Single Transverse-Spin Asymmetry in $p{p}^{\uparrow }\to \pi X$ and $e{p}^{\uparrow }\to \pi X$

Abstract

Cross section formulas for the single spin asymmetry in $p^{\uparrow }p\to \pi ({\ell }_T)X$ and $e{p}^{\uparrow }\to \pi ({\ell }_T)X$ are derived and its characteristic features are discussed.

Comments: 5 pages in LaTex. Talk presented at SPIN'02 held at BNL from Sep. 9 to 14, 2002. Typos corrected