General

As mentioned in section i.1.4.1, there are three logical units in the CMS simulation software which have common initialisation and termination stages:

• CMGEO -- creation of GEANT-RZ file which contains as GEANT structures all detector constants including geometry, materials, tracking media, magnetic field and sub-detector parameters. The UTIL- and DETC-packages (see below) provide utilities for this operation.
• CMSIM -- the CMS detector simulation program which uses the GEANT structures provided by CMGEO to
  • read or generate KINE structures for a given event
  • track all particles from this event through the detector elements
  • simulate detector hits
  • convert detector hits into digitisation (i.e., the expected detector response).
• CMREC -- reconstruction of the event, including:
  • reconstruction of hits and showers from digitisation
  • charged track pattern recognition
  • electromagnetic and hadronic shower reconstruction
  •