Quark-hadron duality and Q2 evolution of the GDH integral in the HERMES experiment

First results on quark-hadron duality in the spin sector from the HERMES experiment are reported in the range \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$1.2\le Q^2 \le 12$\end{document} GeV2 and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$1\le W^2 \le 4$\end{document} GeV2. A complete set of measurements of the generalised GDH integrals for the deuteron, proton and neutron is also shown in the same Q2 range and in the full W2 range.