Study the exotic $\Theta^+$ in polarized photoproduction reactions
  We present an analysis of a Beam-Target double polarization asymmetry in $\gamma n\to \Theta^+ K^-$. We show that this quantity can serve as a filter for the determination of the $\Theta^+$'s spin-parity assignment near threshold. It is highly selective between $1/2^+$ and $1/2^-$ configurations due to dynamical reasons. 
Qiang Zhao