The most important nuclear physics experiment to perform in
connection with solar neutrino research is an accurate remeasurement
of the proton capture rate on 7Be. The flux of the higher
energy neutrinos (from 8B beta-decay) that is measured in
the Kamiokande, Super-Kamiokande, and SNO solar neutrino experiments
is proportional to the low energy value for the proton capture cross
section. According to the combined standard model (standard solar
model and standard electroweak theory), the rate measured in the
chlorine solar neutrino experiment is also proportional to this cross
section. The rate at which 8B is produced in the sun is so
slow that the value of the proton capture cross section on 7Be
that is assumed in the solar model calculations has no perceptible
effect on the solar models. This is the reason for the linear
dependence of the 8B neutrino flux on the 8B production
cross section. If you want to cite a reference for this viewgraph,
(in order to help support your proposal or for whatever reason), see
pg. 482 of ``Solar Neutrinos: Where We Are, Where We Are
Going,'' ApJ 467, 475 (1996), hep-ph/9512285.
Color Viewgraph
Black and White Viewgraph
The flux of 7Be solar neutrinos is relatively accurately
determined by standard solar models, but-if one assumes nothing
happens to solar neutrinos after they are created-the7Be
neutrinos appear to be almost entirely absent in the gallium and
chlorine solar neutrino experiments. This is one of the most severe
aspects of the ``solar neutrino problem.'' This viewgraph shows that
the flux of 7Be solar neutrinos is independent of the rate
at which 8B neutrinos are produced by the relatively less
certain cross section for proton capture on 7Be. The
reason is that the proton capture, which gives rise to 8B
neutrinos, is very much slower than the electron capture that gives
rise to 7Be neutrinos. The argument that supports this
viewgraph is given in detail in the text following and preceding
equation (6) of ApJ 467, 475 (1996).
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