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

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 $ν_μ$ charged-current interactions with an oscillatory dependence on $L_ν/E_ν$, where $L_ν$ is the neutrino propagation distance, and $E_ν$ is the neutrino energy. For contained-vertex atmospheric neutrino interactions, the $L_ν/E_ν$ resolution varies significantly from event to event. The precision of the oscillation measurement can be improved by incorporating information on $L_ν/E_ν$ resolution into the oscillation analysis. In the analysis presented here, a Bayesian technique is used to estimate the $L_ν/E_ν$ resolution of observed atmospheric neutrinos on an event-by-event basis. By separating the events into bins of $L_ν/E_ν$ resolution in the oscillation analysis, a significant improvement in oscillation sensitivity can be achieved.