Direct Neutrino Mass Experiments and Exotic Charged Current Interactions

TL;DR

This paper investigates how exotic charged current interactions could distort the electron energy spectrum in tritium decay, impacting neutrino mass measurements in experiments like KATRIN, considering both sub-eV and keV neutrino masses.

Contribution

It provides a comprehensive relativistic analysis of exotic interactions' effects on the electron spectrum, including all possible new physics contributions.

Findings

Exotic interactions can cause significant distortions in the energy spectrum.

Full spectrum access enhances sensitivity to new physics effects.

Results are relevant for current and future neutrino mass experiments.

Abstract

We study the effect of exotic charged current interactions on the electron energy spectrum in tritium decay, focussing on the KATRIN experiment and a possible modified setup that has access to the full spectrum. Both sub-eV and keV neutrino masses are considered. We perform a fully relativistic calculation and take all possible new interactions into account, demonstrating the possible sizable distortions in the energy spectrum.