Related papers: Generation mixing phenomena for leptons in $e^+e^-…
If a contact interaction type correction to a Standard Model process is observed, studying its detailed properties can provide information on the fundamental physics responsible for it. Assuming that such a correction has been observed in…
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…
We explore the effects of neutrino and electron mixing with exotic heavy leptons in the process e^+e^-\to W^+W^- within E_6 models. We examine the possibility of uniquely distinguishing and identifying such effects of heavy neutral lepton…
We discuss various experimental tests of the left-right symmetric model possible to perform in the next generation linear colliders. We consider processes which provide sensitive probes of the basic ingredients of the model: right-handed…
Cross-sections and angular distributions for hadronic and lepton pair final states in e+e- collisions at a centre-of-mass energy near 189 GeV, measured with the OPAL detector at LEP, are presented and compared with the predictions of the…
In these lecture notes we present mechanisms for the generation of Majorana neutrino masses and lepton mixing. We consider simple extensions of the Standard Model. Apart from a section about radiative mass generation, we put special…
Recently it was shown that, in the framework of superstring inspired $\E$ models, the presence of generation dependent discrete symmetries allows us to construct a phenomenologically viable class of models in which the three generations of…
Using renormalization group techniques, we examine several interesting relations among masses and mixing angles of quarks and leptons in the Standard Model. We extend the analysis to the minimal supersymmetric extension to determine its…
We analyze the prospects of measuring the parity of Higgs particles in the Standard Model and its supersymmetric extensions. Higgs decays are discussed in this context as well as production processes including, in particular, the fusion of…
Some models for the lepton sector, based on seesaw extensions of the Standard Model, are discussed in which the mu-tau interchange symmetry is realized in various ways. The symmetries defining such models and their characteristic…
The process of top-quark pair production at future high-energy $e^+ e^-$ linear colliders has been investigated as a possible test of physics beyond the Standard Model. Non-standard interactions have been assumed both for the production and…
We consider the production and decay of selectrons and charginos in $e^-e^-$ collisions. The advantage over usual $e^+e^-$ collisions is the very low level of standard model backgrounds which should make the discovery of selectrons or…
A data sample corresponding to an integrated luminosity of 232pb^-1 was collected in 1997 and 1998 by the L3 experiment at LEP in e+e- collisions at centre-of-mass energies between 181.7GeV and 188.7GeV. Pair production of fermions and…
Recently, significant enhancements of $e^{+} e^{-}$ pair production at very low transverse momentum ($p_{T} < 0.15$ GeV/c) were observed by the STAR collaboration in peripheral hadronic A+A collisions. This excesses can not be described by…
This review illustrates by means of sample reactions the potential of a future global e+e- Linear Collider (LC) for precision measurements of Supersymmetric particles with emphasis on recent studies and addressing major research directions.
Lepton flavor violating processes are obtained from the mixing between ordinary leptons and vectorlike SU(2)_L doublet leptons which may originate in E_6. The effects of this lepton mixing are, however, suppressed naturally by the hierarchy…
We investigate the potentialities offered by the study of lepton-pair production in ultraperipheral collisions at a fixed-target experiment using the proton and ion LHC beams. In these collisions, exclusive or semi-exclusive lepton-pair…
The experimental potential of e+e- Linear Colliders to explore the properties of supersymmetric particles is reviewed. High precision measurements of masses, spin-parity, gauge quantum numbers, couplings and mixings, production and decay…
Hadron production and lepton-pair production in e+e- collisions are studied with data collected with the L3 detector at LEP at centre-of-mass energies sqrt{s}=192-208GeV. Using a total integrated luminosity of 453/pb, 36057 hadronic events…
We delineate the techniques and prospects for using Higgs pair production in $e^+e^-$ or $\mu^+\mu^-$ collisions to probe GUT-scale boundary conditions in the minimal supersymmetric standard model.