Solar neutrinos: Theory versus observation

Abstract

The current state of the solar neutrino problem is described. The predictions of solar models (standard and nonstandard) are reviewed. The neutrino absorption cross sections for all detectors of current interest are reviewed with special emphasis on the uncertainties that exist in the calculations for each target. A long-term program for neutrino spectroscopy of the solar interior is outlined. It is shown, in addition, that stellar collapses can be detected within the galaxy by the proposed solar neutrino detectors.

Solar interior structure and luminosity variations

“…A brief summary of the present state of the problem is given by Bahcall (1979), where further references may be found. In order to construct a solar model with a low neutrino luminosity and Z = 0.02 it is evidently necessary to deviate from the so-called standard theory, which many stellar astrophysicists seem reluctant to do It is obvious, of course, that when one considers this possibility, one must be acutely aware of the observational implications, and in particular one must seek ways of testing any hypothesis.…”

The3He(?,?)7Be reaction and the solar neutrino problem

“…This detection method is sensitive primarily to the high energy neutrinos from the decay SB~SBe+e++v [2][3][4][5][6][7], where SB is produced in the p-p chain [8,9]. The 37C1 neutrino detector is primarily sensitive to the high energy neutrinos from the 8B decay [1][2][3][4][5][6][7] ( Fig. The indicated branching ratios [-5] are very sensitive to the solar temperature and require a detailed solar model.…”

“…The 37C1 neutrino detector is primarily sensitive to the high energy neutrinos from the 8B decay [1][2][3][4][5][6][7] ( Fig. The rate predicted by the standard solar model first experienced [2][3][4][5][6][7] a decrease reaching a value as low as 4.7 +_I.6SNU and more recently an increase to the value of 7.3_+1.5"* SNU, mainly due to the use of improved versions of stellar opacities and to a reevaluation of nuclear and astrophysical parameters. The observations yield [1], as an average of the runs from 1970 to 1979, a rate in Solar Neutrino Units* of 2.2_+0.4 SNU.…”

The Advanced Solar Observatory

“…The cause of this modulation of the solar activity level is unknown. (7) The recognition, as a result of observations of hard x rays, gamma rays, and energetic neutrons, that the energy released during the impulsive phase of a flare is initially largely, or entirely, contained in nonthermal particles accelerated during magnetic-reconnection processes in the coronal 14 (8) The discovery that the ejection of large clouds of gas called coronal mass transients can accompany some 15 The profound impact of these and other discoveries on our appreciation of the complexity and diversity of solar phenomena has led to the maturing of solar physics as a scientific discipline. This new maturity has allowed solar physicists to formulate a much more precise theoretical and observational strategy for their discipline.…”