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Résumé |
In this talk, we discuss the implications of the premise that any new,
relativistic, highly energetic neutral particle that interacts with quarks
and gluons would create cascade-like events in the IceCube (IC) detector
which would be observationally indistinguishable from neutral current
deep-inelastic (DIS) scattering events due to neutrinos. Consequently, one
reason for deviations, breaks or excesses in the expected astrophysical
power-law neutrino spectrum could be the flux of such a particle.
Motivated by features in the recent 1347-day IceCube high energy starting
event (HESE) data, we focus on particular boosted dark matter (\chi)
related realizations of this premise, where \chi is assumed to be much
lighter than, and the result of, the slow decay of a massive scalar (\phi
) which constitutes a major fraction of the Universe’s dark matter (DM).
We show that this hypothesis, coupled with a standard power-law
astrophysical neutrino flux is capable of providing very good fits to the
present data, along with a possible explanation of other features in the
HESE sample : ie, a) the paucity of events beyond 2 PeV b) a spectral
feature resembling a dip in the 400 TeV - 1 PeV region and c) an excess in
the 50-100 TeV region. We also consider constraints from diffuse gamma ray
backgrounds and find that it is indeed very restrictive. |
