Licentiate Thesis: Indirect Searches for Galactic Dark Matter with IceCube-DeepCore and PINGU
Thursday 12 June 2014
to 15:15 at
Martin Wolf (Department of Physics, Stockholm University)
The cubic-kilometer sized IceCube neutrino observatory is buried deep in the glacial ice at the Earth’s South Pole. Its low-energy extension array DeepCore enables physicists to search indirectly for light Dark Matter (DM) particles with masses as low as tens of GeV/ c² situated within our home galaxy, the Milky Way. GeV neutrinos could be produced through DM particle annihilations, propagating to the Earth where they could be detected by IceCube.
This licentiate thesis presents a search for Weakly Interacting Massive Particles (WIMPs) with masses as low as 30 GeV/c² in the Galactic center (GC) using the 79-string configuration of the IceCube neutrino detector. Data from 319.7 live-days have been analyzed using a cut-and count analysis approach, and found to be consistent with the background-only hypothesis with expected background from atmospheric muons and neutrinos. Thus, upper limits were set on the velocity averaged DM annihilation cross-section.
The Precision IceCube Next Generation Upgrade (PINGU) as a possible future neutrino detector within DeepCore would reduce the neutrino energy detection threshold to a few GeV.
In addition to the data analysis with DeepCore, a sensitivity study has been conducted to investigate the performance of PINGU for indirect DM searches in the GC and the Sun. In the Sun WIMPs could be gravitationally captured through elastic scattering off nucleons. In this
thesis, we derive PINGU sensitivities for the velocity averaged DM annihilation cross-section of WIMPs in the GC, and for the Spin-Dependent (SD) and Spin-Independent (SI) WIMPproton scattering cross-sections, under the assumption of thermodynamic equilibrium between the WIMP capturing and annihilation rate in the Sun.