Neutrino loops from neutrino mixing

TL;DR

This paper demonstrates how neutrino mixing can soften ultraviolet divergences in neutrino loops, resulting in finite amplitudes that could impact dark matter interactions with the Standard Model, exemplified through a one-loop W-boson coupling.

Contribution

It introduces a novel mechanism where neutrino mixing leads to UV-finite neutrino loop amplitudes, with implications for dark matter interactions.

Findings

Neutrino mixing softens UV behavior of neutrino loops.

Neutrino loops can produce finite, anomaly-like amplitudes.

Potential significance for dark matter coupling to Standard Model.

Abstract

We show how neutrino mixing leads to a softening of the UV behavior of neutrino loops, and can give rise to anomaly-like, but manifestly UV finite amplitudes. This mechanism may be of special significance for the coupling of dark matter-like particles to the Standard Model, as we illustrate with a one-loop example involving the coupling to $W$-bosons.