We analyze the viability of the Zee-Babu model as an explanation of observed neutrino masses and mixings and the possibility that the model is confirmed or discarded in experiments planned for the very close future. The allowed parameter space is studied analytically by using some approximations and partial data. Then, a complete scanning of all parameters and constraints is performed numerically by using Monte Carlo methods. The cleanest signal of the model will be the detection of the doubly charged scalar at the LHC and its correlation with measurements of the branching ratio of $\mu \to e\gamma$ at the MEG experiment. In addition, the model offers interesting predictions for ${\tau }^{-}\to {\mu }^{+}{\mu }^{-}{\mu }^{-}$ experiments, lepton-hadron universality tests, the ${\theta }_{13}$ mixing in neutrino oscillations and the $⟨m_{\nu }{⟩}_{ee}$ parameter of neutrinoless double beta decay.

• Received 10 March 2008

DOI:https://doi.org/10.1103/PhysRevD.77.093013