A study of the polarized structure function $g_1^{\rm p}(x,Q^2)$ and the polarized gluon distribution $\Delta g(x,Q^2)$ at HERA

Abstract.

We present estimates of possible data on spin-dependent asymmetries in inclusive scattering of high energy polarized electrons by high energy polarized protons at HERA with their statistical errors and discuss systematic errors. We show that these data will provide important information on the low-x behavior of the polarized structure function $g_1$, and will reduce the uncertainty in the determination of the first moment of the polarized gluon distribution $\Delta g(x,Q^2)$ obtained from the QCD analysis of $g_1$ in NLO. Furthermore, using asymmetries for di-jet events from a polarized HERA would substantially reduce the uncertainty in the shape of $\Delta g(x,Q^2)$. Use of the information on $\Delta g(x,Q^2)$ from the di-jet analysis in conjunction with the NLO QCD analysis of $g_1$ will provide an accurate determination of $\Delta g(x,Q^2)$ and its first moment.