Polarization of ${\Xi }^{-}$ and ${\Omega }^{-}$ hyperons produced from neutral beams

We have studied the polarization of ${\Xi }^{-}$ and ${\Omega }^{-}$ hyperons produced by high energy neutral particle beams. An unpolarized neutral beam striking a target at ±1.8 mrad produced $1.4\times {10}^7{\Xi }^{-}\text{'}\mathrm{s}$ with an average momentum of 395 GeV/c which were unpolarized, within a sensitivity limit of 0.007, and 2.2 × ${10}^5$ ${\Omega }^{-}\text{'}\mathrm{s}$ with a polarization of +0.042±0.007 at an average momentum of 374 GeV/c. A polarized neutral beam striking a target at 0.0 mrad produced $7.1\times {10}^5{\Xi }^{-}\text{'}\mathrm{s}$ which had a polarization of -0.118±0.004 at an average momentum of 393 GeV/c and 1.8 × ${10}^4$ ${\Omega }^{-}\text{'}\mathrm{s}$ with a polarization of -0.069±0.023 at an average momentum of 394 GeV/c. The polarized neutral beam measurement is in good agreement with a previous measurement. The unpolarized neutral beam results are not understood in the context of the current models of hyperon polarization.