Abstract
We study the processes , and , where the photon is radiated from the initial state. About 34 600, 4400 and 2300 fully reconstructed events, respectively, are selected from of BABAR data. The invariant mass of the hadronic final state defines the effective center-of-mass energy, so that the data can be compared with direct measurements of the reaction; no direct measurements exist for the or reactions. Studying the structure of these events, we find contributions from a number of intermediate states, and we extract their cross sections where possible. In particular, we isolate the contribution from and study its structure near threshold. In the charmonium region, we observe the in all three final states and several intermediate states, as well as the in some modes, and measure the corresponding branching fractions. We see no signal for the and obtain an upper limit of at 90% C.L.
35 More- Received 1 May 2007
DOI:https://doi.org/10.1103/PhysRevD.76.012008
©2007 American Physical Society