Photoproduction of hidden-charm states in the $\gamma p\to {\bar{D}}^{\ast 0}{\Lambda }_c^{+}$ reaction near threshold

Abstract

We report on a theoretical study of the hidden charm $N_{c\bar{c}}^{\ast }$ states in the $\gamma p\to {\bar{D}}^{\ast 0}{\Lambda }_c^{+}$ reaction near threshold within an effective Lagrangian approach. In addition to the contributions from the $s$-channel nucleon pole, the $t$-channel $D^0$ exchange, the $u$-channel ${\Lambda }_c^{+}$ exchange and the contact term, we study the contributions from the $N_{c\bar{c}}^{\ast }$ states with spin-parity $J^P=1/2^{-}$ and $3/2^{-}$. The total and differential cross sections of the $\gamma p\to {\bar{D}}^{\ast 0}Lambd{a}_c^{+}$ reaction are predicted. It is found that the contributions of these $N_{c\bar{c}}^{\ast }$ states give clear peak structures in the total cross sections. Thus, this reaction is another new platform to study the hidden-charm states. It is expected that our model calculation may be tested by the future experiments.

Comments: 8 pages, 5 figures. Accepted for publication in Chinese Physics C