Single-Transverse-Spin Asymmetries of Identified Charged Hadrons in Polarized pp Collisions at s=62.4 GeV

The first measurements of ${x}_{F}$-dependent single-spin asymmetries of identified charged hadrons, ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, ${K}^{\ifmmode\pm\else\textpm\fi{}}$, and protons, from transversely polarized proton-proton collisions at 62.4 GeV at RHIC are presented. Large asymmetries are seen in the pion and kaon channels. The asymmetries in inclusive ${\ensuremath{\pi}}^{+}$ production, ${A}_{N}({\ensuremath{\pi}}^{+})$, increase with ${x}_{F}$ from 0 to $\ensuremath{\sim}0.25$ and ${A}_{N}({\ensuremath{\pi}}^{\ensuremath{-}})$ decrease from 0 to $\ensuremath{\sim}\ensuremath{-}0.4$. Observed asymmetries for ${K}^{\ensuremath{-}}$ unexpectedly show positive values similar to those for ${K}^{+}$, increasing with ${x}_{F}$, whereas proton asymmetries are consistent with zero over the measured kinematic range. Comparisons of the data with predictions of QCD-based models are presented.