Related papers: Little Z' Models
The discovery of a standard-model-like Higgs at 126 GeV and the absence of squark signals thus far at the LHC both point towards a mini-split spectrum for supersymmetry. Within standard paradigms, it is non-trivial to realize a mini-split…
We make a comprehensive study of the theory and phenomenology of a low energy supersymmetric standard model originating from a string-inspired $E_6$ grand unified gauge group. The Exceptional Supersymmetric Standard Model (ESSM) considered…
We derive the leptonic neutral current in the simplest little Higgs model and compute the contribution of the model to the decay width $Z \to e^+e^-$. Using the precision electroweak data we obtain a strong lower bound $f\geq 5.6$ TeV at…
A special class of supersymmetric U(1) gauge extensions of the standard model was proposed in 2002. It is anomaly-free, has no mu term, and conserves baryon and lepton numbers automatically. It also allows the lightest Higgs boson to have a…
We consider a supersymmetric version of the standard model extended by an additional U(1)_{B-L}. This model can be embedded in an mSUGRA-inspired model where the mass parameters of the scalars and gauginos unify at the scale of grand…
A simple extension of the Standard Model (SM), based on the gauge group $SU(3)_C\otimes SU(3)_L\otimes U(1)_Y$ with $Y$ being the hypercharge, is considered. We show that, by imposing an approximate global $SU(2)_L\times SU(2)_R$ custodial…
We discuss experimental implications of extending the gauge structure of the Standard Model to include an additional U(1) interaction broken at or near the weak scale. We work with the most general, renormalizable Lagrangian for the…
We investigate the phenomenology of 2 Higgs doublet models (2HDMs) with a new $U(1)$ gauge symmetry, $U(1)_X$, by which flavor changing neutral currents are forbidden at tree level. As an important consequence of the spontaneous breaking of…
We analyze various models with an extra U(1) gauge symmetry in addition to the Standard Model (SM) gauge group at low energies, and impose limits on the mass of the neutral Z' boson, M_Z', predicted in all such models, and on the Z-Z'…
The regions in the Minimal Supersymmetric Standard Model with the minimal amount of fine-tuning of electroweak symmetry breaking are presented for general messenger scale. No a priori relations among the soft supersymmetry breaking…
Assuming the existence of a supersymmetric U(1) gauge factor at the TeV energy scale (motivated either by the superstring-inspired E_6 model or low-energy electroweak phenomenology), several important consequences are presented. The…
A possible minimal model of the gauge-Higgs unification based on the higher dimensional spacetime M^4 X (S^1/Z_2) and the bulk gauge symmetry SU(3)_C X SU(3)_W X U(1)_X is constructed in some details. We argue that the Weinberg angle and…
We examine a model with multiple scalar fields to see whether it is possible to reduce the fine- tuning of the SM Higgs mass without introducing low scale top partners. Our approach may be regarded as a generalization of the condition…
Little Higgs models are formulated as effective theories with a cut-off of up to 100 times the electroweak scale. Neutrino masses are then a puzzle, since the usual see-saw mechanism involves a much higher scale that would introduce…
We consider a 6-dimensional supersymmetric SU(6) gauge theory and compactify two extra-dimensions on a multiply-connected manifold with non-trivial topology. The SU(6) is broken down to the Standard Model gauge groups in two steps by an…
The minimum supersymmetric standard model (MSSM) without R-parity through various lepton-number violations is investigated systematically. All kinds of possible mixing in the model are formulated precisely. The remarkable issue that the…
This study is inspired by a scenario, in which the Standard Model, enhanced by an additional dark matter scalar, could be extended up to the Planck scale, while accommodating the low measured value of the Higgs mass. To that end, we study a…
We propose a class of models with gauge mediation of supersymmetry breaking, inspired by simple brane constructions, where R-symmetry is very weakly broken. The gauge sector has an extended N=2 supersymmetry and the two electroweak Higgses…
It has been known that Little Higgs models with T-parity, which can give a dark matter candidate, suffer from the anomalies of given models through the Wess-Zumino-Witten term, which in turn can violate the T-parity. Here we thus introduce…
We consider a supersymmetric version of the recently proposed SU(3) X U(1) extended gauge model. We show that it is possible to have only two Higgs doublets at the SU(2) X U(1) energy scale but they are not those of the minimal…