Prospects of indirect searches for dark matter annihilations in the earth with ICAL@INO

TL;DR

This paper evaluates ICAL@INO's potential to detect muon signals from WIMP annihilations in Earth's core, providing competitive sensitivity limits on WIMP-nucleon interactions for masses between 10-100 GeV.

Contribution

It presents the first detailed sensitivity analysis of ICAL@INO for indirect dark matter detection via Earth-centered WIMP annihilations, surpassing existing experimental limits.

Findings

ICAL can set more stringent limits on WIMP-nucleon cross-sections than current experiments.

Resonance effects at ~52 GeV enhance detection sensitivity.

Sensitivity limits are approximately 1.02×10^{-44} cm^2 for τ+τ− channel.

Abstract

We study the prospects of detecting muon events at the upcoming Iron CALorimeter (ICAL) detector to be built at the proposed India-based Neutrino Observatory (INO) facility due to neutrinos arising out of annihilation of Weakly Interactive Massive Particles (WIMP) in the centre of the earth. The atmospheric neutrinos coming from the direction of earth core presents an irreducible background. We consider 50kt $\times$ 10 years of ICAL running and WIMP masses between 10-100 GeV and present 90 \% C.L. exclusion sensitivity limits on $\sigma_{SI}$ which is the WIMP-nucleon Spin Independent (SI) interaction cross-section. The expected sensitivity limits calculated for ICAL for the WIMP annihilation in the earth are more stringent than the limits obtained by any other indirect detection experiment. For a WIMP mass of ~$52.14 \textup{ GeV}$, where the signal fluxes are enhanced due to resonance capture of WIMP in earth due to Fe nuclei, the sensitivity limits, assuming 100\% branching ratio for each channel, are : $\sigma_{SI} =1.02\times 10^{-44}~cm^2$ for the $\tau^{+} \tau^{-}$ channel and $\sigma_{SI} =5.36\times 10^{-44} ~cm^2$ for the $b ~\bar{b}$ channel.