Related papers: Models of Lepton and Quark Masses
The generation of the fermion mass hierarchy in the standard model of particle physics is a long-standing puzzle. The recent discoveries from neutrino physics suggests that the mixing in the lepton sector is large compared to the quark…
In the generation structure, the quark mass increases extremely rapidly with the increase of generation index, and there is the bound for generation number. The ground for this bound is investigated on the basis of a certain kind of…
We present model independent constraints on the masses and couplings to fermions of $B$ and $L$ conserving leptoquarks. Such vector or scalar particles could have masses below 100 GeV and be produced at HERA; we list the generation…
Reliable values of quark and lepton masses are important for model building at a fundamental energy scale, such as the Fermi scale M_Z \approx 91.2 GeV and the would-be GUT scale \Lambda_GUT \sim 2 \times 10^16 GeV. Using the latest data…
We analyze the structure of quark and lepton mass matrices under the hypothesis that they are determined from a minimum principle applied to a generic potential invariant under the $\left[SU(3)\right]^5\otimes \mathcal O(3)$ flavor…
If neutrinos have masses, why are they so tiny? Are these masses of the Dirac type or of the Majorana type? We are already familiar with the mechanism of how to obtain a tiny Majorana neutrino mass by the famous see-saw mechanism. The…
Relations between bulk mass parameters for fermions propagating in higher dimensions are studied in analogy with the empirical mass relation for charged leptons. Masses of three generation of four-dimensional charged leptons are achieved…
We propose a unified mass matrix model for quarks and leptons, in which sixteen observables of mass ratios and mixings of the quarks and neutrinos are described by using no family number-dependent parameters except for the charged lepton…
In preon models based on chiral gauge theories, we show that light composite fermions can ensue as a result of gauging a subset of preons in a vector-like manner. After demonstrating how this mechanism works in a toy example, we construct a…
Possible existence of "hot-sector generations" above the well known 3 generation bound is investigated on the basis of a model of leptons and quarks, which is based on the Harari and Shupe's one. Our model predicts the existence of {\bf3 +…
We present a one-doublet extended technicolor model, with all fermions in fundamental representations. The bare lagrangian has no explicit mass terms but generates masses through gauge symmetry breaking by purely QCD-like dynamics. The…
We present a new model of radiative neutrino mass generation wherein TeV scale leptoguark scalars induce tiny neutrino masses as two-loop radiative corrections. The neutrino oscillation parameter \sin^2\theta_{13} is predicted to be close…
In this talk I review the `puzzles' associated with the fermion mass matrices and describe some recent attempts to resolve them, at least partially. Models which attempt to explain the observed mass hierarchy as arising from radiative…
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…
We suggest an approach to explain the observed pattern of the neutrino masses and mixing which employs the weakly broken quark-lepton symmetry and does not require introduction of an ad hoc symmetry of the neutrino sector. The mass matrices…
We propose the lepton mixing matrix at high energy scale to be connected to quark mixing matrix by the similar transformation. The similarity between CKM and PMNS significantly narrows down the ranges in physical parameters. The condition…
The approach unifying all the internal degrees of freedom--proposed by one of us--is offering a new way of understanding families of quarks and leptons: A part of the starting Lagrange density in d(=1+13), which includes two kinds of spin…
Quark mass ratios are expressed within the linear meson model by universal relations involving only the masses and decay constants of the flavored pseudoscalars as well as their wave function renormalization. Quantitative results are in…
Precision measurements of $Z$-boson parameters and $W$-boson and $t$-quark masses put strong constraints on non $SU(2)\times U(1)$ singlet New Physics. We demonstrate that one extra generation passes electroweak constraints even when all…
We demonstrate a common origin for high-scale leptogenesis and three-loop neutrino mass generation. Specifically we extend the standard model by two real singlet scalars, two singly charged scalars carrying different lepton numbers and two…