FIZIKA B 8 (1999) 2, 375-382

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VECTOR MESONS r r' AND r" DIFFRACTIVELY PHOTO- AND LEPTOPRODUCED

G. KULZINGER

Institut für Theoretische Physik der Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg, Germany
E-mail:
G.Kulzinger@thphys.uni-heidelberg.de

Received 14 January 1999; Accepted 12 July 1999

In the framework of non-perturbative QCD, we calculate high-energy diffractive production of vector mesons r r' and r" by real and virtual photons on a nucleon. The initial photon dissociates into a qq -dipole and transforms into a vector meson by scattering off the nucleon which, for simplicity, is represented as quark-diquark. The relevant dipole-dipole scattering amplitude is provided by the non-perturbative model of the stochastic QCD vacuum. The wave functions result from considerations in the frame of light-front dynamics; the physical r r' and r"-mesons are assumed to be mixed states of an active 2S-excitation and some residual rest (2D- and/or hybrid state). We obtain good agreement with the experimental data and get an understanding of the markedly different p+p--mass spectra for photoproduction and e+e--annihilation.

PACS numbers: 12.38.-t, 13.60.Le
UDC 539.126

Keywords: non-perturbative QCD, diffraction, photoproduction, photon wave function, r-meson, excited vector mesons, hybrid

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