Phenomenological implications of “Majorana” sneutrinos at future accelerators

Abstract

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 $\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{m}{}_{1}^{2}\ensuremath{-}\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{m}{}_{2}^{2}=2|\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{m}{}_{M}^{2}|$. 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.