  Low-scale models of neutrino mass generation often feature sterile neutrinos
with masses in the GeV-TeV range, which can be produced at colliders through
their mixing with the Standard Model neutrinos. We consider an alternative
scenario in which the sterile neutrino is produced in the decay of a heavier
particle, such that its production cross section does not depend on the
active-sterile neutrino mixing angles. The mixing angles can be accessed
through the decays of the sterile neutrino, provided that they lead to
observable displaced vertices. We present an explicit realization of this
scenario in which the sterile neutrino is the supersymmetric partner of a
pseudo-Nambu-Goldstone boson, and is produced in the decays of higgsino-like
neutralinos and charginos. The model predicts the active-sterile neutrino
mixing angles in terms of a small number of parameters. We show that a sterile
neutrino with a mass between a few 10 GeV and 200 GeV can lead to observable
displaced vertices at the LHC, and outline a strategy for reconstructing
experimentally its mixing angles.
