Related papers: Leptophobic Z' from Superstring Derived Models
The Standard Model (SM) is augmented with a $\mathrm{U}(1)_{B-3L_\mu} $ gauge symmetry spontaneously broken above the TeV scale when an SM-singlet scalar condenses. Scalar leptoquarks $S_{1(3)} = (\overline{\mathbf{3}},\, \mathbf{1}…
We study two-site deconstructions of the $SU(2)_L$ gauge group factor of the SM. Models based on this approach can explain the hierarchies of the quark masses and CKM mixing between third and light families if these fields are localised on…
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…
A leptophobic $Z^\prime$ that does not couple with the Standard Model leptons can evade the stringent bounds from the dilepton-resonance searches. In our earlier paper [T. Arun et al., Search for the $Z'$ boson decaying to a right-handed…
We explore leptogenesis within the E6 inspired U(1) extension of the MSSM in which exact custodial symmetry forbids tree-level flavour-changing transitions and the most dangerous baryon and lepton number violating operators. This…
We use a $U(2)\times U(1)$ horizontal symmetry in order to construct supersymmetric models where the flavor structure of both quarks and leptons is induced naturally. The supersymmetric flavor changing neutral currents problem is solved by…
A new type of gauge extension of the SM is proposed. It is based on a SU(2)xSU(2)xU(1) group with the peculiarity that the gauge bosons of the extra SU(2) do not couple to fermions. This feature relaxes some of the constraints on the masses…
The structure of the quark and lepton masses and mixing angles provides one of the few windows we have on the underlying physics generating the \sm. In an attempt to identify the underlying symmetry group we look for the simplest gauge…
An extension of the Standard Model to the local gauge group SU(3)_c X SU(3)_L X U(1)_X as a family independent model is presented. The mass scales, the gauge boson masses and the masses for the spin 1/2 particles in the model are studied.…
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…
A new supersymmetric gauge model is proposed with particle content chosen only from the 27 and 27* representations of E_6. The gauge symmetry SU(3) X SU(2)_L X SU(2)_R X U(1) is realized at the TeV energy scale and the gauge couplings…
We present the results of a global analysis of a class of models with an extended electroweak gauge group of the form SU(2) x SU(2) x U(1), often denoted as G(221) models, which include as examples the left-right, the lepto-phobic, the…
We investigate a simple theory where Baryon number (B) and Lepton number (L) are local gauge symmetries. In this theory B and L are on the same footing and the anomalies are cancelled by adding a single new fermionic generation. There is an…
We present a model for third-family quark-lepton unification at the TeV scale featuring a composite Higgs sector. The model is based on a variant of the Pati-Salam model, the so-called 4321 model, consisting of the gauge group $SU(4)\times…
We study quark and lepton mass matrix textures in a model containing an additional $U(1)_X$ gauge symmetry with origins in string compactification. The $U(1)_X$ symmetry is broken near the string scale, and we assume that the anomalies are…
We propose a composite grand unified theory to study the anomalies in the semileptonic $B$ decays. We show a simple group containing the custodial and Standard Model gauge symmetries, that can deliver a set of composite pseudo…
We consider six-dimensional supergravity with gauge group $SO(10)\times U(1)_A$, compactified on the orbifold $T^2 / \mathbb{Z}_2$. Three quark-lepton generations arise as zero modes of a bulk $\bf16$-plet due to magnetic flux of the…
Searching for heavy vector bosons $Z^\prime$, predicted in models inspired by Grand Unification Theories, is among the challenging objectives of the LHC. The ATLAS and CMS collaborations have looked for $Z^\prime$ bosons assuming that they…
This is a short review of present and future limits on new neutral gauge bosons, in particular on hadrophilic or leptophobic $Z'$s recently proposed to interpret the observed fluctuations of $\Gamma _{c,b}$ at LEP. Light gauge bosons…
We propose a quark-lepton symmetric Pati-Salam (PS) model based on the gauge group $SU(2)_L \times SU(2)_R \times SU(4)_C$ with an $E_6$-inspired particle spectrum which naturally accommodates a multi-TeV leptoquark gauge boson…