New measurement of the production polarization and magnetic moment of theΞ−hyperon

We have measured the production polarization and magnetic moment of a sample of 89{times}10{sup 3} {Xi}{sup {minus}} hyperons produced in the inclusive reaction {ital p}(400 GeV/{ital c})+Cu{r arrow}{Xi}{sup {minus}}+X. The weighted average of the polarization is {minus}0.070{plus minus}0.008{plus minus}0.010 at a {ital p}{sub {ital t}} of 0.63 GeV/{ital c}. The {Xi}{sup {minus}}'s magnetic moment yields the value {mu}{sub {Xi}}={minus}0.661{plus minus}0.036{plus minus}0.036 nuclear magnetons. The first error is statistical, the second systematic.