Search for excited charmonium states in $e^+e^-$ Annihilation at $\sqrt{s}=10.6$ GeV
Kui-Yong Liu, Zhi-Guo He, Kuang-Ta Chao
TL;DR
The study applies leading-order NRQCD, including both QCD and QED contributions, to predict cross sections for a wide array of double-charmonium final states in $e^+e^-$ annihilation at $\sqrt{s}=10.6$ GeV. By detailing the formalism, wavefunction inputs, and channel-specific results across $S$-, $P$-, and $D$-wave combinations, it identifies promising modes for observing excited charmonia such as $\eta_c(3S)$, $\chi_{c0}(2P)$, and $h_c$, and discusses implications for Belle/Babar results and potential X states. The work highlights that relative production rates can be informative about the production mechanism and spectroscopy, though absolute rates require higher-order and nonperturbative corrections. It also shows that QED contributions, while generally modest, can affect specific channels and should be included in precise predictions. Overall, double-charmonium production at B factories is presented as a valuable probe of charmonium spectroscopy and QCD dynamics.
Abstract
We suggest searching for excited charmonium states in $e^+e^-$ annihilation via double charmonium production at $\sqrt{s}=10.6$ GeV with $B$ factories, based on a more complete leading order calculation including both QCD and QED contributions for various processes. In particular, for the C=+ states, the $χ_{c0}(nP)$ (n=2,3) and $η_c(mS)$ (m=3,4) may have appreciable potentials to be observed; while for the C=- states, the $η_ch_c$ production and especially the $χ_{c1}h_c$ production might provide opportunities for observing the $h_c$ with higher statistics in the future. A brief discussion for the X(3940) observed in the double charmonium production is included.
