Related papers: Model-Independent $Z'$ Limits from Electron-Electr…
We study electron-electron contact-interaction searches in the process e^+e^-\to e^+e^- at a future e^+e^- Linear Collider with both beams longitudinally polarized. We evaluate the model-independent constraints on the coupling constants,…
We study the possible dynamics associated with leptonic charge in future linear colliders. Leptophilic massive vector boson, Z_(l), have been investigated through the process e^(+)e^(-) -> mu^(+)mu^(-). We have shown that ILC and CLIC will…
The littlest Higgs (LH) model predicts the existence of the new gauge bosons $Z'$ and $B'$. We calculate the contributions of these new particles to the processes $e^{+}e^{-}\to\bar{f}f$ with $f=\tau, \mu, b,$ or $c$ and study the…
We study the process $e^- + e^+ \to e^+ + e^+ + e^- + e^-$ for ILC and CLIC energy regimes, in the minimal 3-3-1 model framework. The main contributions, for the production of two bileptons each one decaying into two same-sign leptons, come…
The Abelian $Z'$ boson decay width is calculated in a model-independent approach. The analysis takes into consideration the special relations between the $Z'$ couplings to the Standard model fields proper to the renormalizable theories. The…
Using LEP1, SLD and LEP2 data, for tau lepton production, and data from CDF, D0 and LEP2, for W decays into tau leptons, we set model independent limits on non-standard electromagnetic and weak magnetic moments of the tau lepton. The most…
We discuss electroweak precision constraints on dimension-6 operators in the effective theory beyond the standard model. We identify the combinations of these operators that are constrained by the pole observables (the W and Z masses and…
We investigate the possibility of probing an extra Higgs boson at future linear $e^+ e^-$ colliders. We consider the production process $e^+e^- \to H\nu \bar\nu$, followed by the decay $H \to W^+W^-$, where $H$ is the extra…
General model-independent expressions are developed for the polarized and unpolarized cross-sections for $e^+e^-\to f\bar f$ near the $Z^0$ resonance. The expressions assume only the analyticity of S-matrix elements. Angular dependence is…
We approach the issue of the discovery of new physics at high energies associated with the proposed International Linear Collider in the presence of longitudinal as well as transverse electron and positron beam polarization. We determine…
Model independent expressions for all polarization observables in $\mu+p\to \mu+p$ elastic scattering are obtained, taking into account the lepton mass and including the two-photon exchange contribution. The spin structure of the matrix…
The sensitivity of future $e^+e^-$ colliders to the new physics deriving from a model of strong electroweak symmetry breaking is discussed. The model considered is an effective lagrangian description of Goldstone bosons and of new vector…
We study theoretical and experimental constraints on electroweak theories including a new color-singlet and electrically-neutral gauge boson. We first note that the electric charges of the observed fermions imply that any such Z' boson may…
This paper presents prospects for measuring the model-independent $ZH$ production cross section at the FCC-ee using the recoil-mass method at center-of-mass energies of $240$ GeV and $365$ GeV. Analyses are carried out in the muon,…
We study the incidence of genuine quartic vector boson couplings in the reactions e-e- -> e-e-ZZ, e-\nu ZW, \nu\nu WW. We find that a linear collider operated in the e-e- mode will provide bounds on these couplings which are competitive…
A broad class of supersymmetric extensions of the standard model predict a Z' vector boson whose mass is naturally in the range 250 GeV < M_Z' < 2 TeV. To avoid unacceptably large mixing with the Z, one requires either a discrete tuning of…
By means of a model-independent analysis, we discuss the constraints on anomalous trilinear gauge-boson couplings that can be obtained from the study of electron-positron annihilation into $W$ pairs at LC with \sqrt{s}=0.5 TeV and 1 TeV. We…
Heavy neutral gauge bosons, Z's, are predicted by many theoretical schemes of physics beyond the Standard Model, and intensive searches for their signatures will be performed at present and future high energy colliders. It is quite possible…
An extension of the Zee model involving a light right handed neutrino, nu_R is considered. We update constraints on couplings between the bilepton scalar, the active neutrinos, nu_R and the charged leptons. We find that the most stringent…
A search is performed in proton-proton collisions at sqrt(s) = 8 TeV for exotic particles decaying via WZ to fully leptonic final states with electrons, muons, and neutrinos. The data set corresponds to an integrated luminosity of 19.5…