Eur. Phys. J. A (2006) 29: 209-220
https://doi.org/10.1140/epja/i2006-10070-4

Hadron Physics

φ-meson photoproduction from nuclei

¹ Helmholtz-Institut für Strahlen- und Kernphysik (Theorie), Universität Bonn, Nußallee 14-16, D-53115, Bonn, Germany
² Institut für Kernphysik (Theorie), Forschungszentrum Jülich, D-52425, Jülich, Germany
³ Jefferson Lab, 12000 Jefferson Ave., 23606, Newport News, VA, USA

^* e-mail: a.sibirtsev@fz-juelich.de

Received: 22 June 2006
Accepted: 10 July 2006
Published online: 25 July 2006

Abstract

We study coherent and incoherent φ-meson photoproduction from nuclei. The available data are analyzed in terms of single- and coupled-channel photoproduction. It is found that the data on coherent photoproduction can be well reproduced within a single-channel optical model and show only little room for ω-φ mixing. These data indicate a normal distortion of the φ-meson in nuclei, which is compatible with the results obtained through the vector meson dominance model. The data on incoherent φ-meson photoproduction show an anomalous A-dependence resulting in a very strong φ-meson distortion. These data can be explained by a coupled-channel effect through the dominant contribution from the ω↦φ or the π↦φ transition or, more speculative, through the excitation of a cryptoexotic B _φ-baryon.