Neutrino electromagnetic properties

TL;DR

This paper reviews the electromagnetic properties of neutrinos, including theoretical form factors, experimental constraints, and related processes, providing a comprehensive overview of current knowledge and research directions.

Contribution

It offers a detailed derivation of neutrino electromagnetic vertex functions and discusses experimental limits, highlighting recent advances and remaining challenges in understanding neutrino electromagnetic interactions.

Findings

Derivation of neutrino electromagnetic vertex functions for Dirac and Majorana neutrinos

Summary of experimental constraints on neutrino magnetic moments

Discussion of neutrino electromagnetic processes like radiative decay and spin-flavor precession

Abstract

The main goal of the paper is to give a short review on neutrino electromagnetic properties. In the introductory part of the paper a summary on what we really know about neutrinos is given: we discuss the basics of neutrino mass and mixing as well as the phenomenology of neutrino oscillations. This is important for the following discussion on neutrino electromagnetic properties that starts with a derivation of the neutrino electromagnetic vertex function in the most general form, that follows from the requirement of Lorentz invariance, for both the Dirac and Majorana cases. Then, the problem of the neutrino form factors definition and calculation within gauge models is considered. In particular, we discuss the neutrino electric charge form factor and charge radius, dipole magnetic and electric and anapole form factors. Available experimental constraints on neutrino electromagnetic properties are also discussed, and the recently obtained experimental limits on neutrino magnetic moments are reviewed. The most important neutrino electromagnetic processes involving a direct neutrino coupling with photons (such as neutrino radiative decay, neutrino Cherenkov radiation, spin light of neutrino and plasmon decay into neutrino-antineutrino pair in media) and neutrino resonant spin-flavor precession in a magnetic field are discussed at the end of the paper.