Natural GUT scale mass ratios
Martin Spinrath (Karlsruhe University)

In my talk I will focus on two different kind of masses and discuss their naturalness. First, I will discuss ratios of fermion masses like the tau and the bottom mass at the SUSY GUT scale. These ratios are predicted in minimal GUT setups, but recent data hints that nature has chosen a more complicated setup. I will present alternatives and also show that these alternatives can be used to generate a sizeable theta_13 in the neutrino sector. Then I will focus on the little hierarchy problem and discuss naturalness in the MSSM. It turns out that even after the Higgs discovery there are still regions with an acceptable amount of fine-tuning allowed assuming non-universal gaugino masses at the GUT scale.