Related papers: Unique Graviton Exchange Signatures at Linear Coll…
The complementarity of $e^+e^-$ and $\gamma \gamma$ colliders to discover and explore new physics beyond the Standard Model(SM) is discussed. After briefly surveying a number of various new physics scenarios we concentrate in detail on…
We analyze the influence of anomalous gauge couplings in the reaction $e^- \: e^- \longrightarrow e^- \: W^- \: \nu_e$ at a 500 GeV linear collider. The limits imposed by this process on deviations from the standard model of electro-weak…
The exclusive gamma-met signal has a small standard model cross-section and is thus a good channel in which to look for signs of new physics. This signature is predicted by models with a superlight gravitino or with large extra spatial…
We consider the production of gravitinos ($\widetilde G$) in association with gluinos ($\tilde g$) or squarks ($\tilde q$) at hadron colliders, including the three main sub-processes: $q \bar q -> \tilde g\widetilde G$, $qg -> \tilde…
The kinematic distributions in two-particle inclusive processes at an e+e- collider arising from standard-model s-channel exchange of a virtual gamma or Z and the interference of the standard-model contribution with contributions from…
We study the possibilities to detect Majorana neutrinos in $e^- \gamma$ colliders for different center of mass energies. We study the $W^- W^- l_j^{+}(l_j^+\equiv e^+ ,\mu^+ ,\tau^+)$ final state which are, due to leptonic number violation,…
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…
We discuss the sensitivity of the processes e+e- to b b(bar), e+e- to t t(bar) and gamma gamma to H to certain residual New Physics interactions affecting the heavy quark and Higgs boson sector. With a linear collider of 500 GeV, one should…
If the gravitino (G) is very light and all the other supersymmetric particles are above threshold, supersymmetry may still be found at colliders, by looking at processes with only gravitinos and ordinary particles in the final state. We…
Numerous non-standard dynamics are described by contact-like effective interactions that can manifest themselves through deviations of the cross sections from the Standard Model predictions. If one such deviation were observed, one should…
We perform a detailed study of the process $e^+e^-\to\gamma\nu_l\bar\nu_l$ and its sensitivity to anomalous gauge boson couplings of the $\gamma WW$ vertex. We concentrate on LEP II energies, $\sqrt{s}=200$ GeV, and energies appropria- te…
A promising direction to find physics beyond the standard model is to look for violation of $L_{e,\mu,\tau}$ conservation. In particular the process $e^- e^- \to \mu^- \mu^-$ with the exchange of a gauge bilepton has a striking signal…
Measurement of the top-Yukawa coupling is important to understand the fermion mass generation mechanism and dynamics of electroweak symmetry breaking. We discuss the top quark anomalous couplings which can be described by higher dimensional…
We consider the scattering amplitudes of the form V_1 V_2 -> V_3 V_4, where V_i=\gamma, Z, W or g(=gluon) are the Standard Model gauge bosons, due to graviton exchange in Kaluza-Klein theories with large extra dimensions. This leads to a…
The effect of anomalous couplings in $\gamma \gamma \to W^+ W^-$ is studied for different energies of the $\gamma \gamma$ mode of the next linear collider. The analysis based on the maximum likelihood method exploits the variables in the…
We study the exchange of energy between gravitational and electromagnetic waves in a Sagnac type geometry, in analogy to an ``optical Weber bar.'' In the presence of a gravitational wave (such as the ones measured by LIGO), we find that it…
The BFKL dynamics can be successfully tested at the future high energy $e^+e^-$ linear collider. The total $\gamma^*\gamma^*$ cross-section is calculated in the Leading Log QCD dipole picture of BFKL dynamics, and compared with the one from…
We consider the possibility of observing deviations from the Standard Model gauge-boson self-couplings at future $e\gamma$ colliders. We concentrate on the process $e^-\gamma \rightarrow \nu W^- Z$, which is particularly sensitive to the…
As any $e^+e^-$ scattering process can be accompanied by a hard photon emission from the initial state radiation, the analysis of the energy spectrum and angular distributions of those photons can be used to search for hard processes with…
We study the sensitivity of a 500 GeV $e^+e^-$ Linear Collider to $CP$ violating anomalous couplings. We find that with 50~fb$^{-1}$, and taking only one non-zero coupling at a time, the process $e^+e^-\to W^+ W^-$ can be used to place the…