Beta Beams could address the needs of long term neutrino oscillation
experiments. They can produce extremely pure neutrino beams through the decays
of relativistic radioactive ions. The baseline scenario is described, together
with its physics performances. Using a megaton water Cerenkov detector
installed under the Frejus, Beta Beams could improve by a factor 200 the
present limits on \sin^2{2 \thetaot} and discover leptonic CP violating
effects if the CP phase delta would be greater than 30 degree and theta13
greater than 1 degree. These performances can be further improved if a neutrino
SuperBeam generated by the SPL 4MW, 2.2 GeV, proton Linac would be fired to the
same detector. Innovative ideas on higher and lower energy Beta Beams are also
described.Comment: To appear in the proceedings of 21st International Conference on
Neutrino Physics and Astrophysics (Neutrino 2004), Paris, France, 14-19 Jun
200