Cross sections and transverse single-spin asymmetries in forward neutral-pion production from proton collisions at √s = 200 GeV

Measurements of the production of forward high-energy π⁰ mesons from transversely polarized proton collisions at √s = 200 GeV are reported. The cross section is generally consistent with next-to-leading order perturbative QCD calculations. The analyzing power is small at x_F below about 0.3, and becomes positive and large at higher x_F, similar to the trend in data at √s ≤ 20 GeV. The analyzing power is in qualitative agreement with perturbative QCD model expectations. This is the first significant spin result seen for particles produced with p_T > 1 GeV=c at a polarized proton collider.