Search for the $\Theta^+$ in the $\gamma d \to K^+ K^- p(n)$ reaction

A signature indicating the existence of the S=+1 pentaquark state ($\Theta^+$) has been reported in more than ten experiments in a variety of reactions. On the other hand, there are a number of non-observations, mainly from the $e^+e^-$ collider experiments and other experiments at high-energy facilities. The main criticism for the existence of the $\Theta^+$ is the low statistical significance. None of the positive results show a high significance with sufficient statistics. A new experiment to search for the $\Theta^+$ in the photon-induced production on a deuteron has been pursued using the CLAS detector and the tagged-photon facility at Jefferson Laboratory. The integrated luminosity of the new data is about 10 times greater than the previously published CLAS data on a deuterium target. In this talk, an experimental overview and current analysis results for the $\gamma+d \rightarrow K^+K^-p (n)$ reaction will be presented.