  We study the possibilities to detect Majorana neutrinos in $e^- \gamma$
colliders for different center of mass energies.
  We study the $W^- W^- l_j^{+}(l_j^+\equiv e^+ ,\mu^+ ,\tau^+)$ final state
which are, due to leptonic number violation, a clear signature for intermediate
Majorana neutrino contribution. Such a signal (final lepton have the opposite
charge of the initial lepton) is not possible if the heavy neutrinos are Dirac
particles. In our calculation we use the helicity formalism to obtain analytic
expressions for the amplitude and we have considered that the intermediate
neutrinos can be either on shell or off shell. Finally we present our results
for the total cross-section and for the angular distribution of the final
lepton. We also include a discussion on the expected events number as a
function of the input parameters.

High Energy Physics - Phenomenology