AAS 197, January 2001
Session 31. Solar System and The Sun
Oral, Monday, January 8, 2001, 1:30-3:00pm, Sunrise

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[31.07] Histogram Analysis of GALLEX, GNO and SAGE Neutrino Data: Further Evidence for Variability of the Solar Neutrino Flux

P.A. Sturrock (Stanford University), J.D. Scargle (NASA/Ames Research Center)

If the solar neutrino flux were constant, as is widely assumed, the histogram of flux measurements would be unimodal. On the other hand, sinusoidal or square-wave modulation may lead to a bimodal histogram. We here present evidence that the neutrino flux histogram is in fact bimodal. We analyze all available data from gallium experiments, coordinating results from the GALLEX and GNO experiments into one data set, and adopting results from the SAGE experiment as another data set. The two histograms, from the two data sets, are consistent in showing peaks in the range 45 - 75 SNU and 90 - 120 SNU, and a valley in between. By combining the data into one data set, we may form more detailed histograms; these strengthen the case that the flux is bimodal. A preliminary statistical analysis indicates that the bimodal character of the solar neutrino flux is highly significant. A bimodal flux distribution points towards variability, and variability points towards a nonzero neutrino magnetic moment.

We wish to acknowledge support (for PAS) by NASA grants NAS 8-37334 and NAGW-2265 and NSF grant ATM-9910215 and (for JDS) by the NASA Applied Information Systems Research Program.

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