Version francaise


A scientific result is always temporary. It navigates between "certitudes" until a new result come to replace or improve it. This even more true about the neutrino. If you want to look at more complete neutrino physics results, I advise you to look at two Web sites that were among my best references: Last results (31 march 2006):
MINOS experiment has observed 92 events of neutrino-mu interactions, where it was expecting 177+-11. MINOS has thus observed a disappearance effect at 5 sigmas and provide the following value for the square neutrinos masses difference: Dm2 = 3.1 +- 0.6 +- 0.1 10-3 eV2
Have a look at:

In 1998, the main results were the following:

Spin Masse Magnetic spin Cross section on nucleon at 1 GeV
nu_e 1/2 < 2.8 eV < 5.8 10-20 MeV/T around 10-38 cm2
nu_mu 1/2 < 16=70 keV < 4.3 10-20 MeV/T environ 10-38 cm2
nu_tau 1/2 < 18.2 MeV < 3.1 10-17 MeV/T around 10-38 cm2
There are 3 families
of light neutrinos.
The neutrinos have all left helicity
and anti-neutrinos have all right helicity
(but the term "all" can be discussed!)
Neutrinos may be have a non zero mass
Two recent results seem to
indicate neutrinos oscillation:
Other experiments like Chooz,
Chorus or Nomad did not find any evidence for
neutrinos oscillation
but they push further the limits
on the two factors that control neutrinos oscillations: and .

Nota Bene:
The result of an experiment searching for neutrinos oscillation is often represented on a two dimensional graphics where is displayed versus . The first parameter is the difference of the squared masses oif the two types of neutrinos that oscillate in each other (simplified case of a two types neutrino oscillation). The second parameter is the maximal probability that a neutrino oscillates.

Back to main page

Last update: 26/06/1999 :
Didier Verkindt