Related papers: LEP $e^{+}\,e^{-}\,\rightarrow\,\mu^{+}\, \mu^{-}\…
The $e^{+}\,e^{-}\,\rightarrow\,l^{+}\, \l^{-}\,\gamma\,\gamma$ anomalous events, regis\-te\-red at $L3$ de\-tec\-tor at $e^+ e^-$ $CERN-LEP$ collider have been analysed. It has been shown that the interpretation of such events as a…
The hypothetic R--resonance production (anomalous "$l\bar l\gamma\gamma$" events at LEP) with 60 GeV mass at FNAL hadron collider has been considered. The cross-section of this R-resonance production with the consequent decay $R \to…
A summary of results obtained from e^+e^- annihilations at LEP is given. The precision measurements around the Z resonance, the results from charged gauge boson production and searches for new particles are reviewed. Particular emphasis is…
In this note, I will review the opportunities offered by the hint of a new resonance observed at LHC for future e+e- TeV linear collider (LC) projects. This discussion is mainly influenced by two specific scenarios of physics which assume…
In this manuscript, I give a short summary on scenarios with new physics scalars that could be investigated at future $e^+e^-$ colliders. I concentrate on cases where at least one of the additional scalar has a mass below 125 GeV, and…
Possible oblique effects from vector particles that are strongly coupled to the known gauge bosons are calculated for the case of final hadronic states produced at future $e^+e^-$ colliders, using a formalism that was recently proposed and…
I give a short summary on scenarios with new physics scalars that could be investigated at future $e^+e^-$ colliders. I concentrate on cases where at least one of the additional scalar has a mass below 125 GeV, and discuss both models where…
Radiative returns to the Z resonance (Zgamma events) provide a method to determine the centre-of-mass energy of the high energy e+e- colliders and already at LEP2. The method is applied for the data collected with the ALEPH detector in 1997…
We consider possible production of heavy leptons via anomalous interactions at future $ep$ colliders (THERA and LHeC), $e^+e^-$ colliders (ILC and CLIC) and $pp$ collider CERN LHC. The production, backgrounds and signatures of heavy leptons…
We present a numerical estimate of the $\gamma^* \gamma^*$ total cross section at LEP and at the designed $e^+e^-$ Next Linear Collider (NLC), based upon the BFKL Pomeron. We find for the linear collider that the event rate is substantial…
Two-photon collisions at the e$^+$e$^-$ colliders allow to investigate the formation and the properties of resonant states in a very clean experimental environment. A remarkable number of new results have been recently obtained giving…
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…
Data from the Large Electron Positron collider (LEP) at CERN on hadron production in gamma-gamma interactions exceed the predictions of the standard model by an order of magnitude at the highest observed transverse momenta in three…
Single- and multi-photon events with missing energy are selected in 619/pb of data collected by the L3 detector at LEP at centre-of-mass energies between 189GeV and 209GeV. The cross sections of the process e^+e^- -> nu nu gamma (gamma) are…
We study the potential for using $e\gamma$\ collisions produced by backscattered laser photons to investigate WW$\gamma$\ couplings. We present results for Next Linear Collider energies of 500 GeV and 1 TeV. We find that where statistics…
Recently, the L3 collaboration has reported the observation of four events in the reactions e+ e- --> L+ L- + (2 Photons), L = e, mu, tau, with the invariant photon pair mass near 60 GeV in a data sample collected in the L3 detector…
Recent theories propose that quantum gravity effects may be observable at LEP energies via gravitons that couple to Standard Model particles and propagate into extra spatial dimensions. The associated production of a graviton and a photon…
We perform a detailed study of the process $e^+e^-\to \mu^+\mu^-\nu_l\bar\nu_l$ including all contributions. The contributions other than from real gauge boson production leads to a rich phenomenology. We explore the use of the process as a…
A recent publication based on ALEPH $\mathrm{e}^+\mathrm{e}^-$ data taken near the Z resonance reports an excess, near 30 GeV, in the di-muon mass spectrum for events containing b quarks. In this paper we measure the di-muon mass spectrum…
Photon colliders (gamma-gamma, gamma-e) are based on backward Compton scattering of laser light off the high energy electrons of linear colliders. Recent study has shown that the gamma-gamma luminosity in the high energy peak can reach…