相关论文: Quark and lepton mass matrices with $A_4$ family s…
The successful A4 family symmetry for leptons is applied to quarks, motivated by the quark-lepton assignments of SU(5). Realistic quark masses and mixing angles are obtained, in good agreement with data. In particular, we find a strong…
We present a model of quark and lepton masses and mixings based on A4 family symmetry, a discrete subgroup of an SO(3) flavour symmetry, together with Pati-Salam unification. It accommodates tri-bimaximal neutrino mixing via constrained…
It has been recently claimed that the symmetry group S4 yields to the Tri-bimaximal neutrino mixing in a "natural" way from the group theory point of view. Approving of this feature as an indication, we build a supersymmetric model of…
The neutrino mixing matrix has been measured to be of a form consistent with tribimaximal mixing, while the quark mixing matrix is almost diagonal. A scheme based on flavour A_4 symmetry for understanding these patterns simultaneously is…
If the standard model of quark interactions is supplemented by a discrete A_4 symmetry (which may be relevant for the lepton sector), the spontaneous breaking of the electroweak gauge symmetry allows arbitrary quark masses, but all mixing…
We discuss whether quark, charged lepton and neutrino masses and mixing angles may be related by an extended flavour and family symmetry group. We show that current measurements of all fermion masses and mixing angles are consistent with a…
We propose a model for the quark masses and mixings based on an A_4 family symmetry. Three scalar SU(2) doublets form a triplet of A_4. The three left-handed-quark SU(2) doublets are also united in a triplet of A_4. The right-handed quarks…
To a first approximation, the quark mixing matrix has $\theta^q_{13} = \theta^q_{23} = 0$, whereas the lepton mixing matrix has $\theta^l_{23} = \pi/4$. We show how this structure may be understood if the family symmetry is $Q_8$, the…
Following the newly formulated notion of form invariance of the neutrino mass matrix, a complete model of leptons is constructed. It is based on a specific unitary 3 X 3 matrix U in family space, such that U^2 is the simple discrete…
The discrete non-Abelian symmetry $A_4$, valid at some high-energy scale, naturally leads to degenerate neutrino masses, without spoiling the hierarchy of charged-lepton masses. Realistic neutrino mass splittings and mixing angles (one of…
We build a supersymmetric model of quark and lepton masses based on the discrete flavour symmetry group T', the double covering of A_4. In the lepton sector our model is practically indistinguishable from recent models based on A_4 and, in…
Recently Babu, Ma and Valle proposed a model of quark and lepton mixing based on $A_4$ symmetry. Within this model the lepton and slepton mixings are intimately related. We perform a numerical study in order to derive the slepton masses and…
We propose a realistic A4 extension of the Standard Model involving a particular quark-lepton mass relation, namely that the ratio of the third family mass to the geometric mean of the first and second family masses are equal for down-type…
We present a supersymmetric model of quark and lepton based on $S_4\times Z_3\times Z_4$ flavor symmetry. The $S_4$ symmetry is broken down to Klein four and $Z_3$ subgroups in the neutrino and the charged lepton sectors respectively.…
Recent neutrino data have been favourable to a nearly bimaximal mixing, which suggests a simple form of the neutrino mass matrix. Stimulated by this matrix form, a possibility that all the mass matrices of quarks and leptons have the same…
Based on a supersymmetric Yukawaon model with O(3) family symmetry, possible forms of quark and lepton mixing matrices are systematically investigated under a condition that the up-quark mass matrix form leads to the observed nearly…
We study the flavour sector in models where the three families of matter are unified in a $(16,3)$ representation of the $SO(10)\times A_4$ group. The necessary ingredients to realize tri-bi-maximal mixing in the lepton sector are…
We address two fundamental aspects of flavor physics: the mass hierarchy and the large lepton mixing angles. On one side, left-right flavor symmetry realizes the democratic mass matrix patterns and explains why one family is much heavier…
The cubic symmetry S_4 contains A_4 and S_3, both of which have been used to study neutrino mass matrices. Using S_4 as the family symmetry of a complete supersymmetric theory of leptons, it is shown how the requirement of breaking S_4 at…
We consider a model for quark and lepton masses and mixings based on S4 flavor symmetry. The model contains six Higgs doublets where three of them give mass to the leptons and the other three gives mass to the quarks. Charged fermion and…