State-of-the-Art Tests of Lepton Number Violation and Seesaw Mechanisms
The discoveries of nonzero neutrino masses and a SM-like Higgs force us to contemplate that Yukawa couplings may span at least 12 order of magnitude. However, permitting that lepton number is not a fundamental symmetry of nature at low energies, Seesaw mechanisms can alleviate this problem.This talk will focus on recent developments of two tests that directly probe the large class of Seesaw models that feature a heavy neutrino (Dirac, Pseudo-Dirac, or Majorana), in particular: heavy neutrino production via a resonant, s-channel W' (with arbitrary chiral couplings) and through W-photon fusion. The discovery potential of these production modes at current and future hadron colliders will be discussed in detail. Recent LHC results will also be addressed.