Dual parametrization of the proton generalized parton distribution functionsHandE, and description of the deeply virtual Compton scattering cross sections and asymmetries

We develop the minimal model of a new leading order parametrization of generalized parton distributions (GPDs) introduced by Polyakov and Shuvaev. The model for GPDs $H$ and $E$ is formulated in terms of the forward quark distributions, the Gegenbauer moments of the $D$-term, and the forward limit of the GPD $E$. The model is designed primarily for small and medium-size values of $x_B$, $x_B\le 0.2$. We examine two different models of the $t$ dependence of the GPDs: the factorized exponential model and the nonfactorized Regge-motivated model. Using our model, we successfully described the deeply virtual Compton scattering (DVCS) cross section measured by H1 and ZEUS, the moments of the beam-spin $A_{\mathrm{LU}}^{\sin \varphi }$, the beam-charge $A_C^{\cos \varphi }$, and the transversely polarized target $A_{\mathrm{UT}}^{\sin \phi \cos \varphi }$ DVCS asymmetries measured by HERMES and $A_{\mathrm{LU}}^{\sin \varphi }$ measured by CLAS. The data on $A_C^{\cos \varphi }$ prefer the Regge-motivated model of the $t$ dependence of the GPDs. The data on $A_{\mathrm{UT}}^{\sin \phi \cos \varphi }$ indicate that the $u$ and $d$ quarks carry only a small fraction of the proton total angular momentum.