Two experiments for the price of one? -- The role of the second oscillation maximum in long baseline neutrino experiments

TL;DR

This study assesses the importance of the second oscillation maximum in long baseline neutrino experiments, finding it marginal for most sensitivities except mass hierarchy, and highlights challenges in detecting non-standard interactions.

Contribution

The paper provides a quantitative analysis of the second oscillation maximum's role in neutrino experiments, including effects on standard and non-standard physics sensitivities.

Findings

Second maximum has limited impact on most sensitivities.

Detecting non-standard interactions is very challenging.

Mass hierarchy sensitivity benefits from the second maximum.

Abstract

We investigate the quantitative impact that data from the second oscillation maximum has on the performance of wide band beam neutrino oscillation experiments. We present results for the physics sensitivities to standard three flavor oscillation, as well as results for the sensitivity to non-standard interactions. The quantitative study is performed using an experimental setup similar to the Fermilab to DUSEL Long Baseline Neutrino Experiment (LBNE). We find that, with the single exception of sensitivity to the mass hierarchy, the second maximum plays only a marginal role due to the experimental difficulties to obtain a statistically significant and sufficiently background-free event sample at low energies. This conclusion is valid for both water Cherenkov and liquid argon detectors. Moreover, we confirm that non-standard neutrino interactions are very hard to distinguish experimentally from standard three-flavor effects and can lead to a considerable loss of sensitivity to \theta_{13}, the mass hierarchy and CP violation.