Original scientific paper

Vertex corrections in vector-meson photoproduction

M. Martinis ; "Ruđer Bošković" Institute, Zagreb
J. Trampetić ; "Ruđer Bošković" Institute, Zagreb
N. Bilić ; "Ruđer Bošković" Institute, Zagreb

Abstract

The size of the one-pion-exchange (OPE) contribution to yp→V°p processes is analysed. Effects of virtuality of the π meson are taken into account in the form of vertex corrections. A suitable parametrization of the Vπy form factor Fv (t) is obtained under the assumption of equality between radiative decay widths of V when the pion is on and slightly off the mass shell. For the πNN form factor K(t), a simple ansatz is used according to which K(t) is given by the sum (not necessarily infinite) of poles with a linearly rising mass trajectory. Detailed comparison between several parametrizations of K(t) found in the literature leads to a three-parameter expression for K(t). In special cases, K(t) can be reduced to the form factors considered by Hamilton, Pilkuhn and Wolf. Some other behaviours of K(t) (dipole or Veneziano-like) are also considered. Effects of the different parametrizations of K(t) have on the OPE contribution to the differential cross section for the yp→ωp process at large t are illustrated.

Keywords

Hrčak ID:

327973

URI

https://hrcak.srce.hr/327973

Publication date:

3.4.1978.

Article data in other languages: croatian

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