First photo-pion double polarization experiments using polarized (H)over-right-arrow(D)over-right-arrow at LEGS

We report preliminary results of pi photo-production using polarized gamma beams and a polarized HD target. Four observables can be extracted simultaneously from the data, the cross section, the beam asymmetry Sigma, and the double-polarization observables G and E. The latter determines the GDH sum rule integral.