Related papers: Gravitational anomaly and fundamental forces
Under a reasonable set of ab-initio assumptions, we define and chart the atlas of simple gauge theories with families of fermions whose masses are forbidden by gauge invariance. We propose a compass to navigate the atlas based on counting…
It is shown that extending Osp(4/1) supergravity to quaternion co-ordinates to get HU(4/1) gives the standard model with 3 generations of fermions, U(1)xSU(2)xSU(3) bosons plus 2 gravitinos, 1 graviton, and nothing else. It is shown using…
The gauge symmetry of the Standard Model is SU(3)_c x SU(2)_L x U(1)_Y for unknown reasons. One aspect that can be addressed is the low dimensionality of all its subgroups. Why not much larger groups like SU(7), or for that matter, SP(38)…
In the framework of the four dimensional heterotic superstring with free fermions we present a revised version of the rank eight Grand Unified String Theories (GUST) which contain the $SU(3)_H$-gauge family symmetry. We also develop some…
Motivated by experimental measurements indicating deviations from the Standard Model predictions we discuss F-theory inspired models, which, in addition to the three chiral generations contain a vector-like complete fermion family. The…
A direct consequence of the occurrence of fermion families is the invariance of currents under certain groups of (universality) transformations. We show how these universality groups can themselves be used to find and study grand family…
The success of the Higgs mechanism in the standard model has led to the speculation that the standard model gauge group might arise through an analogous breaking of a yet more unified group. Such `grand unified theories' have the advantage…
We consider the extended electroweak gauge group SU(2)_1 \times SU(2)_2 \times U(1)_Y where the first and second families of fermions couple to SU(2)_1 while the third family couples to SU(2)_2. Bounds based an precision electroweak…
The fermionic sector of the Standard Model of Elementary Particles emerges as the low energy limit of a single fermionic field freely propagating in a higher dimensional background. The local geometrical framework is obtained by enforcing…
Flavourful extensions of the Standard Model aimed at explaining its fermionic mass structure typically rely on symmetries, broken at high-energy scales far beyond the reach of foreseeable direct collider searches. We illustrate, using a…
The clockwork mechanism, which can naturally explain the origin of small numbers, is implemented in $SO(10)$ grand unified theories to address the origin of hierarchies in fermion masses and mixings. We show that a minimal Yukawa sector…
Although there have been many experimental and theoretical efforts to measure and interpret small deviations from the standard model of particle physics, the gap that the model leaves in understanding why there are only three generations of…
The hypercharges of the fermions are not uniquely determined in SO(10) grand unification, but rather depend upon which linear combination of the two U(1) subgroups of SO(10) > SU(3) X SU(2) X U(1) X U(1) remains unbroken. We show that, in…
We obtain three generation SU(3)_c X SU(2)_L X U(1)_Y string models in all of the exactly solvable (0,2) constructions sampled by fermionization. None of these examples, including those that are symmetric abelian orbifolds, rely on the Z_2…
The heaviness of the third family fermions and the experimental absence of large flavor violating processes suggest, in supersymmetric theories, that the three families belong to a $2+1$ representation of a horizontal symmetry $G_H$. In…
An analysis of generating fermion masses via cubic couplings in SO(10) grand unification with a unified Higgs sector is given. The new framework utilizes a single pair of vector--spinor representation $144+\bar{144}$ to break the gauge…
We describe higher-dimensional theories whose low-energy 4D descriptions contain larger gauge or global symmetry groups. As an example, we construct a Higgsless SU(2) x U(1) model of electroweak symmetry breaking. The 5D SU(2) gauge…
In the context of the free-fermionic formulation of the heterotic superstring, we construct a three generation N=1 supersymmetric SU(4)xSU(2)LxSU(2)R model supplemented by an SU(8) hidden gauge symmetry and five Abelian factors. The…
We give a detailed description of the model construction procedures about our new approach to the family structure of the standard model. SM-like chiral fermion spectra, largely "derivable" from the gauge anomaly constraints, are formulated…
We explore the possibility that the observed baryon asymmetry of the universe is the result of an earlier phase transition in which an extended gauge sector breaks down into the $SU(3)_C \times SU(2)_L \times U(1)_Y$ of the Standard Model.…