Discoveries in Electron–Positron Collisions

Abstract

The electron is a point-like particle (differently from the proton, which is made of quarks) and e ⁺ e ⁻ colliders are particularly suited for converting energy in mass. e ⁺ e ⁻ collisions provided the first experimental indication of the quark color quantum number, the discovery of the charm quark and the τ lepton. Finally, high-precision measurements of the electroweak theory parameters and a thorough verification of the Standard Model was performed by the four LEP experiments at CERN and by SLD at Stanford. The problems presented here mainly treat event rates, beam attenuation luminosity of e ⁺ e ⁻ colliders. All the LEP experiments (ALEPH, DELPHI, L3 and OPAL) and SLD were huge and complex experimental apparata with many subdetectors. Detectors provide information in the form of electric signals, which must be processed by a series of electronic components which were described in Supplement 8.1. The following electronic logic and the fundamental aspects of the trigger of an experiment are described in Supplement 9.1.