Possible evidence for neutrino oscillations in the Brookhaven solar-neutrino experiment

Pomeranchuk has suggested that one might directly observe neutrino oscillations in a solar-neutrino experiment if the oscillation wavelength were comparable to the annual earth-sun-distance variation from perihelion to aphelion, $\Delta r=5\mathrm{}\times {10}^6$km. We find that data from the Brookhaven solar-neutrino experiment can be interpreted to marginally favor the neutrino-oscillation hypothesis at the 2-standard-deviation level. If the effect is not a statistical fluctuation, the estimated value for $\Delta m^2=m_{{\nu }_1}^{}{}_{}{}^2-m_{{\nu }_2}^{}{}_{}{}^2\sim 4\times {10}^{-10\mathrm{}}$ e${\mathrm{V}}^2$ is such that terrestrial tests would seem to be unfeasible.