The processes , , and are measured using an data sample collected with the Belle detector at the KEKB asymmetric-energy collider. Production of vector meson pairs is clearly observed and their cross sections are measured for masses that range from threshold to 4.0 GeV. In addition to signals from well established spin-zero and spin-two charmonium states, there are resonant structures below charmonium threshold, which have not been previously observed. We report a spin-parity analysis for the new structures and determine the products of the , , and two-photon decay widths and branching fractions to , , and .
- Received 25 February 2012
© 2012 American Physical Society