THE NOMAD EXPERIMENT AT THE CERN SPS

The NOMAD experiment is a short base-line search for v(mu) - v(tau) os cillations in the CERN neutrino beam. The v(tau)'s are searched for th rough their charged current interactions followed by the observation o f the resulting tau(-) through its electronic, muonic or hadronic deca ys. These decays are recognized using kinematical criteria necessitati ng the use of a light target which enables the reconstruction of indiv idual particles produced in the neutrino interactions. This paper desc ribes the various components of the NOMAD detector: the target and muo n drift chambers, the electromagnetic and hadronic calorimeters, the p reshower and transition radiation detectors and the veto and trigger s cintillation counters. The beam and data acquisition system are also d escribed. The quality of the reconstruction and individual particles i s demonstrated through the ability of NOMAD to observe K-s(o)'s, Lambd a(o)'s and pi(0)s. Finally, the observation of tau(-) through its elec tronic decay being one of the most promising channels in the search, t he identification of electrons in NOMAD is discussed. (C) 1998 Elsevie r Science B.V. All rights reserved.