Nearly degenerate heavy sterile neutrinos in cascade decay: mixing and oscillations

Understand

Some extensions beyond the Standard Model propose the existence of nearly degenerate heavy sterile neutrinos.

• If kinematically allowed these can be resonantly produced and decay in a cascade to common final states.
• The common decay channels lead to mixing of the heavy sterile neutrino states and interference effects.
• We implement non-perturbative methods to study the dynamics of the cascade decay to common final states, which features similarities but also noteworthy differences with the case of neutral meson mixing.