Probing the twist-3 multi-gluon correlation functions by pp \to DX

Abstract

We study the single spin asymmetry (SSA) for the D-meson production $A_N^D$ in the $pp$ collision, $p^{\uparrow }p\to DX$, in the framework of the collinear factorization. Since the charm quark is mainly produced through the $c\bar{c}$-pair creation from the gluon-fusion process, this is an ideal process to probe the twist-3 triple-gluon correlation functions in the polarized nucleon. We derive the corresponding cross section formula for the contribution of the triple-gluon correlation function to $A_N^D$ in $p^{\uparrow }p\to DX$, applying the method developed for $e{p}^{\uparrow }\to eDX$ in our previous study. As in the case of $e{p}^{\uparrow }\to eDX$, our result differs from a previous study in the literature. We will also present a simple estimate of the triple-gluon correlation functions based on the preliminary data on $A_N^D$ by RHIC.

Comments: to appear in the proceedings of the 19th International Spin Physics Symposium (Spin2010), Sept.27 - Oct.2, 2010, Juelich, Germany, 5 pages, 2 figures