9,404 research outputs found
Which fraction of the measured cosmic-ray antiprotons might be due to neutralino annihilation in the galactic halo?
We analyze the data of low-energy cosmic-ray antiproton spectrum, recently
published by the BESS Collaboration, in terms of newly calculated fluxes for
secondary antiprotons and for a possible contribution of an exotic signal due
to neutralino annihilation in the galactic halo. We single out the relevant
supersymmetric configurations and discuss their explorability with experiments
of direct search for particle dark matter and at accelerators. We discuss how
future measurements with the Alpha Magnetic Spectrometer (AMS) on the Shuttle
flight may disentangle the possible neutralino-induced contribution from the
secondary one.Comment: 25 pages, ReVTeX, 18 figures (high resolution figures available upon
request
Relic neutralinos and the two dark matter candidate events of the CDMS II experiment
The CDMS Collaboration has presented its results for the final exposure of
the CDMS II experiment and reports that two candidate events for dark matter
would survive after application of the various discrimination and subtraction
procedures inherent in their analysis. We show that a population of relic
neutralinos, which was already proved to fit the DAMA/LIBRA data on the annual
modulation effect, could naturally explain the two candidate CDMS II events, if
these are actually due to a dark matter signal.Comment: 3 pages, 3 figure
Positrons from dark matter annihilation in the galactic halo: uncertainties
Indirect detection signals from dark matter annihilation are studied in the
positron channel. We discuss in detail the positron propagation inside the
galactic medium: we present novel solutions of the diffusion and propagation
equations and we focus on the determination of the astrophysical uncertainties
which affect the positron dark matter signal. We show that, especially in the
low energy tail of the positron spectra at Earth, the uncertainty is sizeable
and we quantify the effect. Comparison of our predictions with current
available and foreseen experimental data are derived.Comment: 4 pages, 4 figures, Proc. of the 30th International Cosmic Ray
Conference, July 3 - 11, 2007, Merida, Yucatan, Mexico (ICRC07
Positrons from dark matter annihilation in the galactic halo: theoretical uncertainties
Indirect detection signals from dark matter annihilation are studied in the
positron channel. We discuss in detail the positron propagation inside the
galactic medium: we present novel solutions of the diffusion and propagation
equations and we focus on the determination of the astrophysical uncertainties
which affect the positron dark matter signal. We find dark matter scenarios and
propagation models that nicely fit existing data on the positron fraction.
Finally, we present predictions both on the positron fraction and on the flux
for already running or planned space experiments, concluding that they have the
potential to discriminate a possible signal from the background and, in some
cases, to distinguish among different astrophysical propagation models.Comment: 22 pages, 15 figures. A few comments and references adde
Interpretation of AMS-02 electrons and positrons data
We perform a combined analysis of the recent AMS-02 data on electrons,
positrons, electrons plus positrons and positron fraction, in a self-consistent
framework where we realize a theoretical modeling of all the astrophysical
components that can contribute to the observed fluxes in the whole energy
range. The primary electron contribution is modeled through the sum of an
average flux from distant sources and the fluxes from the local supernova
remnants in the Green catalog. The secondary electron and positron fluxes
originate from interactions on the interstellar medium of primary cosmic rays,
for which we derive a novel determination by using AMS-02 proton and helium
data. Primary positrons and electrons from pulsar wind nebulae in the ATNF
catalog are included and studied in terms of their most significant (while
loosely known) properties and under different assumptions (average contribution
from the whole catalog, single dominant pulsar, a few dominant pulsars). We
obtain a remarkable agreement between our various modeling and the AMS-02 data
for all types of analysis, demonstrating that the whole AMS-02 leptonic data
admit a self-consistent interpretation in terms of astrophysical contributions.Comment: 33 pages, 26 figures and 4 tables, v2: accepted for publication in
JCAP, minor changes relative to v
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