A Bayesian technique for improving the sensitivity of the atmospheric neutrino L/E analysis

Abstract

This paper outlines a method for improving the precision of atmospheric neutrino oscillation measurements. One experimental signature for these oscillations is an observed deficit in the rate of $\hat{I}{½}_{\hat{I}}¼$ charged-current interactions with an oscillatory dependence on $L_{\hat{I}}½/E_{\hat{I}}½$, where $L_{\hat{I}}½$ is the neutrino propagation distance, and $E_{\hat{I}}½$ is the neutrino energy. For contained-vertex atmospheric neutrino interactions, the $L_{\hat{I}}½/E_{\hat{I}}½$ resolution varies significantly from event to event. The precision of the oscillation measurement can be improved by incorporating information on $L_{\hat{I}}½/E_{\hat{I}}½$ resolution into the oscillation analysis. In the analysis presented here, a Bayesian technique is used to estimate the $L_{\hat{I}}½/E_{\hat{I}}½$ resolution of observed atmospheric neutrinos on an event-by-event basis. By separating the events into bins of $L_{\hat{I}}½/E_{\hat{I}}½$ resolution in the oscillation analysis, a significant improvement in oscillation sensitivity can be achieved.

12 pages, 7 figures, submitted to Nucl. Instrum. Methods A, accompanies arXiv:1208.2915 [hep-ex]