Abstract
We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions and , and the electric and magnetic generalized polarizabilities (GPs) and at momentum transfer and . The electric GP shows a strong falloff with , and its global behavior does not follow a simple dipole form. The magnetic GP shows a rise and then a falloff; this can be interpreted as the dominance of a long-distance diamagnetic pion cloud at low , compensated at higher by a paramagnetic contribution from intermediate states.
- Received 23 December 2003
DOI:https://doi.org/10.1103/PhysRevLett.93.122001
©2004 American Physical Society