Radiative neutrino models and observational consequences

• Main Author: Ludkiewicz, Alexander
• Format: Others
• Language: English
• Published: KTH, Teoretisk partikelfysik 2011
• Subjects: Radiative mechanisms; scotogenic model; Zee–Babu model; fourth generation of leptons
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-42593

We give a general introduction to physics, in particular the physics of the Standard Model (SM). Next we discuss one of the problems the SM faces, that of accommodating the neutrino masses. We discuss the concept of radiative mechanisms. Then we study three particular such models in depth. The first is a model due to Ma which introduces three neutrino singlets and one scalar doublet on top of the SM particle content. We discuss the different neutrino masses that this model can hold. It is found that only case of normal hierarchy among the neutrinos is allowed in this model. We also discuss several observable quantities currently being searched for in experiments, and their relation to this model The second model is due to Zee and Babu, and is commonly known as the Zee–Babu model. This model adds two electrically charged scalar particles to the SM. We find that this model can describe both the inverted hierarchy and normal hierarchy. The previously mentioned observable quantities are once again discussed, but with this model in mind. Finally we discuss a model which accounts for the neutrino masses by assuming that there exists a fourth generation of leptons. It is found that this framework is insufficient to describe the observed neutrino masses.