Related papers: Constraints on Extended Neutral Gauge Structures
We review constraints on additional Z' bosons predicted in supersymmetric (SUSY) E_6 models from electroweak experiments - Z-pole experiments, mW measurements and the low-energy neutral current (LENC) experiments. Four representative models…
The constraints of fixed-target DIS data in fits of parton distributions including QCD corrections to next-to-next-to leading order are studied. We point out a potential problem in the analysis of the NMC data which can lead to…
We consider the extension of the standard model with an arbitrary number of U(1) gauge fields coupled to baryon-minus-lepton number and/or hypercharge. Under the assumption that A^b_FB from the LEP1 experiment is an unlucky fluctuation, we…
The ATLAS collaboration recently recorded possible excess in the di--boson production at the di--boson invariant mass at around 2 TeV. Such an excess may be produced if there exist additional $Z^\prime$ and/or $W^\prime$ at that scale. We…
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,…
We examine direct limits on masses of the extra neutral gauge bosons in the SU(4)_L \times U(1)_X model with a little Higgs mechanism confronted with the LHC data, especially by embedding anomaly-free set of fermions. There exist two extra…
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…
Precise measurements of the mass and width of the W boson are sensitive to radiative corrections and can be used to place limits on new physics beyond the Standard Model and validate the consistency of the model. In particular, the W boson…
Model independent constraints on the mass of an extra neutral gauge boson and its couplings to charged leptons are given for the $e^-e^-$ option of a future linear collider. Analytic exclusion limits are derived in the Born approximation.…
The unified compositeness of leptons, quarks and Higgs bosons is proposed as a possible scenario for New Physics beyond the Standard Model. The following topics of the scenario are briefly discussed: - Chiral gauge exceptional symmetry E_6…
We study the framework of $U(1)_X$ models with kinetic mixing and/or mass mixing terms. We give general and exact analytic formulas and derive limits on a variety of $U(1)_X$ models that induce new physics contributions to neutrino-electron…
A review of the Higgs and neutralino sectors of supersymmetric models is presented. This includes the upper limit on the mass of the lightest Higgs boson in the Minimal Supersymmetric Standard Model, as well as models based on the Standard…
We calculate the tree-level expressions for the electroweak precision observables in the SU(5)/SO(5) littlest Higgs model. The source for these corrections are the exchange of heavy gauge bosons, explicit corrections due to non-linear…
We revisit the constraints on the properties of right handed neutrinos from the requirement to explain the observed light neutrino oscillation data in the type-I seesaw model. We use well-known relations to show that there is in general no…
We study the constraints that electroweak precision data can impose, after the discovery of the Higgs boson by the LHC, on neutrinophilic two-Higgs-doublet models which comprise one extra $SU(2)\times U(1)$ doublet and a new symmetry,…
Precision electroweak data are generally believed to constrain the Higgs boson mass to lie below approximately 190 GeV at 95% confidence level. The standard Higgs model is, however, trivial and can only be an effective field theory valid…
We study mass bounds of the $W_R$ gauge boson in generic left-right symmetric models. Assuming that the gauge bosons couple universally to quarks and leptons, we allow different gauge couplings $g_R \ne g_L$ and mass mixing, $V_{CKM}^L \ne…
New results from the CDF Collaboration on the invariant mass distribution of dijet events observed at the Tevatron are used to constrain the masses and couplings of new gauge bosons ($W'$ and $Z'$) as well as fundamental diquarks which can…
Based on Ref.[1], we study a composite Z' model which effectively induces the Stueckelberg model in low energy. It turns out that the mass of the composite Z' boson contains the Stueckelberg mass term in sharp contrast to the conventional…
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…