Sensitivity of Neutrino Mass Experiments to the Cosmic Neutrino Background

TL;DR

This paper investigates how the KATRIN neutrino experiment could detect the Cosmic Neutrino Background by measuring relic neutrino density, offering insights into cosmological models and neutrino properties.

Contribution

It analyzes KATRIN's potential sensitivity to the Cosmic Neutrino Background and establishes its capability to test over-density ratios of relic neutrinos.

Findings

KATRIN can detect a relic neutrino over-density ratio of 2.0x10^9.

The experiment's sensitivity can challenge certain cosmological models.

KATRIN's measurements could provide new constraints on neutrino properties.

Abstract

The KATRIN neutrino experiment is a next-generation tritium beta decay experiment aimed at measuring the mass of the electron neutrino to better than 200 meV at 90% C.L. Due to its intense tritium source, KATRIN can also serve as a possible target for the process of neutrino capture, {\nu}e +3H \to 3He+ + e-. The latter process, possessing no energy threshold, is sensitive to the Cosmic Neutrino Background (C{\nu}B). In this paper, we explore the potential sensitivity of the KATRIN experiment to the relic neutrino density. The KATRIN experiment is sensitive to a C{\nu}B over-density ratio of 2.0x 10^9 over standard concordance model predictions (at 90% C.L.), addressing the validity of certain speculative cosmological models.