Radiative decays of theψ(3684)into high-mass states

Abstract

Results of studies of radiative decays of the $\psi \mathrm{}\left(3684\right)\mathrm{}$ using the SLAC-LBL magnetic detector at the electron storage ring SPEAR are presented. There are three high-mass states produced in $\psi \mathrm{}\left(3684\right)\mathrm{}$ radiative decays, with masses of 3414±3, 3503±4, and 3551±4 MeV where the errors given do not include an overall mass-scale uncertainty of ±4 MeV. There is some evidence for a fourth such state at either 3455 or 3340 MeV. The branching ratio for $\psi \mathrm{}\left(3684\right)\mathrm{}$ radiative decay into the state at 3414 MeV is found to be (7.5 ± 2.6)%. The decay modes of these states into hadrons and into $\gamma \psi \mathrm{}\left(3095\right)\mathrm{}$ are studied, yielding information about the branching ratios, spins, and parities of the states. The results are interpreted in the charmonium picture of the high-mass states.