Eur. Phys. J. A (2005) 24: 419-430
https://doi.org/10.1140/epja/i2005-10030-6

Original Article

Nucleon electromagnetic form factors and polarization observables in space-like and time-like regions

DAPNIA/SPhN, CEA/Saclay, 91191, Gif-sur-Yvette Cedex, France

^* e-mail: etomasi@cea.fr

Received: 23 March 2005
Accepted: 8 April 2005
Published online: 27 May 2005

Abstract

We perform a global analysis of the experimental data of the electromagnetic nucleon form factors, in space-like and time-like regions. We give the expressions of the observables in annihilation processes, such as p + ¯↦ℓ⁺ + ℓ^-, ℓ = e or μ, in terms of form factors. We discuss some of the phenomenological models proposed in the literature for the space-like region, and consider their analytical continuation to the time-like region. After determining the parameters through a fit on the available data, we give predictions for the observables which will be experimentally accessible with large statistics, polarized annihilation reactions