pi exp - modes evidence for new structures near 1.4 GeV is presented. 29 references. (ERA citation 09:011061) 收起