Phenomenological implications of “Majorana” sneutrinos at future accelerators

It has recently been shown that in the framework of weak-scale softly broken supersymmetry the existence of a Majorana neutrino inevitably implies a finite (B-L)-violating “Majorana” mass $m_M$ for scalar neutrinos, with the effect of splitting the complex sneutrino field into two real fields separated in mass by $\tilde{m}{}_1^2-\tilde{m}{}_2^2=2\mathrm{}|\tilde{m}{}_M^2|$. The existence of a finite Majorana sneutrino mass leads to new processes potentially observable at future colliders. Taking into account existing low-energy constraints, to find positive signals for electron sneutrinos will be very difficult, although not impossible. For muon and tau sneutrinos a dedicated search for Majorana masses has much better prospects.