Nonperturbative versus perturbative effects in generalized parton   distributions
  Generalized parton distributions (GPDs) are studied at the hadronic (nonperturbative) scale within different assumptions based on a relativistic constituent quark model. In particular, by means of a meson-cloud model we investigate the role of nonperturbative antiquark degrees of freedom and the valence quark contribution. A QCD evolution of the obtained GPDs is used to add perturbative effects and to investigate the GPDs' sensitivity to the nonperturbative ingredients of the calculation at larger (experimental) scale. 
B. Pasquini (1 and 2), M. Traini (2 and 3), S. Boffi (1) ((1) Pavia   University and INFN, Pavia, (2) ECT*, Trento, (3) Tren...