Non-Standard Models, Solar Neutrinos, and Large \theta_{13}

TL;DR

This paper investigates non-standard neutrino models and the impact of a large 3 angle on solar neutrino data, finding current data insufficient to distinguish between models due to uncertainties.

Contribution

It evaluates non-standard neutrino interaction models and solar density modifications, assessing their fit to solar neutrino data in light of recent 3 measurements.

Findings

Some non-standard models fit data better but lack statistical significance.

Large 3 reduces the distinction between models.

Solar density profile changes do not produce flatter survival probabilities.

Abstract

Solar neutrino experiments have yet to see directly the transition region between matter-enhanced and vacuum oscillations. The transition region is particularly sensitive to models of non-standard neutrino interactions and propagation. We examine several such non-standard models, which predict a lower-energy transition region and a flatter survival probability for the ^{8}B solar neutrinos than the standard large-mixing angle (LMA) model. We find that while some of the non-standard models provide a better fit to the solar neutrino data set, the large measured value of \theta_{13} and the size of the experimental uncertainties lead to a low statistical significance for these fits. We have also examined whether simple changes to the solar density profile can lead to a flatter ^{8}B survival probability than the LMA prediction, but find that this is not the case for reasonable changes. We conclude that the data in this critical region is still too poor to determine whether any of these models, or LMA, is the best description of the data.