Multi-year search for dark matter annihilations in the Sun with the AMANDA-II and IceCube detectors

TL;DR

This study searches for dark matter annihilation signals in the Sun using AMANDA-II and IceCube detectors over multiple years, setting new limits on neutralino properties and surpassing previous constraints.

Contribution

It provides the first combined multi-year analysis of neutrino data from AMANDA-II and IceCube, improving limits on dark matter annihilation and neutralino cross sections.

Findings

No excess neutrinos detected over background.

Set the most stringent spin-dependent cross section limits above 200 GeV.

Extended neutralino mass sensitivity down to 50 GeV.

Abstract

A search for an excess of muon-neutrinos from dark matter annihilations in the Sun has been performed with the AMANDA-II neutrino telescope using data collected in 812 days of livetime between 2001 and 2006 and 149 days of livetime collected with the AMANDA-II and the 40-string configuration of IceCube during 2008 and early 2009. No excess over the expected atmospheric neutrino background has been observed. We combine these results with the previously published IceCube limits obtained with data taken during 2007 to obtain a total livetime of 1065 days. We provide an upper limit at 90% confidence level on the annihilation rate of captured neutralinos in the Sun, as well as the corresponding muon flux limit at the Earth, both as functions of the neutralino mass in the range 50 GeV-5000 GeV. We also derive a limit on the neutralino-proton spin-dependent and spin-independent cross section. The limits presented here improve the previous results obtained by the collaboration between a factor of two and five, as well as extending the neutralino masses probed down to 50 GeV. The spin-dependent cross section limits are the most stringent so far for neutralino masses above 200 GeV, and well below direct search results in the mass range from 50 GeV to 5 TeV.