  Quasi parton distributions (quasi-PDFs) are currently under intense
investigation. Quasi-PDFs are defined through spatial correlation functions and
are thus accessible in lattice QCD. They gradually approach their corresponding
standard (light-cone) PDFs as the hadron momentum increases. Recently, we
investigated the concept of quasi-distributions in the case of generalized
parton distributions (GPDs) by calculating the twist-2 vector GPDs in the
scalar diquark spectator model. In the present work, we extend this study to
the remaining six leading-twist GPDs. For large hadron momenta, all quasi-GPDs
analytically reduce to the corresponding standard GPDs. We also study the
numerical mismatch between quasi-GPDs and standard GPDs for finite hadron
momenta. Furthermore, we present results for quasi-PDFs, and explore
higher-twist effects associated with the parton momentum and the longitudinal
momentum transfer to the target. We study the dependence of our results on the
model parameters as well as the type of diquark. Finally, we discuss the lowest
moments of quasi distributions, and elaborate on the relation between
quasi-GPDs and the total angular momentum of quarks. The moment analysis
suggests a preferred definition of several quasi-distributions.
