$J/\psi$ electromagnetic production associated with light hadrons at $B$ factories

Abstract

The electromagnetic productions of $J\psi$ associated with light hadrons(LH) and leptonic pairs(${\mu }^{+}{\mu }^{-}$, ${\tau }^{+}{\tau }^{-}$) at $B$ factories are studied. We find that the direct electromagnetic production cross sections of $J/\psi$($\psi (2S)$) associated with light hadrons is about $0.10(0.04)$ pb. The direct production cross sections of $J/\psi$($\psi (2S)$) associated with ${\mu }^{+}{\mu }^{-}$ is about $0.056(0.020)$ pb. If we include the contributions from $\psi (2S)$ decay, we can get the prompt cross section $\sigma [e^{+}{e}^{-}\to J/\psi +{\mu }^{+}{\mu }^{-}]=(0.068\pm 0.002)$ pb, about $(16\pm 5)$ of the Belle data $\sigma [e^{+}{e}^{-}\to J/\psi +X_{non-c\bar{c}}]=(0.43\pm 0.09\pm 0.09)$ pb, meanwhile the $e^{+}{e}^{-}\to J/\psi +{\tau }^{+}{\tau }^{-}$ process only contributes $2$. The prompt cross section $\sigma [e^{+}{e}^{-}\to J/\psi +LightHadrons]=(0.121\pm 0.005)$ pb is about $(28\pm 8)$ of the Belle data.

Comments: Suggestions and comments are wellcome.