Related papers: Tests of Low Scale Quantum Gravity in $e^-e^-$ and…
Standard model gauge bosons propagating in two universal extra dimensions give rise to heavy spin-1 and spin-0 particles. The lightest of these, carrying Kaluza-Klein numbers (1,0), may be produced only in pairs at colliders, whereas the…
In the framework of quantum gravity propagating in large extra dimensions, the effects of virtual Kaluza-Klein gravitons on the imaginary part of the amplitude of the process e+ e- --> f f-bar are analyzed at the Z-pole. Notably, the…
Grand unified theories (GUTs) and extra dimensions are potential ingredients of the new physics that may resolve various outstanding problems of the Standard Model. If the inverse size of (one of) the extra dimension(s) is smaller than the…
If the Standard Model is embedded in a left-right symmetric gauge theory at the TeV scale, the pair production of light W-bosons in e^+e^- collisions, e^+e^- -> W^+W^-, will be affected by mixings in the gauge and neutrino sectors, and by…
Characteristic features of processes mediated by gauge bosons are discussed in the framework of theories with large extra dimensions. It is shown that if gauge bosons propagate in the bulk, then there arises a destructive interference not…
We study the processes \gamma \e -> \gamma \e and \gamma \gamma -> \gamma \gamma, in the context of the proposal for Weak Scale Quantum Gravity (WSQG) with large extra dimensions. With an ultraviolet cutoff $M_S \sim 1$ TeV for the…
The $ZZ\gamma$ triple neutral gauge couplings are absent in the Standard Model (SM) at the tree level. They receive no contributions from dimension-6 effective operators, but can arise from effective operators of dimension-8. We study the…
This work presents a general formalism to analyze a generic bulk scalar field in a multiple warped extra-dimensional model with arbitrary number of extra dimensions. The Kaluza-Klein mass modes along with the self-interaction couplings are…
We present methods to measure the beam polarizations and the luminosity of $\gamma \gamma$ colliders at TeV energy scale. The beam polarizations of a $\gamma \gamma$ collider can easily be monitored by comparing the numbers of events of the…
We investigate the charged scalar lepton production processes $\gamma\gamma\to{\widetilde{\ell}}^{+}{\widetilde{\ell}}^{-}$ at high energy $\gamma\gamma$ colliders in the framework of the minimal supersymmetric standard model (MSSM). Here…
We study the sensitivity reach of $0.5-2$ TeV $e^+ e^-$ linear colliders in the context of the ADD model, in which gravity becomes strong at TeV scale. We include the real emission channel $e^+ e^- \to \gamma G$, as well as the…
If there is no the Standard Model Higgs boson, the interaction among the gauge bosons becomes strong at high energies (~ 1TeV). The effects of strong electroweak symmetry breaking could manifest themselves indirectly through the vertices as…
The ability of high energy $e^+e^-$ colliders to indirectly probe the existence of heavy new charged gauge bosons via their exchange in the reaction $e^+e^-\to \nu\bar\nu\gamma$ is investigated. It is shown that examination of the resulting…
Recent theoretical scenarios propose that quantum gravity effects may manifest at LEP energies by means of gravitons that couple to Standard Model particles and propagate into extra space dimensions. These predictions are checked against…
Effects of Kaluza-Klein excited neutral vector bosons ($Z'$ bosons) in the gauge-Higgs unification on $e^+e^- \to \bar{q}q, \ell^+\ell^-$ cross sections are studied, particularly in future $e^+ e^-$ collider experiments with polarized…
Polarization of both electron and positron beams at a future linear collider (LC) allows for the measurement of transverse polarization asymmetries. These asymmetries have been shown to be particularly sensitive to graviton or other spin-2,…
We consider the possibility of gauge bosons living in the recently proposed five-dimensional theory with localized gravity. We study the mass spectrum of the Kaluza-Klein (KK) excitations of the gauge fields and calculate their couplings to…
Lepton number violation may arise via the spontaneous breakdown of a global symmetry. In extra dimensions, spontaneous lepton number violation in the bulk implies the existence of a Goldstone boson, the majoron J^(0), as well as an…
We propose a new way to hide extra dimensions without invoking branes, based on Lorentz-violating tensor fields with expectation values along the extra directions. We investigate the case of a single vector ``aether'' field on a compact…
Theories with extra dimensions of inverse TeV size (or larger) predict a multitude of signals which can be searched for at present and future colliders. In this paper, we review the different phenomenological signatures of a particular…