The probability distributions for random fluctuation of background counts are computed from Poisson statistics. Lastly, since the goal is to optimize on signal to noise rather than signal purity, the selection criteria used for this analysis may introduce different systematic errors than the atmospheric neutrino analysis. An energy estimator is a valuable tool to reject atmospheric neutrino background. However at this stage, the energy estimator is primarily used as a topological cut, as explained in section 3 . This analysis incorporates a selection criteria which significantly improves signal to noise for high energy neutrinos.
Further work is planned to develop a reliable energy estimator.