Solar neutrinos and neutrino physics

TL;DR

Solar neutrino research has been pivotal in advancing neutrino physics, confirming oscillation theories, measuring key parameters, and probing for new physics beyond the standard model through long-baseline, low-energy experiments.

Contribution

This paper reviews the development of neutrino propagation theory, experimental measurements of oscillation parameters, and the use of solar neutrinos to search for new physics beyond the standard model.

Findings

LMA MSW is the established solution to the solar neutrino problem.

Measured parameters include theta12 and Delta_m21^2; theta13 aligns with reactor data.

Solar neutrino studies set bounds on new physics such as sterile neutrinos and non-standard interactions.

Abstract

Solar neutrino studies triggered and largely motivated the major developments in neutrino physics in the last 50 years. Theory of neutrino propagation in different media with matter and fields has been elaborated. It includes oscillations in vacuum and matter, resonance flavor conversion and resonance oscillations, spin and spin-flavor precession, etc. LMA MSW has been established as the true solution of the solar neutrino problem. Parameters theta12 and Delta_m21^2 have been measured; theta13 extracted from the solar data is in agreement with results from reactor experiments. Solar neutrino studies provide a sensitive way to test theory of neutrino oscillations and conversion. Characterized by long baseline, huge fluxes and low energies they are a powerful set-up to search for new physics beyond the standard 3nu paradigm: new neutrino states, sterile neutrinos, non-standard neutrino interactions, effects of violation of fundamental symmetries, new dynamics of neutrino propagation, probes of space and time. These searches allow us to get stringent, and in some cases unique bounds on new physics. We summarize the results on physics of propagation, neutrino properties and physics beyond the standard model obtained from studies of solar neutrinos.