Seasonal Variations of the 7Be Solar Neutrino Flux

TL;DR

This paper explores how seasonal variations in 7Be solar neutrino flux measurements can independently determine neutrino properties and detect vacuum oscillations, providing a background-independent approach with potential for conclusive results after three years of data.

Contribution

It introduces a method to use seasonal variation data from Borexino and KamLAND to measure neutrino flux and oscillations independently of solar models and backgrounds.

Findings

Vacuum neutrino oscillations can be confirmed or excluded after three years.

Seasonal variation measurements can determine neutrino oscillation parameters.

Method is robust against background uncertainties.

Abstract

Measuring the 7Be solar neutrino flux is crucial towards solving the solar neutrino puzzle. The Borexino experiment, and possibly the KamLAND experiment, will be capable of studying the 7Be neutrinos in the near future. We discuss (1) how the seasonal variation of the Borexino and KamLAND data can be used to measure the 7Be solar neutrino flux in a background independent way and (2) how anomalous seasonal variations might be used to discover vacuum neutrino oscillations, independent of the solar model and the measurement of the background. In particular, we find that, after three years of Borexino or KamLAND running, vacuum neutrino oscillations can be either established or excluded for almost all values of (sin^2 2 theta, Delta m^2) preferred by the Homestake, GALLEX, SAGE, and Super-Kamiokande data. We also discuss how well seasonal variations of the data can be used to measure (sin^2 2 theta, Delta m^2) in the case of vacuum oscillations.