Theta 13 Reactor Experiments

The Last Mixing Angle

Reactor image    In measuring neutrinos coming from both the atmosphere and the sun, we have learned that neutrinos do possess mass and "oscillate" amongst each other.  The mass splitings between different neutrinos, as well as the mixing parameters, are now being measured with increasing precision.  One of these parameters --theta13, however, remains to be measured.  If this mixing angle is not too small, it may help explain why the universe appears to be made mostly of matter rather than anti-matter.

    So far, the best limits on this mixing angle come from experiments studying neutrinos produced in nuclear reactors.  The next generation of such experiments is now being developed, with efforts taking place around the globe.  The basic scheme is to use two 50 ton detectors filled with liquid scintillator to study the anti-neutrino reaction on hydrogen.  The process produces a neutron, which is later captured.  This very technique was how neutrinos were first discovered.

    Current efforts hope to push the limit on theta13 by about one order of magnitude better than previous measurements. 


Theta13 Exotica

Documents & Papers of Interest:

The White Paper (A proposal for measuring Theta13 with Reactors)
Paper on the Chooz Measurement
Three Neutrino Mixing (Maltoni Paper)
Reactor and Long Baseline Complimentarity

Notes on Backgrounds

Proposed Sites:

Theta13 Midwest Reactor Group (U.S.)
Diablo Caynon (U.S.)
Daya Bay (China)
Angra Reactor (Brazil)
Double-CHOOZ Project (France)
KR2DET (Russia)
KASKA (Japan)