Neutrino propagation in media: Flavor-, helicity-, and pair correlations

TL;DR

This paper derives detailed equations for neutrino behavior in media, including flavor, helicity, and pair correlations, highlighting new corrections and electromagnetic effects in anisotropic environments.

Contribution

It provides a refined derivation of neutrino equations of motion in anisotropic media, including a correction for Majorana neutrinos and a new mean-field Hamiltonian for electromagnetic interactions.

Findings

Confirmed previous results on neutrino correlations with a minor correction for Majorana neutrinos.

Derived a new mean-field Hamiltonian for neutrino electromagnetic interactions.

Discussed the phenomenology of pair correlations versus helicity correlations.

Abstract

Neutrinos propagating in media (matter and electromagnetic fields) undergo flavor and helicity oscillations, where helicity transitions are instigated both by electromagnetic fields and matter currents. In addition, it has been shown that correlations between neutrinos and antineutrinos of opposite momentum can build up in anisotropic media. We re-derive the neutrino equations of motion in the mean-field approximation for homogeneous yet anisotropic media, confirming previous results except for a small correction in the Majorana case. Furthermore, we derive the mean-field Hamiltonian induced by neutrino electromagnetic interactions. We also provide a phenomenological discussion of pair correlations in comparison with helicity correlations.