Impact of Observing Lepton Number Violation on Models of Baryogenesis

by Dr Julia Harz (LPTHE)

Wednesday 3 Feb 2016, 14:00 → 15:00 Europe/Paris

Grande Salle du Conseil

Different observations point us to physics beyond the Standard Model, for example the baryon asymmetry of the Universe. While a variety of successful models has been proposed, it is worthwhile to think about possibilities of narrowing down these options and to proceed in the question which mechanism is realised in nature. After a brief introduction, I will discuss why interactions that manifest themselves as lepton number violating processes at low energies in combination with sphaleron transitions typically washout any pre-existing baryon asymmetry of the Universe. Based on this, I will demonstrate that the observation of lepton number violating processes will set stringent limits on models of high-scale baryogenesis. First, I will discuss the potential of the LHC to model independently exclude high-scale leptogenesis scenarios when observing lepton number violating processes. Further, I will demonstrate in a model independent approach that the observation of neutrinoless double beta decay triggered via a non-standard mechanism would as well impose a stringent constraint on mechanisms of high-scale baryogenesis. Finally, I will show that in combination with the observation of lepton flavor violating processes, the argument can be further strengthened, closing the loophole of asymmetries being stored in different lepton flavors.