Related papers: U(1) textures and Lepton Flavor Violation
Leptoquarks (LQs) have been extensively studied in the context of $B$ anomalies. When $U(1)_{L_\mu-L_\tau}$ is introduced to a scalar LQ model with the LQ $S_1$ charged under the new symmetry, $S_1$ primarily couples to the third-generation…
In this paper, we present solutions to the fermion mass hierarchy problem in the context of the minimal supersymmetric standard theory augmented by an anomalous family-dependent U(1)_X symmetry. The latter is spontaneously broken by…
We survey the lepton flavor violation branching ratios Br(mu->e,gamma), Br(tau->mu,gamma), and Br(tau->e,gamma) in mSUGRA for a broad class of lepton mass matrix textures that give nearly tribimaximal lepton mixing. Small neutrino masses…
We investigate a gauge extension of the Standard Model in light of the observed hints of lepton universality violation in $b \to c \ell \nu$ and $b \to s \ell^+ \ell^-$ decays at BaBar, Belle and LHCb. The model consists of an extended…
The flavor problem, neutrino physics and the fermion mass hierarchy are important motivations to extend the Standard Model into the TeV scale. A new family non-universal extension is presented with three Higgs doublets, one Higgs singlet…
I report low energy results on the study of fermion masses and mixing for quarks and leptons, including neutrinos within a SU(3) flavor symmetry model, where ordinary heavy fermions, top and bottom quarks and tau lepton become massive at…
We show that most features of the mass and mixing pattern of the second and third SM fermion families can be accounted for without making use of flavour symmetries or other types of flavour dynamics. We discuss the implications for flavour…
Dirac leptogenesis (or Dirac neutrinogenesis), in which neutrinos are purely Dirac particles, is an interesting alternative to the standard leptogenesis scenario. In its supersymmetric version, the modified form of the superpotential…
The flavor structure of quarks and leptons is not yet fully understood, but it hints a more fundamental theory of non-universal generations. We therefore propose a simple extension of the Standard Model by flipping (i.e., enlarging) the…
We discuss the characteristic low energy phenomenological implications of an SU(5) Supersymmetric Grand Unified Theory (SUSY GUT) whose flavour structure is controlled by the family symmetry S4 x U(1), which provides a good description of…
We study the implications of the global U(1)R symmetry present in minimal lepton flavor violating implementations of the seesaw mechanism for neutrino masses. In the context of minimal type I seesaw scenarios with a slightly broken U(1)R,…
In recent years, many people have studied the possibility that the anomalous U(1) gauge symmetry is a trigger of SUSY breaking and/or an origin of the fermion mass hierarchy. Though it is interesting that the anomalous U(1) symmetry may…
We build upon a simple $U(2)_F$ model of flavor, in which all fermion masses and mixing hierarchies arise from powers of two small parameters controlling $U(2)_F$ breaking. In the original formulation, an isomorphism to the discrete…
Considering the constraints from the experimental data on $\mu\rightarrow e\gamma$, $\mu\rightarrow3e$, $\mu-e$ conversion etc., we analyze the Lepton Flavor Violating decays $\phi(J/\Psi,\Upsilon(1S)) \rightarrow e^+\mu^-(\mu^+\tau^-)$ in…
A grand unified $SU(5)$ theory is constructed with a hierarchical breaking of a $U(2)$ flavor symmetry. The small parameters of the squark and slepton mass matrices, necessary to solve the supersymmetric flavor-changing problem, and the…
We investigate lepton flavor violation in the context of intersecting D-brane models. We point out that these models have a source to generate flavor violation in the trilinear scalar couplings while the geometry of the construction leads…
We have built a renormalizable $U(1)_X$ model with a $\Sigma (18)\times Z_4$ symmetry, whose spontaneous breaking yields the observed SM fermion masses and fermionic mixing parameters. The tiny masses of the light active neutrinos are…
The heavy right-handed neutrinos in supersymmetric models can act as the source of lepton flavor violation (LFV). LFV processes like $ \mu \rightarrow e \gamma $, $ \tau \rightarrow \mu \gamma $, $ \tau \rightarrow e \gamma $ is an…
There have been many theoretical models constructed which aim to explain the neutrino masses and mixing patterns. While many of the models will be eliminated once more accurate determinations of the mixing parameters, especially $\sin^2…
We propose a framework that links the origin of the Standard Model flavour hierarchies to the generation of asymmetric dark matter via leptogenesis. The key new ingredient is a gauged $SO(3)$ flavour symmetry acting on both the visible and…