Numerical estimate of minimal active-sterile neutrino mixing for sterile neutrinos at GeV scale

Understand

Seesaw mechanism constrains from below mixing between active and sterile neutrinos for fixed sterile neutrino masses.

• Signal events associated with sterile neutrino decays inside a detector at fixed target experiment are suppressed by the mixing angle to the power of four.
• Therefore sensitivity of experiments such as SHiP and DUNE should take into account minimal possible values of the mixing angles.
• We extend the previous study of this subject arXiv:1312.2887 to a more general case of non-zero CP-violating phases in the neutrino sector.