27,624 research outputs found
Indirect Detection Signatures for the Origin of Asymmetric Dark Matter
We study the decay signatures of Asymmetric Dark Matter (ADM) via higher
dimension operators which are responsible for generating the primordial dark
matter (DM) asymmetry. Since the signatures are sensitive both to the nature of
the higher dimension operator generating the DM asymmetry and to the sign of
the baryon or lepton number that the DM carries, indirect detection may provide
a window into the nature of the mechanism which generates the DM asymmetry. We
consider in particular dimension-6 fermionic operators of the form , where (or operators related through a Hermitian conjugate) with
the scale around or just below the GUT scale. We derive constraints on ADM
particles both in the natural mass range (around a few GeV), as well as in the
range between 100 GeV to 10 TeV. For light ADM, we focus on constraints from
both the low energy gamma ray data and proton/anti-proton fluxes. For heavy
ADM, we consider -rays and proton/anti-proton fluxes, and we fit
data from AMS-02 and H.E.S.S. (neglecting the Fermi charged particle
fluxes which disagree with AMS-02 below 100 GeV). We show that, although the
best fit regions from electron/positron measurement are still in tension with
other channels on account of the H.E.S.S. measurement at high energies,
compared to an ordinary symmetric dark matter scenario, the decay of DM with a
primordial asymmetry reduces the tension. Better measurement of the flux at
high energy will be necessary to draw a definite conclusion about the viability
of decaying DM as source for the signals.Comment: Constraint from H.E.S.S. for heavy ADM scenario is included.
Constraint from anti-proton flux for light ADM scenario is included. Matched
to the version of publicatio
Gauge Theory Model of the Neutrino and New Physics Beyond the Standard Model
Majorana features of neutrinos and SO(3) gauge symmetry of three families
enable us to construct a gauge model of neutrino for understanding naturally
the observed smallness of neutrino masses and the nearly tri-bimaximal neutrino
mixing when combining together with the mechanism of approximate global U(1)
family symmetry. The vacuum structure of SO(3) symmetry breaking is found to
play an important role. The mixing angle and CP-violating phases
governed by the vacuum of spontaneous symmetry breaking are in general non-zero
and testable experimentally at the allowed sensitivity. The model predicts the
existence of vector-like SO(3) triplet charged leptons and vector-like SO(3)
triplet Majorana neutrinos as well as SO(3) tri-triplet Higgs bosons, some of
them can be light and explored at the colliders LHC and ILC.Comment: 15 pages, only typos in table 1 corrected in this replaced versio
Sampling Sparse Signals on the Sphere: Algorithms and Applications
We propose a sampling scheme that can perfectly reconstruct a collection of
spikes on the sphere from samples of their lowpass-filtered observations.
Central to our algorithm is a generalization of the annihilating filter method,
a tool widely used in array signal processing and finite-rate-of-innovation
(FRI) sampling. The proposed algorithm can reconstruct spikes from
spatial samples. This sampling requirement improves over
previously known FRI sampling schemes on the sphere by a factor of four for
large . We showcase the versatility of the proposed algorithm by applying it
to three different problems: 1) sampling diffusion processes induced by
localized sources on the sphere, 2) shot noise removal, and 3) sound source
localization (SSL) by a spherical microphone array. In particular, we show how
SSL can be reformulated as a spherical sparse sampling problem.Comment: 14 pages, 8 figures, submitted to IEEE Transactions on Signal
Processin
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