Neutrino propagation in matter with general interactions

TL;DR

This paper analyzes how various Lorentz-invariant interactions, including tensor interactions, affect neutrino propagation in matter, revealing new effects like spin-flip phenomena induced by tensor potentials.

Contribution

It introduces a comprehensive framework for neutrino effective potentials considering general interactions, highlighting the role of tensor interactions in polarized media.

Findings

Tensor interactions can induce neutrino spin-flip.

Transverse tensor potentials affect neutrino propagation.

Tensor interactions are significant alongside vector and axial vector terms.

Abstract

We present a general analysis of the effective potential for neutrino propagation in matter, assuming a generic set of Lorentz invariant non-derivative interactions. We find that in addition to the known vector and axial vector terms, in a polarized medium also tensor interactions can play an important role. We compute the effective potential arising from a tensor interaction. We show that the components of the tensor potential transverse to the direction of the neutrino propagation can induce a neutrino spin-flip, similar to the one induced by a transverse magnetic field.