Weighted azimuthal asymmetries in a diquark spectator model A. Bacchetta, M. Radici, F. Conti and M. Guagnelli Eur. Phys. J. A, 45 3 (2010) 373-388 Published online: 05 August 2010 DOI: 10.1140/epja/i2010-11016-y