Solar Neutrino Cross Sections and Nuclear Beta Decay

Abstract

The neutrino-producing reactions that are believed to occur in the interior of the sun are reviewed and the predicted neutrino fluxes from these reactions are presented. The relevant absorption cross sections for neutrino-induced transitions from the ground state of ${\mathrm{Cl}}^{37}$ to various states in ${\mathrm{Ar}}^{37}$ are then calculated. The nuclear model adopted in these calculations is also used to predict the decay rates and branching ratios for a number of nuclei with $1{d_{\frac{3}{2}}}^n$ configurations; comparisons with experiment are made wherever possible and additional tests are suggested. A method for extracting Gamow-Teller matrix elements from mixed transitions between members of the same isotopic multiplet is then illustrated. The theory of bound-state neutrino capture is also outlined and applied to the proposed solar neutrino experiment. In an Appendix, some neutrino cross sections that are useful in interpreting the reactor experiment of Davis are presented.