Systematic model building with flavor symmetries [Elektronische Ressource] / by Florian Plentinger

Julius–Maximilians–Universität WürzburgInstitut für Theoretische Physik und AstrophysikLehrstuhl für Theoretische Physik IIUniv.-Prof. Dr. Reinhold RücklSystematic Model BuildingwithFlavor SymmetriesbyDipl.-Phys. Univ. Florian PlentingerComplete printout of the dissertation for the attainment of the doctoral degree approvedby the faculty of physics and astrophysics of Würzburg UniversityDoktor der Naturwissenschaften (Dr. rer. nat.)AbstractThe observation of neutrino masses and lepton mixing has highlighted the incompletenessoftheStandardModelofparticlephysics. Inconjunctionwiththisdiscovery,newquestionsarise: why are the neutrino masses so small, which form has their mass hierarchy, why isthemixinginthequark andlepton sectors sodifferent orwhat isthe structureof theHiggssector. Inorder to address these issuesand to predict future experimental results, differentapproaches are considered. One particularly interesting possibility, are Grand UnifiedTheories such as SU(5) or SO(10). GUTs are vertical symmetries since they unify theSM particles into multiplets and usually predict new particles which can naturally explainthe smallness of the neutrino masses via the seesaw mechanism. On the other hand, alsohorizontal symmetries, i.e., flavor symmetries, acting on the generation space of the SMparticles, are promising. They can serve as an explanation for the quark and lepton masshierarchies as well as for the different mixings in the quark and lepton sectors.