The Neutrino Oscillation MAgnetic Detector, or NOMAD, was an experiment designed to search for neutrino oscillations and to carry out a range of other particle physics measurements. Located at CERN (the European Laboratory for Particle Physics) on the Franco-Swiss border outside Geneva, it was a collaborative effort of 21 university departments and research institutes from 8 countries. About 160 physicists were involved, either full- or part-time, on the project.
Every 14s, 1013 muon neutrinos coming from the CERN SPS go through the 3 ton target of the NOMAD detector. At each burst only one or two neutrino interact. Despite this low rate NOMAD registered up to 500,000 neutrino interactions per year. The physicists search among these interactions to find ones due to not to muon neutrinos but to tau-neutrino.
This discovery would confirm the neutrino oscillation hypothesis : this fundamental phenomena implies that neutrinos are massive particles which would contribute to the hidden mass of the Universe. Moreover, the standard model of particle physics does not predict any masses for neutrino and therefore neutrino oscillation would mean an extension of this model.
Finally, in NOMAD if a muon neutrino - tau neutrino
is seen, this will lead to the first direct detection of the tau
(up to now it has only been indirectly detected via the presence of the
If no tau neutrino is seen, NOMAD will have contributed to the
the oscillation parameters as already done by many other experiments
these last years. Moreover, thanks to its intrinsic characteristics,
NOMAD will have improved previous studies made by various experiments
(CDHS, CHARM and
bubble chamber experiments) on neutrino interactions.
NOMAD took physics data from 1995 to 1998, accumulating well in excess of 1 million neutrino interactions. Analysis of this data is continuing.