Poincaré covariant current operator and elastic electron-deuteron scattering in the front-form Hamiltonian dynamics

The deuteron electromagnetic form factors, ${A(Q}^2)$ and ${B(Q}^2),$ and the tensor polarization $T_{20}{(Q}^2),$ are unambiguously calculated within the front-form relativistic Hamiltonian dynamics, by using a novel current, built up from one-body terms, which fulfills Poincaré, parity, and time reversal covariance, together with Hermiticity and the continuity equation. A simultaneous description of the experimental data for the three deuteron form factors is achieved up to $Q^2<0.4\mathrm{}\hspace{0.5em}(\mathrm{GeV}{/c)}^2.$ At higher momentum transfer, different nucleon-nucleon interactions strongly affect ${A(Q}^2),$ ${B(Q}^2),$ and $T_{20}{(Q}^2),$ and the effects of the interactions can be related to S-state kinetic energy in the deuteron. Different nucleon form factor models have huge effects on ${A(Q}^2),$ smaller effects on ${B(Q}^2),$ and essentially none on $T_{20}{(Q}^2).\mathrm{}$