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Old May 8th 05, 01:53 PM
Jonathan Thornburg -- remove -animal to reply
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In sci.astro.research Ray Tomes wrote:
The solar neutrino problem is discussed in the Physics FAQ at:
http://math.ucr.edu/home/baez/physic..._neutrino.html
In essence, the detected number of neutrinos is consistently smaller
than the expected number based on the known nuclear reaction energy that
is released.


At the top of that web page we find the words
| Updated 1998 by John Bahcall.
| Updated 1994 by SIC.

In other words, that web page is 7 years old. We've learned a *lot*
about the solar neutrino problem in the last 7 years.

For a nice non-technical overview of what we now know, see Bahcall's
article
http://nobelprize.org/physics/articles/bahcall/
(= physics/0406040)
# The three years 2001 to 2003 were the golden years of solar neutrino
# research. In this period, scientists solved a mystery with which they
# had been struggling for four decades. The solution turned out to be
# important for both physics and for astronomy. In this article, I tell
# the story of those fabulous three years.

For a more technical account, see McDonald's review article
astro-ph/0406253:

Title: Solar Neutrino Measurements
Authors: A.B. McDonald
Comments: Review Article on Solar neutrino experiments, 18 pages, 4 figures,
submitted to Focus Issue on Neutrino Physics, to be published in
New Journal of Physics (www.njp.org)
Journal-ref: New J.Phys. 6 (2004) 121
Abstract:
A review of solar neutrino experiments is provided, including experimental
measurements to date and proposed future measurements. Experiments
to date have provided a clear determination that solar neutrinos are
undergoing flavor transformation and that the dominant mechanism for this
transformation is oscillation. The mixing parameters are well defined and
limits are placed on sub-dominant modes. The measurements also provide
strong confirmation of solar model calculations. New experiments under
development will study neutrino oscillation parameters and sub-dominant
modes with greater precision and will investigate solar fluxes further,
concentrating primarily on the low energy pp, $^7$Be, pep and CNO
reactions.

Any new theory of the solar neutrino problems needs to confront --
in a *detailed* *quantitative* manner -- the extensive data described
in these papers (as well as much other data, notably the high-precision
helioseismological measurements of sound speed at various depths within
the sun).

ciao,

--
-- "Jonathan Thornburg (remove -animal to reply)"
Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut),
Golm, Germany, "Old Europe" http://www.aei.mpg.de/~jthorn/home.html
"Washing one's hands of the conflict between the powerful and the
powerless means to side with the powerful, not to be neutral."
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