Related papers: Electroweak and Dark Matter Constraints on a Z' in…
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'…
We consider dark matter in a minimal extension of the Standard Model (SM) which breaks electroweak symmetry dynamically and leads to a complete unification of the SM and technicolor coupling constants. The unification scale is determined to…
In the framework of an nonuniversal $U(1)'$ extension of the standard model, we propose an scalar candidate for cold dark matter which exhibits interactions with ordinary matter through Higgs and gauge bosons. Using limits from low energy…
Our contribution sets out to investigate the phenomenology of a gauge model based on an $SU_{L}(2) \times U_{R}(1)_{J} \times U(1)_{K}$-symmetry group. The model can accommodate in its distinct phases - by virtue of different…
We tested several models in which the Standard Model (SM) gauge group is extended by an additional U(1) gauge symmetry, against available electroweak precision data to impose limits on the mass of the neutral Z' boson, M_Z', predicted in…
Hidden sectors are ubiquitous in supergravity theories, in strings and in branes. Well motivated models such as the Stueckelberg hidden sector model could provide a candidate for dark matter. In such models, the hidden sector communicates…
We consider a recent proposal by Dimopoulos and Kaplan to embed the electroweak SU(2)_L X U(1)_Y into a larger group SU(3)_W X SU(2) X U(1) at a scale above a TeV. This idea is motivated by the prediction for the weak mixing angle sin^2…
The current generation of Dark Matter Direct Detection Experiments has ruled out a large region of parameter space for dark matter, particularly in the ($10 - 1000$) GeV mass range. However, due to very low event rates, searching for dark…
Several constructions, of stringy origins or not, generate abelian gauge extensions of the Standard Model (SM). Even if the particles of the SM are not charged under this extra $U'(1)$, one cannot avoid the presence of a kinetic mixing…
TeV-scale dark matter is well motivated by notions of naturalness as the new physics threshold is expected to emerge in the TeV regime. We extend the Standard Model by adding an arbitrary SU(2) dark matter multiplet in non-chiral…
The discovery of a 125 GeV Higgs boson and rising lower bounds on the masses of superpartners have lead to concerns that supersymmetric models are now fine tuned. Large stop masses, required for a 125 GeV Higgs, feed into the electroweak…
Motivated by the recent PAMELA and ATIC data, one is led to a scenario with heavy vector-like dark matter in association with a hidden $U(1)_X$ sector below GeV scale. Realizing this idea in the context of gauge mediated supersymmetry…
Z' gauge bosons arise in many particle physics models as mediators between the dark and visible sectors. We exploit dark matter complementarity and derive stringent and robust collider, direct and indirect constraints, as well as limits…
We compute the leading corrections to the properties of W and Z bosons induced at the one-loop level in the SU(5)/SO(5) Littlest Higgs model with T parity, and perform a global fit to precision electroweak data to determine the constraints…
We revisit the Standard Model fit to electroweak precision observables using the latest data and the Particle Data Group value of the mass of the W boson. This analysis is repeated for the value reported by CDF. The constraints on the…
We investigate a so-called 331 extension of the Standard Model gauge sector which accommodates neutrino masses and where the lightest of the new neutral fermions in the theory is a viable particle dark matter candidate. In this model,…
The study of electroweak boson pair production provides a powerful test of the spontaneously broken gauge symmetry of the Standard Model (SM) and can be used to search for new phenomena beyond the SM. Extra neutral vector bosons $Z'$…
A global analysis is performed using the latest data from LEP and SLC. Constraints on the electroweak universal parameters ($S,T,U$) and on the masses of the top quark and Higgs boson within the Standard Model (SM) are investigated. The…
In a truly model-independent approach, we reexamine a minimal extension of the Standard Model (SM) through the introduction of an additional $U(1)$ symmetry leading to a new neutral gauge boson ($Z'$), allowing its kinetic mixing with the…
We update our previous work on an analysis of the electroweak data by including new and partly preliminary data available up to the 1996 summer conferences. The new results on the Z partial decay widths into b and c hadrons now offer a…