Masses, lifetimes and production rates of Ξ− and Ξ¯+ at LEP 1

Measurements of the Ξ− and Ξ¯+ masses, mass differences, lifetimes and lifetime differences are presented. The Ξ¯+ sample used is much larger than those used previously for such measurements. In addition, the Ξ production rates in Z→bb¯ and Z→qq¯ events are compared and the position ξ∗ of the maximum of the ξ distribution in Z→qq¯ events is measured.