ﻻ يوجد ملخص باللغة العربية
Using a mechanism which allows naturally small Dirac neutrino masses and its linkage to a dark gauge $U(1)_D$ symmetry, a realistic Dirac neutrino mass matrix is derived from $S_3$. The dark sector naturally contains a fermion singlet having a small seesaw mass. It is thus a good candidate for freeze-in dark matter from the decay of the $U(1)_D$ Higgs boson.
In 2006, a simple extension of the Standard Model was proposed in which neutrinos obtain radiative Majorana masses at one-loop level from their couplings with dark matter, hence the term scotogenic, from the Greek scotos meaning darkness. Here an ana
We investigate whether right-handed neutrinos can play the role of the dark matter of the Universe and be generated by the freeze-out production mechanism. In the standard picture, the requirement of a long lifetime of the right-handed neutrinos impl
We investigate a minimal neutrino portal dark matter (DM) model where a right-handed neutrino both generates the observed neutrino masses and mediates between the SM and the dark sector, which consists of a fermion and a boson. In contrast to earlier
We consider the Peccei-Quinn (PQ) mechanism as the one behind the Dirac neutrino masses when these are generated through the $d=5$ effective operator $bar{L}tilde{H}N_Rphi$ at one loop level, with $phi$ being a Standard Model singlet scalar. In this
We carry out diagonalization of a $3times3$ Hermitian matrix of which Real component and Imaginary part are commutative and apply it to Majorana neutrino mass matrix $M=M_ u M_ u^dagger$ which satisfies the same condition. It is shown in a model-inde