Nucleon Form Factors in the Space- and Timelike Regions

Abstract

Dispersion relations provide a powerful tool to describe the electromagnetic form factors of the nucleon both in the spacelike and timelike regions with constraints from unitarity and perturbative QCD. We give a brief introduction into dispersion theory for nucleon form factors and present results from a recent form factor analysis. Particular emphasis is given to the form factors in the timelike region. Furthermore, some recent results for the spacelike form factors at low momentum transfer from a ChPT calculation by Kubis and Meissner are discussed.

Comments: Invited talk (W08) at Workshop on "e+e- Physics at Intermediate Energies", SLAC, April 30 - May 2, 2001, Latex, 6 pages, 4 figures, uses JAC2000.cls