450 research outputs found
What will the first year of SNO show?
The ratio of the measured to the predicted standard model CC event rates in
SNO will be 0.47 if no oscillations occur. The best-fit active oscillation
predictions for the CC ratio are: 0.35-39 (MSW) and 0.38-42 (vacuum) (all for a
5 MeV energy threshold), typically about 20% less than the no-oscillation
expectation. We calculate the predicted ratios for six active and sterile
neutrino oscillation solutions allowed at 99% CL and determine the dependence
of the ratios on energy threshold. If the high-energy anomaly observed by
SuperKamiokande is due to an enhanced hep flux, MSW active solutions predict
that out of a total of 5000 CC events above 5 MeV in SNO between 49 and 54
events will be observed above 13 MeV whereas only 19 events are expected for
no-oscillations and a nominal standard hep flux.Comment: Phys Lett accepted. Editorial corrections. Related material and
viewgraphs at http://www.sns.ias.edu/~jn
Recent Work on Standard Solar Models
Recent results on standard solar models are reviewed. I shall summarize
briefly three of the themes that I stressed at the Neutrino '92 Conference: 1)
Different solar model codes give the same answers when the same input data are
used; 2) Improved calculations of standard solar models include helium
diffusion, the Livermore radiative opacity, the meteoritic iron abundance, and
a variety of other corrections; and 3) There are a few basic rules that should
be followed in using standard solar models. At the Neutrino '92 Conference, I
reviewed in more detail the recent work on standard solar models by Marc
Pinsonneault and myself. This work has by now appeared in print (Rev. Mod.
Phys. 64, 885, 1992, hereafter Paper I, and ApJ Letters, 69, 717, 1992, Paper
II). Therefore, there is no need for me to repeat the details here.Comment: 4 pages, Institute for Advanced Study number AST 92/5
What Do Solar Models Tell Us About Solar Neutrino Experiments?
If the published event rates of the chlorine and Kamiokande solar neutrino
experiments are correct, then the energy spectrum of neutrinos produced by the
decay of B in the sun must be different from the energy spectrum determined
from laboratory nuclear physics measurements. This change in the energy
spectrum requires physics beyond the standard electroweak model. In addition,
the GALLEX and SAGE experiments, which currently have large statistical
uncertainties, differ from the predictions of the standard solar model by and , respectively.Comment: 4 pages (LaTeX file, figures not included
Solar Neutrinos: Where We Are, Where We Are Going
This talk answers a series of questions. Why study solar neutrinos? What does
the combined standard model (solar plus electroweak) predict for solar
neutrinos? Why are the calculations of neutrino fluxes robust? What are the
three solar neutrino problems? What have we learned in the first thirty years
of solar neutrino research? For the next decade, what are the most important
solvable problems in the physics of solar neutrinos? What are the most
important problems in the astrophysics of solar neutrinos?Comment: uuencoded Z-compressed postscript file; 36 pages with figures. To be
published in the Astrophysical Journa
Solar Neutrinos: What Next?
I summarize the current state of solar neutrino research and then give my
answer to the question: What should we do next?Comment: NNN99 Workshop, viewgraphs and related information at
http://www.sns.ias.edu/~jn
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