The Seesaw Mechanism and Renormalization Group Effects

Neutrino mass models predict masses and mixings typically at very high scales, while the measured values are determined at low energies. The renormalization group running which connects models with measurements is discussed in this paper. Analytic formulae for the running which include both Dirac- and Majorana CP phases are provided and they allow a systematic understanding of all effects. Some applications and numerical examples are shown.