Detecting the Upturn of the Solar $^8$B Neutrino Spectrum with LENA

TL;DR

The paper demonstrates that the LENA detector can precisely measure the solar $^8$B neutrino spectrum and detect its predicted upturn with high statistical significance within five years.

Contribution

It introduces the potential of the LENA detector to observe the spectral upturn of solar $^8$B neutrinos, testing neutrino oscillation models in the transition region.

Findings

Detection of the spectral upturn with 5 sigma significance after 5 years.

High-precision measurement enabled by the large target mass and low energy threshold.

Monte Carlo simulations support the feasibility of the measurement.

Abstract

LENA (Low Energy Neutrino Astronomy) has been proposed as a next generation 50 kt liquid scintillator detector. The large target mass allows a high precision measurement of the solar $^8$B neutrino spectrum, with an unprecedented energy threshold of 2 MeV. Hence, it can probe the MSW-LMA prediction for the electron neutrino survival probability in the transition region between vacuum and matter-dominated neutrino oscillations. Based on Monte Carlo simulations of the solar neutrino and the corresponding background spectra, it was found that the predicted upturn of the solar $^8$B neutrino spectrum can be detected with 5 sigma significance after 5 y.