Sensitivity to neutrino decay with atmospheric neutrinos at INO

TL;DR

This paper investigates the ability of the INO's ICAL detector to detect invisible neutrino decay using atmospheric neutrinos, demonstrating significantly improved constraints on neutrino lifetime compared to previous experiments.

Contribution

It provides a comprehensive three-generation analysis including earth matter effects to constrain the neutrino decay lifetime with atmospheric neutrinos at INO.

Findings

Constrains neutrino $ u_3$ lifetime to $ au_3/m_3>1.51\times10^{-10}$ s/eV at 90% C.L.

ICAL can improve bounds on neutrino decay by two orders of magnitude over MINOS.

Studies impact of decay on precision of $ heta_{23}$ and $| riangle m^2_{32}|$ measurements.

Abstract

Sensitivity of the magnetised Iron CALorimeter (ICAL) detector at the proposed India-based Neutrino Observatory (INO) to invisible decay of the mass eigenstate $\nu_3$ using atmospheric neutrinos is explored. A full three-generation analysis including earth matter effects is performed in a framework with both decay and oscillations. The wide energy range and baselines offered by atmospheric neutrinos are shown to be excellent for constraining the $\nu_3$ lifetime. We find that with an exposure of 500 kton-yr the ICAL atmospheric experiment could constrain the $\nu_3$ lifetime to $\tau_3/m_3>1.51\times10^{-10}$ s/eV at the 90\% C.L. This is two orders of magnitude tighter than the bound from MINOS. The effect of invisible decay on the precision measurement of $\theta_{23}$ and $|\Delta{m^2_{32}}|$ is also studied.