Understand
We study the possibility of singlet fermion dark matter (DM) and successful leptogenesis in minimal scotogenic model which also provides a common origin of DM and light neutrino masses.
- In this scenario, where the standard model (SM) is extended by three gauge singlet fermions and one additional scalar doublet, all odd under an in-built $Z_2$ symmetry, the lightest singlet fermion which also happens to be the lightest $Z_2$ odd particle, can be either thermal or non-thermal DM candidate depending upon the strength of its couplings with SM leptons and the $Z_2$ odd scalar doublet.
- In both the scenarios, the $Z_2$ odd scalar doublet plays a non-trivial role either by assisting coannihilation with thermal DM or by providing a source for non-thermal DM via decay.
- The heavier $Z_2$ odd singlet fermion produces a net lepton asymmetry through its out-of-equilibrium decay into SM leptons and $Z_2$ odd scalar doublet.