Search for Radiative Decays of Cosmic Background Neutrino using Cosmic Infrared Background Energy Spectrum

TL;DR

This study searches for neutrino radiative decays by analyzing the cosmic infrared background spectrum, setting lifetime limits for neutrino decay and assessing the feasibility of future observations.

Contribution

It introduces a method to constrain neutrino radiative decay lifetime using cosmic infrared background data and compares experimental limits with theoretical predictions.

Findings

Lower limit of neutrino lifetime between 3.1 and 3.8 trillion years.

Predicted minimum neutrino lifetime in the left-right symmetric model is 1.5 x 10^{17} years.

Feasibility analysis for detecting neutrino decay with extremely long lifetimes.

Abstract

We propose to search for the neutrino radiative decay by fitting a photon energy spectrum of the cosmic infrared background to a sum of the photon energy spectrum from the neutrino radiative decay and a continuum. By comparing the present cosmic infrared background energy spectrum observed by AKARI and Spitzer to the photon energy spectrum expected from neutrino radiative decay with a maximum likelihood method, we obatined a lifetime lower limit of $3.1 \times 10^{12}$ to $3.8 \times 10^{12}$ years at 95% confidence level for the third generation neutrino $\nu_3$ in the $\nu_3$ mass range between 50 \mmev and 150 \mmev under the present constraints by the neutrino oscillation measurements. In the left-right symmetric model, the minimum lifetime of $\nu_3$ is predicted to be $1.5 \times 10^{17}$ years for $m_3$ of 50 \mmev. We studied the feasibility of the observation of the neutrino radiative decay with a lifetime of $1.5 \times 10^{17}$ years, by measuring a continuous energy spectrum of the cosmic infrared background.