Measurements of the Photon Structure Function at LEP

In this contribution we discuss recent measurements by the LEP experiments on photon structure functions.Comment: 3 pages, 5 figures, talk presented at the International Europhysics Conference on High Energy Physics EPS, July 17th-23rd 2003, Aachen, German

Two Photon Physics at Future Linear Colliders

Prospects for QCD studies in two-photon interactions at a future linear e+e- and gamma-gamma collider are discussed.Comment: 8 pages, 5 figures To be published in the proceedings of Photon 2000, Ambelside, England, 26-31 August 200

Physics at a gamma gamma, e gamma and e-e- Option for a Linear Collider

This report presents a review of the studies made in the working group on gamma gamma and e gamma physics" of the ECFA/DESY workshop on linear collider physics. It reports on several new physics studies, in particular s-channel Higgs production. A summary of R&D activities for the interaction region is presented. The merits of e-e- collisions are briefly recalled.Comment: 10 pages, 20 figures. Proceedings of the ECFA/DESY study on Physics and Detectors at a Linear Collider. The wor reported in this talk was done by members of the gamma gamma and e gamma physics working group of the Extended ECFA/DESY Stud

Total gamma-gamma and gamma*-gamma* Cross Sections Measured at LEP

Recent results on total cross-section measurements in gamma-gamma and gamma*-gamma* collisions at LEP are reported. Phenomenological fits to the data are presented.Comment: 4 pages, 4 figures To be published in the proceedings of Diffraction 2000, Cetraro, Italy, September 2 - 7, 200

Future physics with polarized ep-colliders

We discuss some of the physics opportunities at polarized ep-colliders. Recent studies for polarized ep-colliders include HERA, EIC and THERA.Comment: 7 pages, 6 figures, Invited talk presented at the ``International Workshop on the Spin Structure of the Proton and Polarized Collider Physics'', ECT, Trento, Italy, July 23-28, 200

Discussion session on diffractive Higgs production

This note summarizes the discussion session on diffractive Higgs production at the DIS2002 workshop.Comment: Discussion session at DIS 2002, Cracow, May 200

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

Delta G(x) from high p_t hadrons in DIS at a polarised HERA

We investigate the possibility to identify photon-gluon fusion (PGF) events in polarised deep inelastic ep scattering, assuming the kinematics of the HERA collider, by a pair of charged high p_t particles. In a Monte Carlo study we find possible selection criteria and show the expected measurable asymmetries. We discuss the sensitivity to $\Delta G(x)$ and compare the result to the one obtained using di-jets to tag PGF events.Comment: 8 pages, 5 figures, Contributed paper to the Proceedings of the Workshop on Physics at HERA with Polarized Protons and Electron