Electric dipole moments of three-nucleon systems in the pionless effective field theory

We calculate the electric dipole moments (EDMs) of three-nucleon systems at leading order in pionless effective field theory. The one-body contributions that arise from permanent proton and neutron EDMs and the two-body contributions that arise from CP-odd nucleon-nucleon interactions are taken into account. Neglecting the Coulomb interaction, we consider the triton and 3He, and also investigate them in the Wigner-SU(4) symmetric limit. We also calculate the electric dipole form factor and numerically find that the momentum dependence of the electric dipole form factor in the Wigner limit is, up to an overall constant (and numerical accuracy), the same as the momentum dependence of the charge form factor. In addition, we include the Coulomb interactions for calculating 3He charge form factors. Finally, we study the cutoff dependence of these observables and find that they are properly renormalized.