Search for doubly charmed hadron at B factory

The doubly charmed hadron production at B factories is of special importance for the study of the hadron structure and the color connections before hadronization. To suppress the combination background fluctuations of the reconstructed hadron mass spectra, we suggest a three-jet event shape trigger. After these three jets are identified by their energy and angular distributions, it is found that: 1) The background process $e^+ e^- \to c\bar {c} \to h’s$inconsiderationofthefinalhadronsystem$\Lambda_c^+K^-\pi^+ +X$ are significantly suppressed. 2) For the selected events, about half of the particles, ${\mathrm{\Lambda }}_c^{+}$, $K^{-}$, ${\pi }^{+}$, which obviously can not belong to the decay products of doubly charmed hadron, can be vetoed. The relevant hadronization is investigated.