Neutrino Energy Spectra

The Shape of the 8B Energy Spectrum is Independent of Solar Conditions

Super-Kamiokande and SNO will both measure the shape of the solar neutrino energy spectrum that reaches the earth. This spectrum is independent of conditions in the solar interior to an accuracy of 1 part in 100,000. The principal effects of the solar environment are the motions of the ions, which lead to Doppler shifts of the neutrinos, and the gravitational redshift caused by the solar mass. The gravitational redshift is small, but is the dominant solar influence on the shape of the energy spectrum. The probability, P(E), of a solar neutrino having an energy, E, is reflected by the gravitational redshift, (1 + ), where is the gravitational potential. The correction term in the brackets is due to the Doppler motions of the 8B ions. The derivation of these results is given in the paper whose reference appears in the viewgraph.

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Standard Solar Neutrino Energy Spectrum. The energy Spectrum of neutrinos from the pp chain of interactions in the Sun, as predicted by the standard solar model.

The energy Spectrum of neutrinos from the pp chain of interactions in the Sun, as predicted by the standard solar model. Neutrino fluxes from continuum sources (such as pp and 8B) are given in the units of counts per cm2 per second. The pp chain is responsible for more than 98% of the energy generation in the standard solar model. Neutrino produced in the carbon-nitrogen-oxygen CNO chain are not important energetically and are difficult to detect experimentally. The arrows at the top of the figure indicate the energy thresholds for the ongoing neutrino experiments.

From the paper ``Solar Neutrinos: Where We Are, Where We Are Going,'' ApJ 467, 475 (1996), hep-ph/9512285, updated using the data given in astro-ph/9805135.

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The postscript files will print out correctly (landscape mode) for use as viewgraphs. However, they will look rotated by 90 degrees if viewed with ghostview. If you want to use this postscript file to reproduce in a paper, you will need to use a program that will rotate the figure by 90 degrees with TeX commands (top of the file put \input psfig and wherever you want the figure put \psfig{, width=6in,angle=-90}).

The best-estimate (standard) 8B neutrino spectrum , together with the spectra ± allowed by the maximum (± 3) theoretical and experimental uncertainties.

This viewgraph is Figure 5 from the paper ``Standard Neutrino Spectrum from 8B Decay'' by John Bahcall, Eligio Lisi, D. E. Alburger, L. De Braeckeleer, S. J. Freedman, and J. Napolitano. Phys. Rev. C 54, 411 (1996), nucl-th/9601044.

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