Production of the doubly charged leptons at the high-energy linear e+ e- colliders

We consider production of the doubly charged leptons X±± via e+e−, γγ and eγ collisions at the high-energy linear e+e− colliders. It is found that, due to the smallness of the mixing parameter ve, the production cross section for the subprocess eγ → X−−W+ is too small to be used to study the possible signatures of the doubly charged leptons. However, the processes and , are not this case. As long as the doubly charged leptons are not too heavy, they can be abundantly produced via these two processes at the high-energy linear e+e− colliders.