Neutrino-electron scattering and the choice between different Mikheyev-Smirnov-Wolfenstein solutions of the solar neutrino problem

We consider the scattering of solar neutrinos by electrons as a means for distinguishing between different MSW solutions of the solar neutrino problem. In terms of the ratio R between the observed cross section and that for pure electron-type neutrinos, we find some correlation between the value of R and each solution. A value of R ≤ 1/3 implies that the adiabatic solution is correct, while values between 1/3 and 3/5 are consistent with the large-angle solution. A value close to 1/2 is also consistent with the nonadiabatic solution, and a value less than ((1/6--1) / 7) implies oscillations into sterile neutrinos