ALEPH experiment

The ALEPH detector was one of four detectors at the LEP storage ring at CERN, who collected data from 1989 to 2000. The name is an acronym for "Apparatus for LEP Physics". Objectives of the experiment, the test of the Standard Model and the search for characteristics of unknown new physics beyond the Standard Model.


The structure is located onion skins around the collision point as with most large detectors at scattering experiments. In this case, three areas can be distinguished:

  • Tracking
  • Calorimetry
  • Myonenmessung

The tracking system has the task to measure the tracks of the particles and, where appropriate, to allow statements about the particle type. The innermost shell is used here the most accurate local measurement using silicon semiconductor elements in the form of a so-called vertex detector. The matter Inappropriate drift chamber ( at ALEPH Inner Track Chamber, ITC, called ) allows now also the track record in the r- φ plane and a pulse measurement and thus a way to determine the particle type. The final element of the toe measurement is followed by another drift chamber ( Time Projection Chamber, TPC) which records three coordinates and contributes on the energy loss of the particle within the chamber for particle identification.

The calorimeter system covers the electromagnetic and hadronic calorimeters that. Depending on the nature of the particles produced measure one or both of the calorimeter energy.

The Myonendetektion takes place in the outermost shell, since muons can generally happen only every particle detectors.