Abstract
Considering single-meson photo- and electroproduction off a baryon, it is shown how to restore local gauge invariance that was broken by replacing standard Feynman-type meson exchange in the channel by exchange of a Regge trajectory. This is achieved by constructing a contact current whose four-divergence cancels the gauge-invariance-violating contributions resulting from all states above the base state on the Regge trajectory. To illustrate the procedure, modifications necessary for the process are discussed in some detail. We also provide the general expression for the contact current for an arbitrary reaction.
- Received 11 September 2015
DOI:https://doi.org/10.1103/PhysRevC.92.055503
©2015 American Physical Society