|Up to now, neutrino experiments have been limited to the perimeter of CERNs
Meyrin site, thus to relatively small distances. A recent discovery in Japan, however,
shows that a "change in the nature" of neutrinos - oscillation between two types
of neutrino - could occur if these particles had a long enough time-of-flight (i.e.
trajectory). To confirm that this is really a neutrino oscillation and to investigate the
phenomenon further, a particle beam (of neutrinos) from CERN would be linked to detectors
located far from the Laboratory, and this for the first time in CERNs history.
underground laboratory at Gran Sasso (Italy)
The underground laboratory at Gran Sasso (LNGS), 120 kilometres
from Rome, is one of the facilities belonging to the INFN, the Italian institute for
research into particle physics and nuclear physics. Since its construction at the
beginning of the nineteen-eighties, an impressive series of fundamental physics
experiments has been carried out. Experiments on neutrinos have a prominent place in the
LNGS research programme: for example the neutrinos produced by cosmic rays in the
atmosphere have been studied (c.f. Figure 3 on page 8).
Since they are protected from muons originating from cosmic rays by 1400 metres of rock,
the three great caverns (c.f. Figure 4 on page 9) of the
laboratory are ideal places for experiments looking for weak signals stemming from the
passage of rare particles. In the design phase of LNGS, in 1979, the caverns were oriented
towards Geneva, with a view to possible experiments with long baseline neutrino beams.
Parts of the three underground halls of the LNGS are now ready for new experiments for
detecting and identifying neutrinos produced at CERN and sent to LNGS over a distance of