${\mathrm{\Lambda }}_c^{+}(2940)$ photoproduction off the neutron

By assuming that the ${\mathrm{\Lambda }}_c^{\ast }(2940)$ is a $p{D}^{\ast 0}$ molecular state with spin-parity $J^P={\frac{1}{2}}^{+}$ and $J^P={\frac{1}{2}}^{-}$, the photoproduction of charmed $\Lambda _{c}^{\ast }(2940)$baryoninthe$\gamma n\rightarrow D^{-}\Lambda _{c}^{\ast }(2940)^{+}$ process is investigated with an effective Lagrangian approach. It is found that the contributions from $t$-channel with $D^{\ast }$ exchange are dominant, while the $s$-channel with nucleon pole exchange give a sizeable contribution around the threshold. The contributions from the $u$-channel and contact term are very small. The total cross section of the $\gamma n\rightarrow D^{-}\Lambda _{c}^{\ast }(2940)^{+}$ reaction is estimated, which indicate it is feasible to searching for the charmed $\Lambda _{c}^{\ast }(2940)$ baryon at the COMPASS experiment.