Some aspects of ${\Theta }^{+}$ parity determination in the reaction $\gamma N\to {\Theta }^{+}\bar{K}\to NK\bar{K}$

Abstract

We analyze the problem of how to determine the parity of the ${\Theta }^{+}$ pentaquark in the reaction $\gamma N\to K\Theta \to NK\bar{K}$, where $N=n,p$. Our model calculations indicate that the contribution of the non-resonant background of the reaction $\gamma N\to NK\bar{K}$ cannot be neglected, and that suggestions to determine the parity based solely on the initial-stage process $\gamma N\to K\Theta$ cannot be implemented cleanly. We discuss the various mechanisms that contribute to the background, and we identify some spin observables which are sensitive.

Comments: 39 pages, 25 figures