Production of e+ e− pairs in proton-deuteron capture to 3He

The process p+d↔3He+γ∗ at intermediate energies is described using a covariant and gauge-invariant model, and a realistic pd3He vertex. Both photodisintegration of 3He and proton-deuteron capture with production of e+e− pairs are studied, and results for cross sections and response functions are presented. The effect of time-like form factors on the dilepton cross sections is investigated as well.