Single production of excited electrons at future e^-e^+, ep and pp colliders

We analyzed the potential of the LC with $\sqrt{s}=0.5$ TeV, LC$\times$LHC based ep collider with $\sqrt{s}=3.74$ TeV and LHC with $\sqrt{s}=14$ TeV to search for excited electrons through transition magnetic type couplings with gauge bosons. The $e^{\star}\to e\gamma$ signal and corresponding backgrounds are studied in detail.Comment: 11 pages, 11 figures, 3 table

Turkish Comments on "Future Perspectives in HEP"

These comments were prepared during the ICFA Seminar on "Future Persrectives in High Energy Physics" held at CERN (8-11 October 2002) and partially presented at the Panel and General Discussion on Interregional Collaboration for Future Facilities (10 October). Comments include arguments favoring the existence of the fourth SM family and new level of compositness. Then, the possible role of the linac-ring type colliders for future HEP research is discussed emphasizing TeV scale lepton-hadron and photon-hadron colliders. This preprint presents prepared transparencies and some illuminating remarks with corresponding references

A Search for the Fourth SM Family Fermions and E_6 Quarks at μ+μ−\mu ^{+}\mu ^{-} Colliders

The potential of $\mu ^{+}\mu ^{-}$ colliders to investigate the fourth SM family fermions predicted by flavour democracy has been analyzed. It is shown that muon colliders are advantageous for both pair production of fourth family fermions and resonance production of fourth family quarkonia. Also isosinglet quarks production at $\mu ^{+}\mu ^{-}$ colliders has been investigated.Comment: 9 pages, 5 table

Possible Discovery Channel for New Charged Leptons at the LHC

We propose a channel for the possible discovery of new charged leptons at the Large Hadron Collider. The proposed final state contains three same-sign leptons, making this new channel practically back- groundless. The method is illustrated for two different cases: the four-family Standard Model and the Grand Unified Theory based on the E6 gauge group. An example study taking 250 GeV as the charged lepton mass shows that in both models, about 8 signal events can be expected at 14 TeV center-of-mass energy with 1 fb^-1 of integrated luminosity. Although the event yield might not be sufficient for detailed measurements of the charged lepton properties, it would be sufficient to claim discovery through a counting experiment.Comment: 8 pages, 4 figures. v2 update includes an estimate of the backgrounds, consideration of the EW oblique parameters, and minor improvements. v3 update includes detector acceptance and ttbar backgroun