Single spin asymmetries in polarized proton-proton, polarized antiproton-proton inclusive processes

Abstract

Single spin asymmetries in polarized proton(antiproton) + proton -> pion + X have been measured to be large. They can be understood within perturbative QCD by introducing new k_perp and spin dependences in fragmentation and/or distribution functions. We discuss first how these effects in distribution functions alone can account for existing data and predict single spin asymmetries in other processes; then we see how similar effects in fragmentation functions alone can fit the existing data; finally we devise strategies to discriminate between the two contributions

Comments: 3 pages, LaTeX, 1 ps figure, uses sprocl.sty, epsfig.sty. Talk delivered by F. Murgia at the XIII International Symposium on High Energy Spin Physics (SPIN98), September 8-12, 1998, Protvino, Russia