Model-independent determination of the parity of $\Xi$ hyperons

Abstract

Based on reflection symmetry in the reaction plane, it is shown that measuring the transverse spin-transfer coefficient $K_{yy}$ in the $\bar{K}N\to K\Xi$ reaction directly determines the parity of the produced cascade hyperon in a model-independent way as ${\pi }_{\Xi }=K_{yy}$, where ${\pi }_{\Xi }=\pm 1$ is the parity. This result based on Bohr's theorem provides a completely general, universal relationship that applies to the entire hyperon spectrum. A similar expression is obtained for the photoreaction $\gamma N\to KK\Xi$ by measuring both the double-polarization observable $K_{yy}$ and the photon-beam asymmetry $\Sigma$. Regarding the feasibility of such experiments, it is pointed out that the self-analyzing property of the $\Xi$'s can be invoked, thus requiring only a polarized nucleon target.

Comments: 4 pages, REVTeX, to be published in Phys. Rev. C