Description
Naturalness problem has been one of the most urgent problem of the Standard Model, which have induced a variety of new physics models to suggest lesser fine-tuned solution to the light Higgs mass. As of the recent Higgs discovery at 126 GeV mass, it is not a phenomenological requirement to find a plausible Higgs mass value. Rather, what kind of model can accommodate 126 GeV Higgs more naturally than the others.
In this talk, we review several main versions of fine-tuning measure and discuss what feature of cancellation they are focusing on. Different definitions of fine-tuning claim the naturalness of a model differently, and the preferred parameter regions for a given model not necessarily the same. We focus on the example of the mSUGRA/CMSSM case, then finally the NMSSM which is believed to loosen the hierarchy problem of the Higgs mass of the MSSM.