  We report on the first measurement of the single spin analyzing power
($A\_N$) at $\sqrt{s}=200$ GeV, obtained by the pp2pp experiment using
polarized proton beams at the Relativistic Heavy Ion Collider (RHIC). Data
points were measured in the four momentum transfer $t$ range $0.01 \leq |t|
\leq 0.03$ $\GeVcSq$. Our result is about one standard deviation above the
calculation, which uses interference between electromagnetic spin-flip
amplitude and hadronic non-flip amplitude, the source of $A\_N$. The difference
could be explained by an additional contribution of a hadronic spin-flip
amplitude to $A\_N$.
