"The 7Be(p,gamma)8B Reaction and the Solar Neutrino Problem"

Carl A. Gagliardi

Cyclotron Institute
Texas A&M University

Abstract

Various solar neutrino and neutrino oscillation experiments, especially Super-Kamiokande, have found strong evidence for the existence of neutrino oscillations in recent years. These oscillations provide simultaneous evidence that neutrinos both have mass and mix. Now efforts are focusing on determinations of the detailed properties of neutrinos from solar and terrestrial neutrino experiments. Most (or all) of the neutrinos detected by the majority of solar neutrino experiments originate from the beta decay of 8B, which is produced in the sun via the 7Be(p,gamma)8B proton capture reaction. The rate of this reaction at solar energies (E_cm ~ 20 keV) is the most uncertain input to solar model calculations of the neutrino production rates. Several groups are investigating this reaction, using both direct and indirect techniques, in order to reduce the uncertainty in the 8B production rate. I'll describe the various methods and their current status, with a particular emphasis on the "asymptotic normalization" technique that we have developed at Texas A&M to determine astrophysical reaction rates from measurements of proton-transfer reactions.