Related papers: Lepton Spectra from e^+ e^- \to W^+ W^- in the BES…
We briefly discuss two possible manifestations of the lepton number violating reaction $e^-e^- \to W_i^-W_j^{(*)-}$, which probes the masses and mixings of heavy Majorana neutrinos, at the Next Linear Collider(NLC). Cross sections for this…
We show that the accumulated LEP-II data taken at $\sqrt{s} =$ 130 to 206 GeV can establish more restrictive bounds on doubly charged bileptons couplings and masses than any other experiment so far. We also analyze the discovery potential…
It is shown that in reaction \gamma\gamma\to\ell^+\ell^-+\nu's at \sqrt{s}>200 GeV with polarized photons, large and well observable differences arise in the distribution of positive and negative charged leptons (\ell=\mu^\pm, e^\pm),…
A search for selectron, smuon and stau pair production is performed with the data collected by the ALEPH detector at LEP at centre-of-mass energies up to 209 GeV. The numbers of candidate events are consistent with the background predicted…
Cross-sections for hadronic, b-bbar and lepton pair final states in e+e- collisions at sqrt(s) = 183 GeV, measured with the OPAL detector at LEP, are presented and compared with the predictions of the Standard Model. Forward-backward…
The general analysis of lepton polarization asymmetries in rare B -> K^* l^+ l^- decay is investigated. Using the most general, model independent effective Hamiltonian, the general expressions of the longitudinal, normal and transversal…
Recent investigations of final state interactions of W+W- events in e+e- collisions up to center of mass energies sqrt{S}=189GeV at LEP2 are reviewed. The data were used to look for color reconnection and Bose-Einstein correlations between…
In 1997 each LEP experiment collected approximately $55 {pb}^{-1}$ of data at a center-of-mass energy of 183 GeV. These data yield a sample of candidate $e^+e^- \to W^+W^-$ events from which the mass of the W boson, M_W, is measured. The…
In $e^+ e^-$ collisions, electromagnetic effects caused by large charge density bunches modify the effective acceptance of the luminometer system of the experiments. These effects consequently bias the luminosity measurement from the rate…
The existence of a strongly interacting sector responsible for the electroweak symmetry breaking is assumed. As a consequence vector and axial-vector bound states may be formed. These resonances mix with the Standard Model gauge bosons and…
Several schemes to introduce finite width effects to reactions involving unstable elementary particles are given and the differences between them are investigated. The effects of the different schemes is investigated numerically for $W$…
We study the sensitivity to doubly charged Higgs bosons, $\Delta^{--}$, in the process $e^-\gamma\to e^+ \mu^-\mu^-$ for centre of mass energies appropriate to future high energy $e^+e^-$ collider proposals. For $M_\Delta <…
Using $e^+e^-$ collision data collected with the BESIII detector at seven energy points ranging from 3.68 to 3.71 GeV and corresponding to an integrated luminosity of $652.1~{\rm pb^{-1}}$, we present an energy-dependent measurement of the…
We study the process e^+e^- --> W^+W^- to probe low-scale gravity at high energy linear colliders. A characteristic signature of extra-dimensions models is the forward-backward asymmetry due to the interference of spin-2 graviton and spin-1…
The energy spectrum of the lepton(s) in e^+e^- --> tt-bar --> l^{+-} ...../l^+l^-..... at next linear colliders (NLC) is studied for arbitrary longitudinal beam polarizations as a possible test of new physics in top-quark couplings. The…
Model independent constraints on the mass of extra neutral gauge bosons and their couplings to charged leptons are given for LEP~II and a 500\,GeV $e^+e^-$ collider. Analytical exclusion limits are derived in the Born approximation. The…
We consider the prospects for detecting effects due to the Higgs exchange diagram in high energy mu^+ mu^-$, e^+ e^-, and tau^+ tau^- collisions producing a pair of W bosons. The processes l^+l^- -> W^+W^- (with l=mu,e,tau) are analyzed,…
Scalar partners of quarks and leptons, predicted in supersymmetric models, are searched for in e^+e^- collisions at centre-of-mass energies between 192GeV and 209GeV at LEP. No evidence for any such particle is found in a data sample of 450…
A study of W+W- events accompanied by hard photon radiation produced in e+e- collisions at LEP is presented. Events consistent with two on-shell W-bosons and an isolated photon are selected from 183pb^-1 of data recorded at root{s}=189GeV.…
We study polarized $e^-e^-$ scattering into $\WW$, $\WZ$ and $\ZZ$ final states within the framework of the standard model of electroweak interactions. These mechanisms for producing pairs of weak gauge bosons are potential backgrounds to…