Spin transfer in inclusive Lambda(0) production by transversely polarized protons at 200 GeV/c

Surprisingly large polarizations in hyperon production by unpolarized protons have been known for a long time. The spin dynamics of the production process can be further investigated with polarized beams. Recently, a negative asymmetry A(N) was found in inclusive Lambda(0) production with a 200 GeV/c transversely polarized proton beam. The depolarization D-NN in p up arrow + p --> Lambda(0) + X has been measured with the same beam over a wide x(F) range and at moderate p(tau). D-NN reaches positive values of about 30% at high x(F) and p(T) similar to 1.0 Ge V/c. This result shows a sizable spin transfer from the incident polarized proton to the outgoing Lambda(0).