Speaker
Dr
Emiliano Molinaro
(TUM)
Description
The scotogenic model is one of the simplest scenarios for physics beyond
the Standard Model that can account for neutrino masses and dark matter at
the TeV scale. It contains another scalar doublet and three additional singlet
fermions (Ni), all odd under a Z2 symmetry. We examine
the possibility that the dark matter candidate, N1, does not reach thermal
equilibrium in the early Universe so that it behaves as a Feebly Interacting
Massive Particle (FIMP). In that case, it is found that the freeze-in production
of dark matter is entirely dominated by the decays of the odd scalars. We
compute the resulting dark matter abundance and study its dependence with
the parameters of the model. The freeze-in mechanism is shown to be able to
account for the observed relic density over a wide range of dark matter masses,
from the keV to the TeV scale. In addition to freeze-in, the N1 relic density
receives a further contribution from the late decay of the next-to-lightest odd
particle, which we also analyze. Finally, we consider the possibility that the
dark matter particle is a WIMP but receives an extra contribution to its relic
density from the decay of the FIMP (N1). In this case, important signals at
direct and indirect detection experiments are generally expected.
Author
Dr
Emiliano Molinaro
(TUM)
