TeV Scale Leptogenesis in Extended Scotogenic Model
摘要
We explore the potential for low-scale leptogenesis in the singlet-triplet scotogenic model where dark matter participates in neutrino mass generation radiatively. Our investigation focuses on two possible scenarios. The first scenario introduces two heavy right-handed (RH) fermion fields, F and \(\Sigma \) , with moderate hierarchy. In this case, the out-of-equilibrium decay of these particles results in the emergence of a lepton asymmetry. Our analysis reveals that the scale of leptogenesis in this scenario resembles that of standard thermal leptogenesis with \(M_{F,\Sigma }\sim 10^{9}\) GeV. In the second scenario, we propose a framework to lower the scale of leptogenesis. In particular, we have considered two singlet fermions ( \(F_1\) , \(F_2\) ) and one triplet fermion ( \(\Sigma \) ), which results in non-zero lightest active neutrino mass, i.e. \(m_{1}\ne 0\) . With the mass hierarchy \(M_{F_{1}} < M_{\Sigma } \ll M_{F_{2}}\) , this scenario yields a lower bound on heavy RH fermion, significantly reducing the scale of leptogenesis up to the TeV range. Also, real component of the neutral part of inert scalar ( \(\eta \) ) is the dark matter candidate in the model.