A renormalization group analysis of the Hill model and its HEIDI extension

The parameter space of the simplest extension of the standard model is studied in the light of the 125 GeV Higgs boson discovery. The Hill model extends the scalar sector of the standard model with a real singlet, that mixes with the standard model Higgs boson only via cubic interactions. The two-loop standard model renormalization group equations are completed with the one-loop Hill equations. Stability up to the Planck scale is possible without tension with the other parameters. An extension with more singlet fields, in particular a higher-dimensional (HEIDI) field, is presented.