Majorana Neutrinos: From Mesons to the LHC

Sterile neutrinos are strongly motivated both from theoretical considerations and experimental searches. Observing lepton-number violating processes would be a decisive step toward establishing the Majorana nature of the neutrino mass. We first give a brief review of the tree-level seesaw models for neutrino Majorana mass generation. Because of the unknown scale associated with the neutrino mass generation, we must explore any scales experimentally accessible. We focus on the prospects of searching for Delta L = 2 processes, from the neutrino-less double-beta decay, muon-electron conversion, decays of mesons and heavy leptons, to experiments at the lepton and hadron colliders. We also present the possible flavor correlations between the neutrino oscillation parameters and the collider signatures.