相关论文: Neutrino Masses from Loop-Induced Dirac Yukawa Cou…
We perform a systematic study of the Dirac neutrino masses which arise from a dimension five effective operator with a singlet scalar. We identify all possible realizations of this operator at tree level and one-loop level. The…
If neutrinos are Dirac fermions, certain new physics beyond the standard model should exist to account for the smallness of neutrino mass. With two additional scalars and a heavy intermediate fermion, in this paper, we systematically study…
We demonstrate that Dirac neutrino masses in the experimentally preferred range are generated within supersymmetric gauge extensions of the Standard Model with a generalized supersymmetry breaking sector. If the usual superpotential Yukawa…
A neutrino mass model is suggested within an $SU(4)\times U(1)$ -- electroweak theory. The smallness of neutrino masses can be guaranteed by a seesaw mechanism realized through Yukawa couplings to a scalar $SU(4)$-decuplet. In this scheme…
We investigate a simple model of neutrino mass based on SU(3)_C X SU(3)_L X U(1)_X gauge unification. The Yukawa coupling of the model has automatic lepton-number symmetry which is broken only by the self-couplings of the Higgs boson. At…
We consider the generation of neutrino masses via a singly-charged scalar singlet. Under general assumptions we identify two distinct structures for the neutrino mass matrix. This yields a constraint for the antisymmetric Yukawa coupling of…
It is shown how pure Dirac neutrino masses can naturally occur at low energies even in the presence of Planck scale lepton number violation. The geometrical picture in five dimensions assumes that the lepton number symmetry is explicitly…
We extend the scalar sector of the neutrinophilic two Higgs doublet model, where small masses of Dirac neutrinos are obtained via a small vacuum expectation value v_nu of the neutrinophilic SU(2)_L-doublet scalar field which has a Yukawa…
We study the models with the Majorana neutrino masses generated radiatively by two-loop diagrams due to the Yukawa $\rho \bar \ell_R^c \ell_R$ and effective $\rho^{\pm\pm} W^\mp W^\mp$ couplings along with a scalar triplet $\Delta$, where…
We classify models of the Dirac neutrino mass by concentrating on flavor structures of the mass matrix. The advantage of our classification is that we do not need to specify detail of models except for Yukawa interactions because flavor…
We explore a gauged $U(1)_{B-L}$ extension of standard model with inclusion of three right-handed neutrinos of exotic $B-L$ charges to cancel the gauge anomaly. Non-trivial transformation of new particles under $B-L$ symmetry forbids the…
We assume the universal Yukawa coupling (democratic mass matrix) with small violations for quarks, charged leptons and neutrinos masses. We could reproduce the mass hierarchy for quark masses and V_{CKM} matrix elements precisely. We adopt…
If the observed light neutrino masses are induced by their Yukawa couplings to singlet right-handed neutrinos, natural smallness of those renders direct collider tests of the electroweak scale neutrino mass mechanisms almost impossible both…
We study how tiny Dirac neutrino masses consistent with experimental constraints can arise in string theory SM-like vacua. We use as a laboratory 4d ${\cal N}=1$ type IIA Calabi--Yau orientifold compactifications, and in particular recent…
We study the generation of small neutrino masses from the dimension six effective operator at tree level and one-loop level, the neutrinos are assumed to be Dirac particles. We find out all possible tree and one-loop diagrams which lead to…
We propose a radiative Dirac neutrino mass model stabilized by a non-invertible fusion rule originating from a $Z_3 \times Z_3'$ gauging. The imposed symmetry forbids tree-level Yukawa couplings and ensures that neutrino masses are…
We present a model where Majorana neutrino mass terms are forbidden by the flavor symmetry group Delta(27). Neutrinos are Dirac fermions and their masses arise in the same way as that of the charged fermions, due to very small Yukawa…
If there exist only three light neutrinos below the weak scale, the neutrino masses can arise by breaking the lepton number L. One example is the Zee mechanism for the neutrino masses. We study phenomenological implications of neutrino…
We consider the supersymmetric seesaw mechanism induced by the exchange of heavy SU(2)_W triplet states, rather than `right-handed' neutrino singlets, to generate neutrino masses. We show that in this scenario the neutrino flavour structure…
We propose a new gauged $B-L$ extension of the standard model where light neutrinos are of Dirac type, naturally acquiring sub-eV mass after electroweak symmetry breaking, without any additional global symmetries. This is realised by…