Cross Sections and Transverse Single-Spin Asymmetries in Forward Neutral-Pion Production from Proton Collisions ats=200 GeV

Measurements of the production of forward high-energy ${\ensuremath{\pi}}^{0}$ mesons from transversely polarized proton collisions at $\sqrt{s}=200\text{ }\text{ }\mathrm{GeV}$ 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 $\sqrt{s}\ensuremath{\le}20\text{ }\text{ }\mathrm{GeV}$. The analyzing power is in qualitative agreement with perturbative QCD model expectations. This is the first significant spin result seen for particles produced with ${p}_{T}>1\text{ }\text{ }\mathrm{GeV}/c$ at a polarized proton collider.