Measurement of the Transverse Single-Spin Asymmetry for Mid-rapidity Production of Neutral Pions in Polarized p+p Collisions at 200 GeV Center-of-Mass Energy

The transverse single-spin asymmetry, A_N, for neutral pion production at x_F ≈ 0.0 for 1 < p_T < 5 GeV/c from polarized proton-proton interactions at √s = 200 GeV has been presented. The measurement is in a kinematic regime where the theoretical framework of perturbative QCD has been demonstrated to describe the polarization-averaged cross sections for neutral pions and charged hadrons well for p_T > 1.5 GeV/c. A pQCD framework is expected to be applicable in the interpretation of the polarized results down to similar transverse momentum values.