Constraint on \Delta g(x) from \pi^0 production at RHIC

Abstract

We determine the polarized gluon distribution \Delta g(x) by a global analysis using current DIS and \pi^0 asymmetry data. The \pi^0 data from RHIC-Spin experiments provide a strong constraint on \Delta g(x), so that its uncertainty is reduced. However, a sign problem appears in the analysis using \pi^0 data, which means that positive and negative distributions are allowed for \Delta g(x). These two types of solutions are discussed.

Comments: 4 pages, 4 eps figures, to be published in AIP proceedings of the 17th International Spin Physics Symposium (SPIN2006), Oct. 2-7, 2006, Kyoto, Japan