Neutrinos from Inert Doublet Dark Matter

We investigate the signatures of neutrinos produced in the annihilation of WIMP dark matter in the Earth, the Sun and at the Galactic centre within the framework of the Inert Doublet Model and extensions. We consider a dark matter candidate, that we take to be one of the neutral components of an extra Higgs doublet, in three distinct mass ranges, which have all been shown previously to be consistent with both WMAP abundance and direct detection experiments exclusion limits. Specifically, we consider a light WIMP with mass between 4 and 8 GeV (low), a WIMP with mass around 60-70 GeV (middle) and a heavy WIMP with mass above 500 GeV (high). In the first case, we show that capture in the Sun may be constrained using Super-Kamiokande data. In the last two cases, we argue that indirect detection through neutrinos is challenging but not altogether excluded. For middle masses, we try to make the most benefit of the proximity of the so-called 'iron resonance' that might enhance the capture of the dark matter candidate by the Earth. The signal from the Earth is further enhanced if light right-handed Majorana neutrinos are introduced, in which case the scalar dark matter candidate may annihilate into pairs of mono-energetic neutrinos. In the case of high masses, detection of neutrinos from the Galactic centre might be possible, provided the dark matter abundance is substantially boosted.
Comment: 25 pages, 13 figures; v2: minor changes, more detailed discussion on capture, conclusions unchanged, matches published version (JCAP)