Limits on electron-neutrino oscillations from the GALLEX 51Cr source experiment

Abstract The recent result from the chromium source experiment carried out by the GALLEX collaboration implies interesting limits on the parameters Δm 2 and sin 2 2 θ describing neutrino oscillations. Values of Δm 2 > 0.17 eV 2 for maximal mixing and of sin 2 2 θ > 0.38 for Δm 2 > 1 eV 2 are ruled out at 90% C.L. This result improves by more than an order of magnitude previous limits on Δm 2 derived from electron-neutrino oscillation experiments at accelerators.