Annihilation Of Neutralino Dark Matter Research Articles

Expected enhancement of the primary antiproton flux at the solar minimum

We calculate the solar-modulated energy spectra of cosmic-ray antiprotons ( p 's) from two candidate primary sources, i.e., evaporating primordial black holes and the annihilation of neutralino dark matter, as well as for the secondary p 's produced by cosmic-ray interactions with interstellar gas. A large enhancement toward the solar minimum phase emerges in the low-energy flux of p 's from the primary sources, whereas the flux of the secondary p 's, falling steeply below 2 GeV, does not significantly vary. This enables us to conduct a very sensitive search for primary p components by precisely measuring the p spectrum, especially at low energies, throughout the forthcoming solar minimum phase.

Assessing ultrasonic arrays for imaging tissue properties: R. Martin Arthur, Michael L. Sieger and Donald W. Stein, Jr., Biomedical Computer Laboratory and Department of Electrical Engineering, Washington University, St. Louis, MO 63130

The recent commissioning of the full DeepCore sub-array, a low-energy extension of the IceCube neutrino observatory, offers opportunities for neutrino physics in the energy region of 10 GeV to 1 TeV. The improved energy reach, use of the surrounding IceCube detector as an active veto and immense size of DeepCore will produce one of the largest all-sky neutrino datasets ever acquired. DeepCore will provide sensitivity to neutrinos from possible neutralino dark matter annihilations in the Earth, Sun and galactic center, down to neutralino masses in the region of ∼ 50 GeV. Tens of thousands of atmospheric neutrinos will be detected annually after oscillating over a baseline of up to one Earth diameter, opening the possibilities for muon neutrino disappearance and tau neutrino appearance measurements.