Progress in hyperon production at Lear

The studies of hyperon reactions with antiprotons close to threshold offer an excellent opportunity to examine the dynamics of strangeness creation. At the LEAR facility at CERN, the PS185 Collaboration has initiated a set of measurements of the process antipp → antiΛ Λ between the reaction threshold and excess energies of 170 MeV. Above an antiproton momentum of 1.65 GeV/c the reaction antipp → antiΛ Σ0 + c.c. offers the possibility of studying the isospin structure in strangeness exchange. For the charged antiΣ Σ channels, no data exist in the accessible range of LEAR, which corresponds to the region close to threshold. A dedicated run of experiment PS185 to measure the reactions antipp → antiΣ+Σ+ and antipp → antiΣ- Σ- is in preparation