Measurement Of Spin-Transfer Observables In (P)Over-Bar-P ->(Lambda)Over-Bar-Lambda At 1.637 Gev/C

Spin-transfer observables for (p) over barp --> (Lambda) over bar Lambda have been measured using a transversely polarized frozen-spin target and a beam momentum of 1.637 GeV/c. Current models of the reaction near threshold are in good agreement with existing measurements performed with unpolarized particles in the initial state but produce conflicting predictions for the spin-transfer observables D(nn) and K(nn) (the normal-to-normal depolarization and polarization transfer), which are measurable only with polarized target or beam. Measurements of D(nn) and K(nn) presented here are found to be in disagreement with predictions from these models.