Scalar Products of Fermion Currents

Abstract A complete set of scalar products for vector, axial vector, scalar, and pseudoscalar currents of two massive fermions (lepton and nucleon) is reviewed. The scalar products are obtained for three physically different cases of the lepton spin and nucleon spin orientations. These expressions are needed at least for self-consistent calculations of cross sections for coherent (elastic) and incoherent (inelastic) interactions of massive neutral weakly interacting particles with nuclear targets utilized in the detectors intended for direct detection of galactic dark matter particles on Earth.