How Large Is the 7 Be Neutrino Flux from the Sun ?

On the basis of present solar neutrino observations and relaxing the constraints from solar models it is possible that most (or nearly all) of the flux of electron neutrinos detected comes from electron capture in Be. These solutions arise from neutrino oscillations in which νe − ντ mixing suppresses high energy νe and νe − νμ mixing suppresses low energy νe as qualitatively suggested from some SO(10) grand unified models. The importance of future observations is emphasized.