Clues on the Majorana scale from scalar resonances at the LHC

Understand

In order to address the observation of the neutrino oscillations and the metastability of the Standard Model, we extend the fermion sector with two right-handed (i.e.

• sterile) neutrinos, and the scalar sector of the SM with a real scalar, the Hill field.
• The latter takes the role of a Majoron and generates the Majorana masses for the neutrino sector, such that the particle spectrum features two CP-even scalars $h_1$ and $h_2$, and also two heavy, mass degenerate neutrinos.
• When the $h_1$ is identified with the scalar resonance at ~125 GeV and the condition is imposed that the $h_1$ self coupling and its running vanish at the Planck scale, the scalar mixing and the vacuum expectation value of the Hill field are fixed by the $h_2$ mass.