Speaker
Description
We propose a Dirac neutrino portal dark matter scenario by minimally extending the particle content of the Standard Model (SM) with three right-handed neutrinos, a Dirac fermion dark matter candidate, and a complex scalar, all of which are singlets under the SM gauge group. symmetry $Z_4$ has been introduced for the stability of dark matter candidates and also to ensure the Dirac nature of light neutrinos at the same time. We studied both thermal and non-thermal dark matter scenarios and the possibility of probing such scenarios through the contribution to the effective relativistic degrees of freedom $\Delta{N_{\rm eff}}$. We also check the stringent constraints on the free-streaming length of such freeze-in DM from structure formation requirements. Such constraints can rule out DM mass all the way up to $\mathcal{O}$(100 keV).
| Secondary category for the parallel session (optional) | Astroparticle Physics |
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