High energy neutrinos from neutralino annihilations in the Sun

TL;DR

This paper calculates high-energy neutrino signals from neutralino annihilations in the Sun, considering detailed particle interactions and neutrino propagation effects, to evaluate detection prospects in IceCube and KM3 experiments.

Contribution

It provides a comprehensive calculation of neutrino fluxes from neutralino annihilations, including spin effects and propagation, focusing on the supergravity Focus Point region.

Findings

High neutrino fluxes are predicted for neutralino masses above M_Z up to 400 GeV.

Muon signals in IceCube can be distinguished from background in the Focus Point region.

Spin-dependent capture rates are significantly enhanced, increasing detection prospects.

Abstract

Neutralino annihilations in the Sun to weak boson and top quark pairs lead to high-energy neutrinos that can be detected by the IceCube and KM3 experiments in the search for neutralino dark matter. We calculate the neutrino signals from real and virtual WW, ZZ, Zh, and $t \bar t$ production and decays, accounting for the spin-dependences of the matrix elements, which can have important influences on the neutrino energy spectra. We take into account neutrino propagation including neutrino oscillations, matter-resonance, absorption, and nu_tau regeneration effects in the Sun and evaluate the neutrino flux at the Earth. We concentrate on the compelling Focus Point (FP) region of the supergravity model that reproduces the observed dark matter relic density. For the FP region, the lightest neutralino has a large bino-higgsino mixture that leads to a high neutrino flux and the spin-dependent neutralino capture rate in the Sun is enhanced by 10^3 over the spin-independent rate. For the standard estimate of neutralino captures, the muon signal rates in IceCube are identifiable over the atmospheric neutrino background for neutralino masses above M_Z up to 400 GeV.