Comparison of spin asymmetries and cross sections in pi° production by 200 GeV polarized antiprotons and protons

The single-spin asymmetry A(N) (antiproton_proton) for inclusive pi-0 production at 0.5 < p(t) < 2 GeV/c by 200 GeV transversely-polarized antiprotons on protons has been measured at Fermilab over a wide range of X(F). We observed that A(N) (antiproton_proton) has the same sign, a similar X(F) dependence, and about half the magnitude as A(N) (pp) for pi-0 production by protons. We also present the ratio of the spin-averaged cross sections for pi-0 production by antiprotons and by protons.