Models of Coulomb-hadronic interference

Historically, there have been developed two approaches to calculate the effects of the interference between Coulomb and hadronic forces. Both are included in Elegent.

• The Feynman-diagram approach is best represented by the work of West Yennie ​WEST, G. B. and YENNIE, D. R., Phys. Rev. 172 (1968) 1413-1422. In this publication there are two formulae derived: (full) West-Yennie formula (denoted WY) and simplified West-Yennie formula (denoted SWY). The latter was obtained in the approximation of purely exponential hadronic amplitude with constant phase. Therefore - strictly speaking - it is not compatible with most of the phenomenological models. It is included in Elegent for reasons of comparison - the SWY formula has been used extensively (at least) until recently.

• The eikonal approach has been pursued by many authors, most recently by Kundrát and Lokajíček ​KUNDRÁT, V. and LOKAJÍČEK, M., Z. Phys. C63 (1994) 619-630. In this framework, no explicit assumption on the form of the hadronic amplitude is made. The resulting interference formula is denoted KL.

More details can be found in the journal publication linked from the home page or in Section 1.3 in ​CERN-THESIS-2011-214.

The choice of the interference model is represented by Elegent::CoulombInterference::CIMode.