Related papers: The Fermion Mass Problem
In an attempt to understand the observed patterns of lepton and quark masses, models invoking a flavor symmetry $G_f$, under which the Standard Model generations are charged, have been proposed. One particularly successful symmetry, U(2),…
The fermion mass textures are discussed in the context of F-theory SU(5) GUT. The tree-level up, down and charged lepton Yukawa couplings are computed in terms of the integrals of overlapping wavefunctions at the intersection points of…
We perform a systematic study of the generic Gatto-Sartori-Tonin relation, $\tan^2\theta_{ij}= m_i/m_j$. This study of fermion mixing phenomena leads us to the necessary conditions that are needed in order to obtain it without any…
Some phenomenological aspects of a supersymmetric model for fermion mass hierarchy proposed previously are discussed. It is required that the lepton universality violation is near to its current experimental bound. The lepton number…
The scaling behavior of gauge couplings and fermion Yukawa couplings in the minimal supersymmetric model is discussed. The relevance of the top quark Yukawa coupling fixed point in establishing the top quark mass is described. The evolution…
In extending the minimal standard model of quarks and leptons to include supersymmetry, the conservation of baryon and lepton numbers is no longer automatic. I show how the latter may be achieved with a new U(1) gauge symmetry and new…
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…
The charged fermion masses of the three generations exhibit the two strong hierarchies m_3 >> m_2 >> m_1. We assume that also neutrino masses satisfy m_{nu 3} > m_{nu 2} > m_{nu 1} and derive the consequences of the hierarchical spectra on…
We present a new mechanism for solving the fermionic masses and mixing hierarchies of the standard model through a minimal symmetry $\mathcal{Z}_2 \times \mathcal{Z}_5$. The mechanism is also capable of explaining the neutrino masses and…
We discuss how predictions of Fritzsch textures can be consistent with values of fermion masses and mixing angles if we embed them in a supersymmetric grand unified theory.
In the context of the Grand Unified MSSM, we investigate the fermion mass matrices at GUT scale. We note that from the experimental mass pattern the determinants of the Yukawa matrices at this scale can be unified with good precision.…
Prompted by the recent better determination of the angles of the unitarity triangle, we re-appraise the problem of finding simple fermion mass textures, possibly linked to some symmetry principle and compatible with grand unification. In…
We propose a new $\mathrm{SU}(3)_C \otimes \mathrm{SU}(2)_{L}\otimes \mathrm{U}(1)_{Y}\otimes \mathrm{U}(1)_{X}$ gauge model which is non universal respect to the three fermion families of the Standard Model. We introduce additional one…
We consider a composite model in which the standard model fermions are bound states of elementary spin $\frac{1}{2}$ particles, the preons, situated in the conjugate product representation of the color group. In this framework we propose…
We show that the observed structure of quark and lepton masses and mixing angles can arise entirely geometrically from superstring constructions, at the renormalizable level. The model we consider is a $Z_3$ orbifold compactification of…
The masses of quarks and leptons suggest a strong hierarchical structure. We argue that their patterns can be reproduced through the introduction of a new Abelian symmetry. The data suggest that this symmetry is anomalous. We suggest that…
In view of the observed strong hierarchy of the quark and lepton masses and of the flavor mixing angles it is argued that the description of flavor mixing must take this into account. One particular interesting way to describe the flavor…
We investigate the flavour structure of generic extensions of the SM where quark and lepton mass hierarchies and the suppression of flavour-changing transitions originate only by the normalization constants of the fermion kinetic terms. We…
We suggest the fermion doubling for all quarks and leptons. It is a generalization of the neutrino doubling of the seesaw mechanism. The new quarks and leptons are $SU(2)$ singlets and carry the electromagnetic charges of their lighter…
We survey some of the recent promising developments in the search for the theory behind neutrino mass and tri-bimaximal mixing, and indeed all fermion masses and mixing. We focus in particular on models with discrete family symmetry and…