Probing non-standard neutrino-electron interactions with solar and reactor neutrinos

TL;DR

This paper investigates how non-standard neutrino-electron interactions, which are predicted by many neutrino mass models, affect solar neutrino behavior and detection, providing constraints comparable to existing bounds.

Contribution

It analyzes the impact of non-universal flavor-conserving neutrino-electron interactions on solar neutrino phenomenology, including propagation and detection effects.

Findings

Limits on non-standard interactions are comparable to existing constraints.

Non-standard interactions modify MSW neutrino propagation.

Detection cross sections are affected by these interactions.

Abstract

Most neutrino mass extensions of the standard electroweak model entail non-standard interactions which, in the low energy limit, can be parametrized in term of effective four-fermion operators $\nu_\alpha \nu_\beta \bar f f $. Typically of sub-weak strength, $\epsilon_{\alpha \beta} G_F$, these are characterized by dimensionless coupling parameters, $\epsilon_{\alpha \beta}$, which may be relatively sizeable in a wide class of schemes. Here we focus on non-universal (NU) flavor conserving couplings ($\alpha = \beta$) with electrons ($f = e$) and analyse their impact on the phenomenology of solar neutrinos. We consistently take into account their effect both at the level of propagation where they modify the standard MSW behavior, and at the level of detection, where they affect the cross section of neutrino elastic scattering on electrons. We find limits which are comparable to other existing model-independent constraints.