Abstract
We have searched for the two-photon production of the , , and charmonium states at the SLAC collider PEP in the channels , , , and . We identify four candidates in the channel on a negligible background; the one event among them implies a 95%-confidence-level (C.L.) lower limit for of 1.7 keV. In the other channels we find no evidence for any of the three states. We establish 95%-C.L. upper limits keV, keV, and keV. From all channels combined, we obtain the value keV.
- Received 30 November 1987
DOI:https://doi.org/10.1103/PhysRevLett.60.2355
©1988 American Physical Society