Standard Physics Solution To The Solar Neutrino Problem?

Abstract

The $^8$B solar neutrino flux predicted by the standard solar model (SSM) is consistent within the theoretical and experimental uncertainties with that observed at Kamiokande. The Gallium and Chlorine solar neutrino experiments, however, seem to imply that the $^7$Be solar neutrino flux is strongly suppressed compared with that predicted by the SSM. If the $^7$Be solar neutrino flux is suppressed, still it can be due to astrophysical effects not included in the simplistic SSM. Such effects include short term fluctuations or periodic variation of the temperature in the solar core, rotational mixing of $^3$He in the solar core, and dense plasma effects which may strongly enhance p-capture by $^7$Be relative to e-capture. The new generation of solar observations which already look non stop deep into the sun, like Superkamiokande through neutrinos, and SOHO and GONG through acoustic waves, may point at the correct solution. Only Superkamiokande and/or future solar neutrino experiments, such as SNO, BOREXINO and HELLAZ, will be able to find out whether the solar neutrino problem is caused by neutrino properties beyond the minimal standard electroweak model or whether it is just a problem of the too simplistic standard solar model.

Invited talk presented at ``Neutrino 1996'', Helsinki, Finland, June 12-17, 1996, Zuos Summer School On Physics With Neutrinos, Zuos, Switzerland, August 4-10, 1996, and ``New Worlds In Astroparticle Physics'', Faro, Portugal, September 8-10, 1996