A measurement of the single-spin asymmetry AN in p↑ + p→π0 + X at 200 GeV with xF = 0 shows a transition in the production process from a "low-xT" regime with AN = 0, through an intermediate region of negative asymmetry, to a "high-xT" regime with AN > 0.3. This transition occurs at xT ≈ 0.4 and is consistent with xT-scaling of AN in pion production using polarized beams or targets from √-s=5.2 to 19.4 GeV. Results for AN in η production by polarized protons and in π0 production by polarized antiprotons are also presented.
ASJC Scopus subject areas
- Nuclear and High Energy Physics