Short-baseline Neutrino Oscillation Waves in Ultra-large Liquid Scintillator Detectors

TL;DR

This paper explores the potential of upcoming large liquid scintillator neutrino detectors, like LENA and NOvA, to detect short-baseline neutrino oscillations using decay-at-rest sources, providing new avenues for confirming or refuting existing anomalies.

Contribution

It demonstrates how large liquid scintillator detectors can be used with decay-at-rest sources to observe short-baseline neutrino oscillations, offering unprecedented sensitivity and verification capabilities.

Findings

LENA can test LSND and MiniBooNE signals at > 5 sigma.

LENA and NOvA have complementary sensitivities to reactor anomalies.

Detectors can observe oscillation waves over their length, enabling direct verification.

Abstract

Powerful new multi-kiloton liquid scintillator neutrino detectors, including NOvA and LENA, will come on-line within the next decade. When these are coupled with a modest-power decay-at-rest (DAR) neutrino source at short-baseline, these detectors can decisively address the recent ambiguous signals for neutrino oscillations at high Delta m^2. These detectors are > 50 m long, and so with a DAR beam, the characteristic oscillation wave will be apparent over the length of the detector, providing a powerful verification of the oscillation phenomena. LENA can simultaneously perform numubar to nuebar appearance and nue to nue disappearance searches with unprecedented sensitivity. NOvA is likely limited to nue disappearance given its present design, but also has excellent sensitivity in the high Delta m^2 region. For the appearance channel, LENA could provide a stringent test of the LSND and MiniBooNE signal regions at > 5 sigma with a reduced fiducial volume of 5 kt and a 10 kW neutrino source. In addition, the LENA and NOvA disappearance sensitivities in nue mode are complementary to the recent reactor anomaly indicating possible nuebar disappearance and would cover this possible oscillation signal at the 3 sigma level.