Linking parton distributions to form factors and Compton scattering
M. Diehl1 - Th. Feldmann2 - R. Jakob3 - P. Kroll2
1 Deutsches Elektronen-Synchroton DESY, D-22603 Hamburg, Germany
2 Fachbereich Physik, Universität Wuppertal, D-42097 Wuppertal, Germany
3 Università di Pavia and INFN, Sezione di Pavia, I-27100 Pavia, Italy
Received: 12 November 1998 / Published online: 1 March 1999
We relate ordinary and skewed parton distributions to soft overlap contributions to elastic form factors and large angle Compton scattering, using light-cone wave functions in a Fock state expansion of the nucleon. With a simple ansatz for the wave functions of the three lowest Fock states we achieve a good description of unpolarised and polarised parton distributions at large x, and of the data for the Dirac form factor and for Compton scattering, both of which can be saturated with soft contributions only. Large angle Compton scattering appears as a good case to investigate the relative importance of soft and hard contributions in exclusive processes which are sensitive to the end point regions of the nucleon wave function.