Helicity Amplitudes and Sum Rules for Real and Virtual Photons
arXiv:nucl-th/0012045 · doi:10.1142/9789812811448_0006
Abstract
Results of the recently developed unitary isobar model (MAID) are presented for helicity amplitudes, spin asymmetries, structure functions and relevant sum rules for real and virtual photons in the resonance region. Our evaluation of the energy-weighted integrals is in good agreement for the proton but shows big discrepancies for the neutron.
arXiv comment10 pages LaTeX including 3 figures, Talk given at the GDH 2000 Conference, Mainz, June 14-17, 2000; to be published in World Scientific