Unitarity tests at high energies

Consequences of t-channel unitarity for the interaction of real and virtual photons at high energies

We analyze the consequences of t-channel unitarity for photon cross sections and show what assumptions are necessary to allow for the existence of new singularities at Q = 0 for the γp and γγ total cross sections. For virtual photons, such singularities can in general be present, but we show that, apart from the perturbative singularity associated with γ∗γ∗ → qq̄, no new ingredient is needed to ...

Qcd at High Energies

The following topics in perturbative QCD are reviewed: recent theoretical progress in higher-order calculations; soft-gluon resummation for hard-scattering processes at large ET and high x; low-x behaviour of structure functions and recent theoretical results on BFKL dynamics; infrared renormalons and power corrections to perturbative predictions; updated summary of αS measurements. CERN-TH/97-...

Bhabha Scattering at High Energies

A study of the process, e+e---) e+e-7, where at least one electron scatters at a small angle is presented. Calculations of the process to order o3 and cr4 are reviewed and compared with data from the PEP storage ring. An analysis of data from the Mark II detector shows good agreement with the order cx4 calculation for e7 final states. Preliminary results from the ASP detector agree well with th...

Neutrino Scattering at High Energies

The construction of a high energy (∼100 GeV), sign-selected neutrino beam opens exciting opportunities to search for beyond-standard-model physics as well as to make valuable QCDmeasurements. Such a beam can be produced at the Tevatron or, potentially, at the CERN SPS+. The resulting physics would be unique and complementary to the present neutrino program. Here we use neutrino-electron scatter...

Tests of the Electroweak Standard Model at High Energies ( √ s > 50 GeV ) ? Morris