Determination of the muon Yukawa coupling at high energy e+e- linear colliders

The perspectives for the observation of the rare decay H -> mumu decay and the determination of the muon Yukawa coupling at a TeV-class and at a multi-TeV e+e- linear colliders are discussed. The signal for the decay can be obtained at 0.8 TeV and a first estimate of the coupling derived. A linear collider operating at 3 TeV, with high luminosity, is able to improve the accuracy on this couplings to 4% to 11% for 120 GeV < M_H < 150 GeV.Comment: 3 pages, 2 figures, to appear on the proceedings of the Snowmass 2001 Summer Study, Snowmass CO, June-July 200

Heavy Quark Production at the TESLA Collider and its Sensitivity to the Gluon Content in Photon

Heavy quark production is studied at the high energy linear e^+e^- collider (LC) TESLA both in its nominal and Photon Collider (PC) mode. Leading order cross-sections are calculated for the production of heavy quarks, e^+e^- -> e^+e^- Q\bar{Q}X, at high transverse momenta. The sensitivity of this process to the gluon content in the photon is studied.Comment: 16 pages, Latex, 10 ps figures, uses epsfig.sty. IFT 2001/3

Direct Searches of New Physics at CLIC

The multi-TeV e+e- collider CLIC may allow for the direct study of new neutral gauge bosons or Kaluza-Klein states in the TeV range. We discuss some of the experimental aspects for the study of such resonances. Further we discuss briefly the effects of soft branes in scenarios with Large Extra Dimensions, and the production of Black Holes at CLIC.Comment: 9 pages, 4 figures, to appear in the proceedings of the LCWS02 Worksho

The polarised gluon density from di-jet events in DIS at a polarised HERA

We present a possible direct measurement of the polarised gluon density $\Delta G(x)$ in LO from di-jet production in polarised deep inelastic ep scattering, assuming the kinematics of the HERA collider. We show the sensitivity to the x-dependence of $\Delta G(x)$ and to the first moment $\int \Delta G(x) dx$ in the range $0.002< x <0.2$, assuming the electron and proton beam of HERA being polarised to 70% and an integrated luminosity of at least 200 pb$^{-1}$. We include in our study hadronisation and higher order effects, as well as realistic detector smearing and acceptance. We find that the statistical and systematic uncertainties are small enough to distinguish between different parametrizations for $\Delta G(x)$, which all are in accordance with present data. We stress that at HERA an x-range could be measured, that is not accessible to any other present or proposed experiment.Comment: 15 pages, 9 figures, Contributed paper to the Proceedings of the Workshop on Physics at HERA with Polarized Protons and Electron

Graviton Production at CLIC

Direct production of Kaluza-Klein states in the TeV range is studied for the experimental environment at the multi-TeV $e^+e^-$ collider CLIC. The sensitivity of such data to model parameters is discussed for the Randall-Sundrum(RS) and TeV scale extra dimensional models.Comment: 5 pages, 5 figures, to appear on the Proceedings of the Snowmass 2001 Summer Study, Snowmass CO (USA), July 200

The Drell-Hearn-Gerasimov Sum-Rule at Polarized HERA

We discuss the potential of polarized HERA to measure the spin dependent part of the total photoproduction cross-section at large $\sqrt{s_{\gamma p}}$.Comment: 7 pages, LaTeX, 1 figure generated as fig1.tex. To appear in Proc. Workshop on ``Physics with Polarized Protons at HERA'

Environmental impact of timber frame walls

Timber frame walls are increasingly applied nowadays due to the stringent energy performance requirements of buildings. The aim of this study was to investigate the environmental impact of this type of construction. Therefore, a cradle to gate analysis was used. The study consists of three consecutive steps. First the impact of the constituting materials was studied. The results show e.g. that the environmental impact of LVL studs is significantly larger than that of SLS studs or I-joists. Based on these results on material level, in the second stage three timber frame walls were designed and evaluated. All walls had the same thermal performance. When comparing the results, it was noted that the environmental impact of the wall with the highest impact is three times larger than that of the wall with the lowest impact. Finally, the study also looked at the additional impact of tapes for guaranteeing the air tightness of timber frame constructions and at the impact of fasteners. It could be concluded that the impact of tapes is negligible when looking at the total impact of the wall (less than 1%). The fasteners on the other hand, lead to an increase in environmental impact with almost 20%

Predictions for the γγ\gamma \gamma total cross-section in the TeV region: an update

In this talk we present an update of model predictions for the $\gamma \gamma$ total cross-section in the TeV region. The update includes preliminary results for $\gamma \gamma$ cross-sections using the Bloch-Nordsieck model for the overlap function of the partons in the transverse space, use of the CJLK parametrisation of the photonic parton densities that has recently become available and extension to the higher $\gamma \gamma$ energies relevant to the planned CLIC collider.Comment: Talk presented by A. De Roeck at the International Linear Collider Workshop, Jeju Island, Aug. 26-30,2002. To appear in the proceedings. 10 pages, LaTeX file, requires A4.sty, four figure