In this research, we reviewed how to get the relationship of the neutrino oscillation
probability in the two flavor approximation, and tested the theoretical model of the
oscillation solution. We show that the oscillation probability of neutrino re
lates with
neutrino energy, length of the baseline (the distance between the source and the detector),
mixing angle , and square mass difference
2
2
2
1
2
12 m m m . This research shows that in
order to occur the oscillation of neutrino, it must be at least one of the mass states different
of zero. This means that the relationship 0 2
12 m must be verify. In other words neutrino
must have non zero mass. This result holds a huge physical importance. The first regards
the Standard Model of elementary particles, which considered neutrino massless. The
second regards the OPERA experiment, where neutrino have non zero mass, and cannot
spreading fast equal to the speed of light and so this does not agree with the experience of
OPERA, which found that the neutrino spreading faster than the speed of light in a
vacuum.
