Power-spectrum analysis of Super-Kamiokande solar neutrino data, taking into account asymmetry in the error estimates

Abstract

The purpose of this article is to carry out a power-spectrum analysis (based on likelihood methods) of the Super-Kamiokande 5-day dataset that takes account of the asymmetry in the error estimates. Whereas the likelihood analysis involves a linear optimization procedure for symmetrical error estimates, it involves a nonlinear optimization procedure for asymmetrical error estimates. We find that for most frequencies there is little difference between the power spectra derived from analyses of symmetrized error estimates and from asymmetrical error estimates. However, this proves not to be the case for the principal peak in the power spectra, which is found at 9.43 yr-1. A likelihood analysis which allows for a "floating offset" and takes account of the start time and end time of each bin and of the flux estimate and the symmetrized error estimate leads to a power of 11.24 for this peak. A Monte Carlo analysis shows that there is a chance of only 1% of finding a peak this big or bigger in the frequency band 1 - 36 yr-1 (the widest band that avoids artificial peaks). On the other hand, an analysis that takes account of the error asymmetry leads to a peak with power 13.24 at that frequency. A Monte Carlo analysis shows that there is a chance of only 0.1% of finding a peak this big or bigger in that frequency band 1 - 36 yr-1. From this perspective, power spectrum analysis that takes account of asymmetry of the error estimates gives evidence for variability that is significant at the 99.9% level. We comment briefly on an apparent discrepancy between power spectrum analyses of the Super-Kamiokande and SNO solar neutrino experiments.

arXiv comment13 pages, 2 tables, 6 figures

References in corpus (12)

• Solar 8B and hep Neutrino Measurements from 1258 Days of Super-Kamiokande Data
• Determination of Solar Neutrino Oscillation Parameters using 1496 Days of Super-Kamiokande-I Data
• Complete results for five years of GNO solar neutrino observations
• A Search for Periodicities in the ${}^8$B Solar Neutrino Flux Measured by the Sudbury Neutrino Observatory
• A search for periodic modulations of the solar neutrino flux in Super-Kamiokande-I
• Rotational Signature and Possible R-Mode Signature in the GALLEX Solar Neutrino Data
• Power-Spectrum Analyses of Super-Kamiokande Solar Neutrino Data: Variability and its Implications for Solar Physics and Neutrino Physics
• Analysis of Super-Kamiokande 5-day Measurements of the Solar Neutrino Flux
• Time-Series Analysis of Super-Kamiokande Measurements of the Solar Neutrino Flux
• Evidence for Solar Neutrino Flux Variability and its Implications
• Review of Methods of Power-Spectrum Analysis as Applied to Super-Kamiokande Solar Neutrino Data
• A Search for Periodicity in the Super-Kamiokande Solar Neutrino Flux Data

Cited by in corpus (12)

• Neutrino Oscillations as a Probe of Light Scalar Dark Matter
• Indications of r-mode Oscillations in SOHO/MDI Solar Radius Measurements
• A search for evidence of solar rotation in Super-Kamiokande solar neutrino dataset
• Further Evidence Suggestive of a Solar Influence on Nuclear Decay Rates
• Solar neutrino variability and its implications for solar physics and neutrino physics
• Evidence for R-Mode Oscillations in Super-Kamiokande Solar Neutrino Data
• Numerical Simulations of Torsional Alfvén Waves in Axisymmetric Solar Magnetic Flux Tubes
• Astrophysics in 2006
• Anomalies in Radioactive Decay Rates: A Bibliography of Measurements and Theory
• Comparative Analysis of Super-Kamiokande and SNO Solar-Neutrino Data and the Photospheric Magnetic Field
• Generalized Lomb-Scargle analysis of ${}^{36}\mathrm{Cl}$ decay rate measurements at PTB and BNL
• Neutrino-Flux Variability, Nuclear-Decay Variability, and Their Apparent Relationship