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Cross Sections and Transverse Single-Spin Asymmetries in Forward Neutral Pion Production from Proton Collisions at sqrt(s) = 200 GeV

Measurements of the production of forward high-energy pi0 mesons from transversely polarized proton collisions at \sqrt{; ; 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 \sqrt{; ; 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.

differential cross section; energy dependence; spin; asymmetry

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