相关论文: Phenomenology with F-theory SU(5)
The significant heavy threshold effect is found in the supersymmetric SU(5) model with two adjoint scalars, one of which is interpreted as a massive string mode decoupled from the lower-energy particle spectra. This threshold related with…
We construct a three family flipped SU(5) model from the heterotic string theory compactified on the $\Z_{12-I}$ orbifold with one Wilson line. The gauge group is $\rm SU(5)\times U(1)_X\times U(1)^2\times[SU(2)\times SO(10)\times…
An explicit SUSY SU(12) unification model with three light chiral families is presented which avoids any external flavor symmetries. The hierarchy of quark and lepton masses and mixings is explained by higher dimensional Yukawa interactions…
In F-theory GUT constructions Yukawa couplings necessarily take place at the intersection of three matter curves. For generic geometric configurations this gives rise to problematic Yukawa couplings unable to reproduce the observed…
SU(5) $\otimes$ SU(5) provides a minimal grand unification scheme for fermions and gauge forces if there are vector-like quarks and leptons in nature. We explore the gauge coupling unification in a non-supersymmetric model of this type, and…
We explore the gauge coupling relations and the unification scale in F-theory SU(5) GUT broken down to the Standard Model by an internal U(1)Y gauge flux. We consider variants with exotic matter representations which may appear in these…
The observed Standard Model (SM) quark/lepton mass hierarchies and the Cabibbo-Kobayashi-Maskawa (CKM) mixing pattern are described in an ${\rm SU}(8)$ theory through its realistic symmetry breaking pattern with three intermediate stages,…
We construct phenomenological quark-lepton mass matrices based on S$_3$ permutation symmetry in a manner fully compatible with SU(5) grand unification. The Higgs particles we need are {\bf 5}, {\bf 45} and their conjugates. The model gives…
We consider a flavoured $B-L$ gauge symmetry under which only the third generation fermions are charged. Such a symmetry can survive at low energies (~TeV) while still allowing for two superheavy right-handed neutrinos, consistent with…
The non-supersymmetric SU(5) model can accommodate heavy neutrinos and gauge coupling unification when augmented with an adjoint fermionic multiplet 24_F. Among the most important phenomenological implications of the model is the prediction…
We study the textures of SM fermion mass matrices and their mixings in a supersymmetric adjoint SU(5) Grand Unified Theory with modular $S_4$ being the horizontal symmetry. The Yukawa entries of both quarks and leptons are expressed by…
We propose a tri-hypercharge (TH) embedding of the Standard Model (SM) in which a separate gauged weak hypercharge is associated with each fermion family. In this way, every quark and lepton multiplet carries unique gauge quantum numbers…
Inspired by a recently proposed GUT model based on the trinification ($\mathrm{SU}(3)^3$) gauge group with a global family ($\mathrm{SU}(3)_F$) symmetry, we consider an effective low-energy three Higgs doublet model that may shed light on…
We propose a top hypercharge model with gauge symmetry SU(3)_C x SU(2)_L x U(1)_1 x U(1)_2 where the first two families of the Standard Model (SM) fermions are charged under U(1)_1 while the third family is charged under U(1)_2. The U(1)_1…
In grand unified theories with gauge groups larger than SU(5), the multiplets that contain the known quarks and leptons also contain fermions that are singlets under the Standard Model gauge group. Some of these could be the dark matter of…
The logarithmic running of the gauge couplings alpha_1, alpha_2 and alpha_3, indicates that they may unify at some scale M_GUT ~ 10^16. This is often taken to imply that the standard model gauge group is embedded into some larger simple…
We present phenomenological study of the most minimal realistic $SU(5)$ model that owns its predictivity solely to the gauge symmetry and the representational content. The model is built entirely out of the fields residing in the first five…
We investigate the phenomenology of an extension of the Standard Model (SM) by a non-abelian gauge group $SU(2)_{HS}$ where all SM particles are singlets under this gauge group, and a new scalar representation $\phi$ that is singlet under…
In this paper we discuss $SU(5)^{3}$ with cyclic symmetry as a possible grand unified theory (GUT). The basic idea of such a tri-unification is that there is a separate $SU(5)$ for each fermion family, with the light Higgs doublet(s)…
The phenomenological implications of a low-energy supersymmetry are surveyed, with particular attention given to unification constraints and the role of a large top quark Yukawa couplings. Generic expectations for sparticle mass spectra are…