We review the one-loop corrections to the partial decay width of sbottomquark into a top quark and a chargino for the parameter space relevant to the TESLA ee linear collider. We present the results available in the literature for the QCD and the Yukawa coupling corrections in a unified framework. In this way a direct comparison of the size of the various corrections is possible. Talk presented...

Beam polarization at e+–e− linear colliders will be a powerful tool for high precision analyses. Often it is assumed that the full information from polarization effects is provided by polarization of the electron beam and no further information can be obtained by the simultaneous polarization of the positrons. In this paper we point out the advantages of polarizing both beams, and summarize the...

I discuss the calculation of cross sections for processes with six and eight fermions in the final state, contributing to single-top production and associated top-Higgs production at a linear collider. I describe the schemes for the treatment of finite decay widths implemented in the matrix element generator O’Mega and give a numerical comparison for single-top production. In the case of single...

The advantages and possibilities of fiber technology for the detection of particles in 500 GeV ee reactions are considered. It is suggested to build a fast trigger which could be used also for intermediate tracking. A fiber preshower in front of the electromagnetic calorimeter would allow to identify electrons and photons with a space precision better than 100 μm. INTRODUCTION ee reactions have...

We study opportunities for future high-precision experiments in kaon physics using a high-intensity proton driver, which could be part of the front-end of a muon storage ring complex. We discuss in particular the rare decays KL → π0νν̄, K+ → π+νν̄, KL → π0e+e−, and lepton-flavour violating modes such as KL → μe and K → πμe. The outstanding physics potential and longterm interest of these modes is...

Using muons as a source of neutrinos can be traced back to 25 years ago but it is with the recent studies on muon colliders that this idea came back to the front of the stage. It was specifically discussed in a FNAL workshop (1997), a BNL workshop (1998) and a study group dedicated to that topic was set up at CERN in 1998. νFact99 appears as the conclusion of this preparatory work and is the fi...

It is shown that at least four massive neutrinos are needed in order to accommodate the evidences in favor of neutrino oscillations found in solar and atmospheric neutrino experiments and in the LSND experiment. Among all four-neutrino schemes, only two, with a mass spectrum composed of two pairs of neutrinos with close masses separated by the “LSND gap” of the order of 1 eV, are compatible wit...

The first Part contains the invited talk titled “Four Ways to TeV Scale” given at the First International Workshop on Linac-Ring Type ep and γp Colliders (9-11 April 1997, Ankara, Turkey). Four known types of colliders, which may give an opportunity to achieve TeV center of mass energies in the near future (10-15 years), are discussed. Parameters of the linac-ring type ep, γp, e-nucleus and γ-n...

We determine the accuracy of various approximations to the O(α) corrections for onshell W-pair production. While an approximation based on the universal corrections arising from initial-state radiation, from the running of α, and from corrections proportional to m2t fails in the Linear-Collider energy range, a high-energy approximation improved by the exact universal corrections is sufficiently...