Form factors and generalized parton distributions in basis light-front quantization

We calculate the elastic form factors and the generalized parton distributions (GPDs) for four low-lying bound states of a demonstration fermion-antifermion system, strong-coupling positronium (eē), using basis light-front quantization (BLFQ). By using this approach, we also calculate the impact-parameter-dependent GPDs q(x,b) to visualize the fermion density in the transverse plane (b). We compare selected results with corresponding quantities in the nonrelativistic limit to reveal relativistic effects. Our results establish the foundation within BLFQ for investigating the form factors and the GPDs for hadronic systems.