The solar neutrino discrepancy

Since many years the observational upper limit to the argon production in the Brookhaven solar neutrino observatory of Davis is almost by an order of magnitude below theoretical estimates based on standard physical and astrophysical assumptions. Many new mechanisms have been proposed to account for this discrepancy. It is thus possible to suppose that the coupling of the neutrinos to the gravitational field is so strong that the solar neutrinos arrive gravitationally red-shifted at the Earth, and are unable to produce argon in the threshold reaction on chlorine. In order to be able to attribute the discrepancy to gravitation, it is necessary first to show in an experiment with a terrestrial neutrino source that the rate of argon production in a chlorine target confirms the predictions based on the current theory of weak interactions. (orig.)