Related papers: Flavor Hierarchy From F-theory
On the basis of the Froggatt-Nielsen mechanism, we study quark flavor mixings in the $SU(6) \times SU(2)_R$ model. The characteristic structure of the CKM matrix is attributed to the hierarchical effective Yukawa couplings due to the…
A Supersymmetric Grand unified model is constructed based on SO(10)xSO(10) symmetry in which new types of Yukawa matrices couple standard and exotic fermions. Evolution of these couplings from the Grand Unified scale to the electroweak…
We show that solutions for the masses and mixings of the quarks and leptons based on a $U(1)\times Z_2$ horizontal symmetry are possible. The seesaw mechanism is shown to work consistently in the presence of the discrete symmetry. The…
We study a class of supersymmetric Froggatt-Nielsen (FN) models with multiple U(1) symmetries and Standard Model (SM) singlets inspired by heterotic string compactifications on Calabi-Yau threefolds. The string-theoretic origin imposes a…
In this note we investigate U(N) gauge theories with matter in the fundamental and adjoint representations of the gauge group, interacting via generalized Yukawa terms of the form Tr[Q \Phi^n {\tilde Q}]. We find agreement between the…
We consider the effects of departures from minimal flavour violations (MFV) in the context of CMSSM-like theories. Second and third generation off-diagonal elements in the Yukawa, sfermion, and trilinear mass matrices are taken to be…
We construct a supersymmetric model based on $T'\otimes Z_3\otimes Z_9$ flavor symmetry. At the leading order, the charged lepton mass matrix is not diagonal, $T'$ is broken completely, and the hierarchy in the charged lepton masses is…
In a class of F-theory SU(5) GUTs the low energy chiral mass spectrum is obtained from rank one fermion mass textures with a hierarchical structure organised by U(1) symmetries embedded in the exceptional E_8 group. In these theories chiral…
Based on the hierarchy exhibited by quarks masses at low energies, we assume that Yukawa couplings of up and down quarks are related by $Y_u\propto Y_d^2$ at grand unification scales. This ansatz gives rise to a symmetrical CKM matrix at…
The unification of the quark and charged lepton flavor structures is revisited using the tools of Minimal Flavor Violation (MFV). Under that framework, we first identify a unique point in parameter space where flavor universality is…
We propose that the flavor structure of the quark sector of the Standard Model is determined by a vectorial SU(2) flavor symmetry, which we dub Flavorspin, under which quarks transform as triplets. The fundamental Yukawa couplings are real…
Constrained Sequential neutrino Dominance of type 2 (referred to as CSD2) is an attractive building block for flavour Grand Unified Theories (GUTs) because it predicts a non-zero leptonic mixing angle $\theta_{13}^\text{PMNS}$, a deviation…
We propose a model of fermion masses and mixings based on $SU(5)$ grand unified theory (GUT) and a $D_{4}$ flavor symmetry. This is a highly predictive 4D $SU(5)$ GUT with a flavor symmetry that does not contain a triplet irreducible…
We explore predictive flavor models based on subgroups of the standard-model $SU(3)^5$ flavor symmetry. Restricting to products of $SU(3)$, we find that a global $SU(3)^3$ flavor symmetry, broken only by two Yukawa spurions, leads to a…
We investigate the Yukawa sector for up-like quarks in the Lee's version of the Littlest Higgs model. We derive general quark mass and mixing formulae and study leading order contributions due to non-zero light quark masses. Relying on the…
We investigate the possibility of constructing models of R-violating LQD Yukawa couplings using a single U(1) flavour-symmetry group and supermultiplet charge assignments that are compatible with the known hierarchies of quark and lepton…
The U(1) flavor symmetry explains the large mixing of neutrinos while it leads to the unique texture for the quark mass matrices. It is remarked that U(1) symmetric mass matrices have the phenomenological defects. In the quark sector, the…
We discuss the $SU(5)$ grand unified extension of flavour models with multiple modular symmetries. The proposed model involves two modular $S_4$ groups, one acting in the charged fermion sector, associated with a modulus field value…
We compute the finite renormalisation of the Cabibbo-Kobayashi-Maskawa (CKM) matrix induced by gluino-squark diagrams in the MSSM with non-minimal sources of flavour violation. Subsequently we derive bounds on the flavour-off-diagonal…
Models involving a U(2) flavor symmetry, or any of a number of its non-Abelian discrete subgroups, can explain the observed hierarchy of charged fermion masses and CKM angles. It is known that a large neutrino mixing angle connecting second…