Polarization phenomena for p)over-bar+p ->(Lambda)over-bar+Lambda in collinear kinematics as a test of polarized strangeness

Polarization effects for the process (p)over-bar + p --> (Lambda)over-bar Lambda are studied for the collinear Lambda-production. Using the triplet channel dominance hypothesis for the (p)over-bar p-annihilation, we prove t hat the longitudinal polarization transfer coefficient from the initial pro ton to final Lambda hyperon must be positive in this kinematical regime, in dependently of any model. The exact value of this coefficient, however, dep ends on the sign of the strange quark contribution to the proton spin, for relatively small momentum transfer. (C) 1999 Elsevier Science B.V. All righ ts reserved.