Résumé du preprint Irfu-11-102

Irfu-11-102
Precise measurement of Beam Spin Asymmetries in Semi-Inclusive pi0 production
M. Aghasyan et al (J. Ball, M. Garçon, B. Moreno, H. Moutarde, S. procureur, F. Sabatié)
We present studies of single-spin asymmetries for neutral pion electroproduction in semi-inclusive deep-inelastic scattering of 5.776 GeV polarized electrons from an unpolarized hydrogen target, using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. A substantial sin(phi_h) amplitude has been measured in the distribution of the cross section asymmetry as a function of the azimuthal angle phi_h of the produced neutral pion. The dependence of this amplitude on Bjorken x and on the pion transverse momentum is extracted with significantly higher precision than previous data and is compared to model calculations.