Amplitudes ratios in ${\rho }^0$ leptoproductions and GPDs

Abstract

We investigate exclusive leptoproduction of ${\rho }^0$ meson. These reactions were analyzed within the factorizing handbag approach. In our model good agreement of observables for light meson production with experimental data in a wide energy range was found. Using the model results we calculate the ratio of different helicity amplitudes for a transversely polarized proton target to the leading twist longitudinal amplitude. Our results are close to the amplitude ratios measured by HERMES.

Comments: 6 pages, 5 figures, International Baldin Seminar Relativistic Nuclear Physics and Quantum Chromodynamics, Dubna, September, 2016