Possibility of determinig the parity of the pentaquark $\Theta^+$ from photoproduction near threshold

Abstract

We discuss the possibility of determining the parity of the $\Theta^+$ baryon from photoproduction $\gamma N\to K\Theta^+$ process near threshold. We utilize the conservation laws of parity and angular momentum for the analysis of angular distributions and spin observables near threshold. Since the discussion is in essence a partial wave analysis of the production mechanism the result should be less dependent on the model parameters. Our analysis shows that the angular distribution and photon polarization asymmetry for the process of neutron target are sensitive to the parity of the $\Theta^+$, but not for the case of proton target. In the case of proton target, the polarization asymmetries of target and recoiled $\Theta^+$ are preferred for parity determination.