Atmospheric Neutrino Unblinding Proposal
AMANDA-II 2000-2006

John Kelley, UW-Madison, May 2008



Analysis Methodology

Data Selection


Systematic Errors





1. Overview

We present an unblinding proposal for an analysis of the AMANDA-II atmospheric neutrino data from the years 2000 to 2006. This sample of over 6000 well-reconstructed, high-energy upgoing neutrino events presents the opportunity to test various hypotheses of physics beyond the Standard Model from 100 GeV to 10 TeV. In the absence of any such effects, we can use the same techniques to measure the atmospheric neutrino flux parameters as compared to published predictions.


Signatures of new physics are visible as distortions in the zenith angle / energy spectrum. To that end, we perform a likelihood analysis on the reconstructed zenith angle / Nch (number of channels hit) distribution to quantify the probability that the data are consistent with various hypotheses. Such an analysis is statistically very powerful; at the same time, we must be conscious of systematic errors that can change not on the normalization but the shape of these distributions, such as optical module (OM) sensitivity. We have performed a quantitative survey of such errors and have integrated the uncertainties into the analysis procedure.


We also present details of the data selection, which is an extension of the 2000-2004 sample used in the Zeuthen 5-year point source search. Various issues of purity and possible background contamination are discussed.


Finally, we present our sensitivity to both new physics parameters or, in the absence of new physics, sensitivity to the normalization and slope deviation from standard predictions for the neutrino flux. The latter "forward folding" approach allows us to define an allowed range of energy spectra for the atmospheric neutrino flux.