Spin Transfer in Inclusive {Lambda}{sup 0} Production by Transversely Polarized Protons at 200GeV/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{sub N} was found in inclusive {Lambda}{sup 0} production with a 200GeV/c transversely polarized proton beam. The depolarization D{sub NN} in p{up_arrow}+p{r_arrow}{Lambda}{sup 0}+X has been measured with the same beam over a wide x{sub F} range and at moderate p{sub T} . D{sub NN} reaches positive values of about 30{percent} at high x{sub F} and p{sub T}{approximately}1.0GeV/c . This result shows a sizable spin transfer from the incident polarized proton to the outgoing {Lambda}{sup 0} . {copyright} {ital 1997} {ital The American Physical Society}