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arXiv · hep-ph/9807324

Polarization in diffractive electroproduction of light vector mesons

D. Yu. Ivanov·R. Kirschner
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Abstract

We study in perturbative QCD the helicity ampltiudes of the process $γ^{*} p \to ρp $ at large virtualities $Q$ of the photon $γ^{*}$. We estimate all spin flip amplitudes taking into account an important effect of the scale behaviour of the gluon density. The transition of a transverse virtual photon to a longitudinal vector meson is not small at typical HERA conditions. This helicity non-conserving amplitude leads by interference to a measurable effect in the distribution of the angle between the electron scattering and the meson production planes.

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D. Yu. Ivanov, R. Kirschner. 1998-07-10. Polarization in diffractive electroproduction of light vector mesons. https://doi.org/10.1103/physrevd.58.114026

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