What can four solar neutrino experiments tell us about the magnetic moment solution to the solar neutrino problem?

Abstract

The results reported by the four solar neutrino experiments (Homestake, Kamiokande, SAGE, Gallex) are analyzed from the point of view of the magnetic moment solution to the solar neutrino problem. The neutrino deficit reported by the gallium experiments (SAGE, Gallex) is apparently not as large as the one reported by Homestake and Kamiokande, a phenomenon suggesting a greater suppression in the large energy solar neutrino sector but also consistent with a uniform suppression for all neutrinos. Both uniform and nonuniform suppressions are examined for three different variants of the solar magnetic field and the possible parameter ranges for $\ensuremath{\Delta}^{2}m_{21}$ and ${\ensuremath{\mu}}_{\ensuremath{\nu}}$ are investigated. Massless neutrinos are not excluded and in all cases $\ensuremath{\Delta}^{2}m_{21}<{10}^{\ensuremath{-}5}$ e${\mathrm{V}}^{2}$. The anticorrelation of the neutrino flux with sunspot activity is possible in any of the experiments but is in no way implied by a sizable magnetic moment and magnetic field.