125 research outputs found
Antimatter from supersymmetric dark matter
We propose low-energy antideuterons in cosmic rays as a new possible
signature for indirect detection of supersymmetric dark matter.
Since the energy spectrum of the antiproton secondary component is still
spoilt by considerable theoretical uncertainties, looking for low-energy
antideuterons seems a plausible alternative.
We apply our calculation to the AMS experiment, when mounted on the
International Spatial Station. If a few low-energy antideuterons will be
discovered by AMS, this should be seriously taken as a clue for the existence
of relic, massive neutralinos in the dark halo of our Galaxy.Comment: 8 pages, 8 figures, Talk presented at the 4th International Symposium
On Sources And Detection Of Dark Matter In The Universe (DM 2000), Marina del
Rey, California, 23-25 Feb. 200
General Analysis of Antideuteron Searches for Dark Matter
Low energy cosmic ray antideuterons provide a unique low background channel
for indirect detection of dark matter. We compute the cosmic ray flux of
antideuterons from hadronic annihilations of dark matter for various Standard
Model final states and determine the mass reach of two future experiments
(AMS-02 and GAPS) designed to greatly increase the sensitivity of antideuteron
detection over current bounds. We consider generic models of scalar, fermion,
and massive vector bosons as thermal dark matter, describe their basic features
relevant to direct and indirect detection, and discuss the implications of
direct detection bounds on models of dark matter as a thermal relic. We also
consider specific dark matter candidates and assess their potential for
detection via antideuterons from their hadronic annihilation channels. Since
the dark matter mass reach of the GAPS experiment can be well above 100 GeV, we
find that antideuterons can be a good indirect detection channel for a variety
of thermal relic electroweak scale dark matter candidates, even when the rate
for direct detection is highly suppressed.Comment: 44 pages, 15 Figure
T-cell Subset Regulation in Atopy
Presentation of processed allergen by antigen-presenting cells to T-helper (Th) lymphocytes, which is influenced costimulatory signals, cytokines, chemokines, and regulatory T cells (Tregs), determines the development of different types of T-cell immunity. The discovery of Tregs revolutionized the primary concepts of immune regulation interpreted within the framework of a binary Th1/Th2 paradigm. Tregs play a central role in the maintenance of peripheral homeostasis, the establishment of controlled immune responses, and the inhibition of allergen-specific effector cells. Recently, some other T-cell subsets appeared, including Th17 and Th9 cells, which control local tissue inflammation through upregulation of proinflammatory cytokines and chemokines. This review aims to discuss our understanding of the T-cell subset reciprocal interaction in atopy
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