Abstract: (arXiv)
The 8^8B solar neutrino flux as measured by Super-Kamiokande is consistent with the 37^{37}Ar production rate in 37^{37}Cl at Homestake. GALLEX and SAGE, continue to observe 71^{71}Ge production rates in 71^{71}Ga that are consistent with the minimal signal expected from the solar luminosity. The observed 8^8B solar neutrino flux is in good agreement with that predicted by the standard solar model of Dar and Shaviv with nuclear reaction rates that are supported by recent measurements of nuclear fusion cross sections at low energies. The measurements of Super-Kamiokande, SAGE and GALLEX suggest that the expected the pep, 7^7Be and NO solar neutrino fluxes are strongly suppressed. This can be explained by neutrino oscillations and the Mikheyev-Smirnov-Wolfenstein effect. Since neither a flavor change, nor a terrestrial variation, nor a spectral distortion of the 8^8B solar neutrino flux has been observed yet, the solar neutrino problem does not provide conclusive evidence for neutrino properties beyond the standard electroweak model. The deviations of the experimental results from those predicted by the standard solar models may reflect the approximate nature of of solar models and of our knowledge of nuclear reaction rates, radiation transport and particle diffusion in dense stellar plasmas. Only future observations of spectral distortions, or terrestrial modulation or flavor change of solar neutrinos in solar neutrino experiments, such as Super-Kamiokande, SNO, Borexino and HELLAZ will be able to establish that neutrino properties beyond the minimal standard electroweak model are responsible for the solar neutrino problem.
Note:
  • To be published in Physics Reports, Proceedings of ``From Atomic Nuclei to Stars and Galaxies'' Haifa, January 12-16, 1998. No enclosed figures
  • talk: Haifa 1998/01/12
  • neutrino: solar
  • neutrino: flux
  • boron
  • luminosity: sum rule
  • beryllium
  • model: solar
  • neutrino: oscillation
  • electroweak interaction
  • nucleus nucleus: nuclear reaction