63 research outputs found
Diffuse inverse Compton and synchrotron emission from dark matter annihilations in galactic satellites
Annihilating dark matter particles produce roughly as much power in electrons
and positrons as in gamma ray photons. The charged particles lose essentially
all of their energy to inverse Compton and synchrotron processes in the
galactic environment. We discuss the diffuse signature of dark matter
annihilations in satellites of the Milky Way (which may be optically dark with
few or no stars), providing a tail of emission trailing the satellite in its
orbit. Inverse Compton processes provide X-rays and gamma rays, and synchrotron
emission at radio wavelengths might be seen. We discuss the possibility of
detecting these signals with current and future observations, in particular
EGRET and GLAST for the gamma rays.Comment: 13 pages, 5 figure
Gamma rays from dark matter annihilation in the Draco and observability at ARGO
The CACTUS experiment recently observed a gamma ray excess above 50 GeV from
the direction of the Draco dwarf spheroidal galaxy. Considering that Draco is
dark matter dominated the gamma rays may be generated through dark matter
annihilation in the Draco halo. In the framework of the minimal supersymmetric
extension of the standard model we explore the parameter space to account for
the gamma ray signals at CACTUS. We find that the neutralino mass is
constrained to be approximately in the range between 100 GeV ~ 400 GeV and a
sharp central cuspy of the dark halo profile in Draco is necessary to explain
the CACTUS results. We then discuss further constraints on the supersymmetric
parameter space by observations at the ground based ARGO detector. It is found
that the parameter space can be strongly constrained by ARGO if no excess from
Draco is observed above 100 GeV.Comment: 15 pages, 4 figure
The and Decays Revisited
The rare and decays are calculated
in different schemes, which are seen to be essentially equivalent to and
produce the same results as conventional Vector-Meson Dominance. We obtain the
theoretical predictions
and in agreement
with recent experimental data.Comment: 10 pages, LATEX (revised version for recent experimental data
Geochemistry of Upper Ordovician metabentonites and their cognate apatite microphenocrysts from Norway and Sweden
The Upper Ordovician-Lower Silurian stratigraphic seccession in the Caledonian foreland basin of central Sweden: relationship to the Hirnatian glacial interval
The Upper Ordovician Guttenberg d13C excursion (GICE) in North America and Baltoscandia: Occurrence, chronosratigraphic significance and paleoenvironmental relationships
First record of the Ordovician Guttenberg d13C excursion (GICE) in New York state and Ontario: Local and regional chronostratigraphic implications
Darriwilian (Middle Ordovician) chemostratigraphy linked to graptolite, conodont and trilobite biostratigraphy in the Fågelsång-3 drill core, Scania, Sweden
Chitinozoan biostratigraphy in the Haljala Regional Stage, Upper Ordovician: a high-resolution approach from NE Estonia
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