The CACTUS atmospheric Cherenkov telescope collaboration recently reported a gamma-ray excess from the Draco dwarf spheroidal galaxy. Draco features a very low gas content and a large mass-tolight ratio, suggesting as a possible explanation annihilation of weakly interacting massive particles (WIMPs) in the Draco dark-matter halo. We show that with improved angular resolution, future measuremen...

This paper is a review of low-energy positron interactions with atoms and molecules. Processes of interest include elastic scattering, electronic and vibrational excitation, ionization, positronium formation and annihilation. An overview is presented of the currently available theoretical and experimental techniques to study these phenomena, including the use of trap-based positron beam sources...

It has been proposed that during the formation of the first generation stars there might be a “dark star” phase in which the power of the star comes from dark matter annihilation. The adiabatic contraction process to form the dark star would result in a highly concentrated density profile of the host halo at the same time, which may give enhanced indirect detection signals of dark matter. In th...

We estimate the ux of cosmic-ray antiprotons expected from the annihilation of neutralinos in the galactic halo. The antiproton signal may ooer an important alternative detection scheme in the case that neutralino annihilation proceeds mainly to the two-gluon nal state.

We establish a useful identity for intertwining a creation or annihilation operator with the heat kernel of a self-interacting bosonic field theory. I Background Consider creation operators a(f) and annihilation operators a(h), both linear in their respective test functions f, h ∈ L(R, dx), acting on the Fock Hilbert space H, and satisfying the canonical commutation relations [a(h), a(f)] = 〈

If Weakly Interacting Massive Particles (WIMPs) are the Dark Matter in the Galaxy, they can be detected directly in nuclear-recoil experiments or indirectly by observing their annihilation products. Limits obtained by the two techniques can be compared but this comparison requires some hypothesis about the WIMPs cross sections on nuclei and their annihilation branching ratios into neutrinos.

ABSTRACT: We investigate the dynamics of monopole annihilation by the LangackerPi mechanism. We find that considerations of causality, flux-tube energetics and the friction from Aharonov-Bohm scattering suggest that the monopole annihilation is most efficient if electromagnetism is spontaneously broken at the lowest temperature (Tem ≈ 106 GeV) consistent with not having the monopoles dominate t...

Positron annihilation radiation from the Galaxy has been observed by the OSSE, SMM and TGRS instruments. Improved spectral modeling of OSSE observations has allowed studies of the distribution of both positron annihilation radiation components, the narrow line emission at 511 keV and the positronium continuum emission. The results derived for each individual annihilation component are then comp...