Multipole analysis of IceCube data to search for dark matter accumulated in the Galactic halo

Journal article

Dark matter which is bound in the Galactic halo might self-annihilate and produce a flux of stable final state particles, e.g. high energy neutrinos. These neutrinos can be detected with IceCube, a cubic-kilometer sized Cherenkov detector. Given IceCube's large field of view, a characteristic anisotropy of the additional neutrino flux is expected. In this paper we describe a multipole method to search for such a large-scale anisotropy in IceCube data. This method uses the expansion coefficients of a multipole expansion of neutrino arrival directions and incorporates signal-specific weights for each expansion coefficient. We apply the technique to a high-purity muon neutrino sample from the Northern Hemisphere. The final result is compatible with the null-hypothesis. As no signal was observed, we present limits on the self-annihilation cross-section averaged over the relative velocity distribution $<\sigma v>$ down to $1.9\cdot 10^{-23}\,\mathrm{cm}^3\mathrm{s}^{-1}$ for a dark matter particle mass of $700\,\mathrm{GeV}$ to $1000\,\mathrm{GeV}$ and direct annihilation into $\nu\bar{\nu}$. The resulting exclusion limits come close to exclusion limits from $\gamma$-ray experiments, that focus on the outer Galactic halo, for high dark matter masses of a few TeV and hard annihilation channels.

Authors: Aartsen, MG; Sarkar, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Springer Berlin Heidelberg
• Journal: European Physical Journal C
• Volume: C75
• Issue: 1
• Pages: 20-20
• Publication date: 2015-01-20
• Acceptance date: 2014-12-11
• DOI: 10.1140/epjc/s10052-014-3224-5
• EISSN: 1434-6052
• ISSN: 1434-6044
• Keywords: astro-ph.HE; astro-ph.GA; SBTMR