Search for the $\eta^\prime$-n bound state in the $\gamma$(d,p) reaction

A strong attractive force between a $\eta^\prime$ meson and a nucleon is theoretically suggested in the linear $\sigma$ model, which explains the partial restoration of chiral symmetry. In the same framework as the calculation of $\Lambda$(1405) which is treated as a quasibound state of $\bar{K}$N, a $\eta^\prime$-N bound state is expected with a binding energy of 6--10 MeV. The LEPS experiments at SPring-8 utilizes a photon beam up to 2.9 GeV, so that a $\eta^\prime$ meson can be photoproduced with a small recoil momentum. We searched for the $\eta^\prime$-n bound state by injecting the photon beam into a liquid deuterium target and detecting a proton at extremely forward angles with the LEPS spectrometer. The analysis status and results will be reported in this talk.