Related papers: Conformal Standard Model with an extended scalar s…
The gauge-extended U(1)_C \times SU(2)_L \times U(1)_{I_R} \times U(1)_L model has the attractive property of elevating the two major global symmetries of the standard model (baryon number B and lepton number L) to local gauge symmetries.…
Supersymmetric SO(10) Grand Unified Theories with Yukawa unification represent an appealing possibility for physics beyond the Standard Model. However Yukawa unification is made difficult by large threshold corrections to the bottom mass.…
The flavor problem, neutrino physics and the fermion mass hierarchy are important motivations to extend the Standard Model into the TeV scale. A new family non-universal extension is presented with three Higgs doublets, one Higgs singlet…
The $SU(2)_L$ triplet scalar with hypercharge $Y=0$ predicts a positive definite shift in the $W$ mass, w.r.t.~the Standard Model prediction, if it acquires a vacuum expectation value. As this new field cannot couple directly to SM fermions…
The matter content of the Standard Model admits a global symmetry due to the generational structure of the spectrum respected by all interactions except for fermion couplings to the Higgs doublet. This symmetry is identified as the largest…
The Standard Model (SM) of particle physics is a precise model of electroweak interactions, however there is growing tension between the SM and observations (neutrino oscillations, dark matter, dark energy, baryogenesis, among others).…
We perform a global analysis of a vector-like extension of the Standard Model, which also features additional doublet and singlet scalars. The usual Yukawa interactions are forbidden in this setup by an extra U(1) global symmetry and the…
It is well-known that the $SU(5)$ grand unified theory, with the standard model quarks and leptons unified in $\overline{5}$ and $10$ and the electroweak Higgs doublet residing in $5$ dimensional representations, leads to relation,…
We consider an electroweak model based on the gauge symmetry SU(2)_L X U(1)_Y' X U(1)_B-L which has right-handed neutrinos with different exotic B-L quantum numbers. Because of this particular feature we are able to write Yukawa terms, and…
The electroweak symmetry breaking (EWSB) sector of the Standard Model can be far richer and more interesting than the usual single scalar doublet model. We explore scenarios where the EWSB sector is nearly scale invariant and consequently…
The fact that neutrinos are massive suggests that the minimal supersymmetric standard model (MSSM) might be extended in order to include three gauge-singlet neutrino superfields with Yukawa couplings of the type $H_2 L \nu^c$. We propose to…
We desribe in detail a Z_6 orbifold compactification of the heterotic E_8 x E_8 string which leads to the (supersymmetric) standard model gauge group and matter content. The quarks and leptons appear as three 16-plets of SO(10), two of…
In extended Higgs models, a discrete symmetry is needed in the quark sector to avoid tree-level flavor-changing neutral currents. However, this is not necessary the case in the lepton sector. We consider a model in which one Higgs couples…
In this paper, we propose a specific, nontrivial extension of the Standard Model of weak interactions based on the ${SU(2)}_L\times{U(1)}_Y\times{U(1)}_C$ group. Our motivation follows from the identification of the globally conserved…
We propose a supersymmetric extension of the anomaly-free and three families nonuniversal $U(1)$ model, with the inclusion of four Higgs doublets and four Higgs singlets. The quark sector is extended by adding three exotic quark singlets,…
The LHC and other experiments show so far no sign of new physics and long-held beliefs about naturalness should be critically reexamined. We discuss therefore in this paper a model with a combined breaking of conformal and electroweak…
We propose a theoretical justification for the anomalous Higgs couplings without extending the particle content of the Standard Model, but rather assuming different realization of the electroweak symmetry and the representation of the Higgs…
A non-supersymmetric renormalizable $SO(10)$ model, with CP invariant Yukawa sector consisting of Lorentz scalars in $10$ and $\overline{126}$ dimensional representations, is proposed. The elemental Yukawa couplings are real due to CP…
We discuss a supersymmetric extension of the standard model with an extra U(1) gauge symmetry. In this model, the proton stability is guaranteed by the gauge symmetry without invoking R parity. The gauge symmetry breakdown automatically…
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}…