Isosinglet neutral heavy lepton production in high energy e-γ collisions

We evaluate the potential for searching for isosinglet neutral heavy leptons (N), such as right-handed neutrinos, in the next generation of e⁺e^- linear colliders, paying special attention to contributions from the various γe→WN initiated by photons from beamstrahlung and laser back-scattering. We find that these mechanisms are both competitive and complementary to the standard e⁺e^-→νN annihilation processe for producing neutral heavy leptons in these machines and greatly extends the search range over HERA and LEP200.