96 research outputs found
Neutrino physics with the Baksan Underground Scintillation Telescope
The neutrino experiment at the Baksan Underground Scintillation Telescope is operating for 35 years. We present an updated analysis of observed upward through-going muons in searches for a signal from dark matter annihilations in the Sun and the astrophysical local sources
Prospects For Detecting Dark Matter With Neutrino Telescopes In Light Of Recent Results From Direct Detection Experiments
Direct detection dark matter experiments, lead by the CDMS collaboration,
have placed increasingly stronger constraints on the cross sections for elastic
scattering of WIMPs on nucleons. These results impact the prospects for the
indirect detection of dark matter using neutrino telescopes. With this in mind,
we revisit the prospects for detecting neutrinos produced by the annihilation
of WIMPs in the Sun. We find that the latest bounds do not seriously limit the
models most accessible to next generation kilometer-scale neutrino telescopes
such as IceCube. This is largely due to the fact that models with significant
spin-dependent couplings to protons are the least constrained and, at the same
time, the most promising because of the efficient capture of WIMPs in the Sun.
We identify models where dark matter particles are beyond the reach of any
planned direct detection experiments while within reach of neutrino telescopes.
In summary, we find that, even when contemplating recent direct detection
results, neutrino telescopes still have the opportunity to play an important as
well as complementary role in the search for particle dark matter.Comment: 13 pages, 6 figure
Standard and exotic interpretations of the atmospheric neutrino data
The present status of some theoretical interpretations of the atmospheric
neutrino deficit is briefly discussed. Specifically, we show the results for
the FC mechanism and for the standard oscillation hypothesis, both in the
active and in the sterile channels. All these mechanisms are able to fit the
present data to a good statistical level. Among them, the nu_mu --> nu_tau
oscillation is certainly the best explanation to the atmospheric neutrino
deficit, providing a remarkably good agreement with the data.Comment: 3 pages, 2 figures, talk delivered at the 6th International Workshop
on Topics in Astroparticle and Underground Physics (TAUP 99), September 1999,
Paris, (to appear in the Conference Proceedings, Nucl. Phys. B (Proc.
Suppl.), eds. M. Froissart, J. Dumarchez and D. Vignaud
Angular distribution of muons produced by cosmic ray neutrinos in rock
Measurement of the upgoing muons flux, produced by cosmic ray neutrinos is aiming at: (1) search for neutrino oscillation; (2); search for extraterrestrial neutrinos from local sources; and (3); search for any hypothetical neutral penetrating radiation different from neutrinos. Experimental data of the Baksan underground telescope on intensity of upward muons for three years of living time, was analyzed having in mind mainly neutrino oscillation
Annihilation of NMSSM neutralinos in the Sun and neutrino telescope limits
We investigate neutralino dark matter in the framework of NMSSM performing a
scan over its parameter space and calculating neutralino capture and
annihilation rates in the Sun. We discuss the prospects of searches for
neutralino dark matter in neutrino experiments depending on neutralino content
and its main annihilation channel. We recalculate the upper limits on
neutralino-proton elastic cross sections directly from neutrino telescopes
upper bounds on annihilation rates in the Sun. This procedure has advantages as
compared with corresponding recalcalations from the limits on muon flux,
namely, it is independent on details of the experiment and the recalculation
coefficients are universal for any kind of WIMP dark matter models. We derive
90% c.l. upper limits on neutralino-proton cross sections from the results of
the Baksan Underground Scintillator Telescope.Comment: 28 pages, 16 figures, accepted for publication in JCAP, references
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The New DAMA Dark-Matter Window and Energetic-Neutrino Searches
Recently, the DAMA/LIBRA collaboration has repeated and reinforced their
claim to have detected an annual modulation in their signal rate, and have
interpreted this observation as evidence for dark-matter particles at the 8.2
sigma confidence level. Furthermore, it has also been noted that the effects of
channeling may enable a WIMP that scatters elastically via spin-independent
interactions from nuclei to produce the signal observed by DAMA/LIBRA without
exceeding the limits placed by CDMS, XENON, CRESST, CoGeNT and other
direct-detection experiments. To accommodate this signal, however, the mass of
the responsible dark-matter particle must be relatively light, m_{DM} \lsim 10
GeV. Such dark-matter particles will become captured by and annihilate in the
Sun at very high rates, leading to a potentially large flux of GeV-scale
neutrinos. We calculate the neutrino spectrum resulting from WIMP annihilations
in the Sun and show that existing limits from Super-Kamiokande can be used to
close a significant portion of the DAMA region, especially if the dark-matter
particles produce tau leptons or neutrinos in a sizable fraction of their
annihilations. We also determine the spin-dependent WIMP-nuclei
elastic-scattering parameter space consistent with DAMA. The constraints from
Super-Kamiokande on the spin-dependent scenario are even more severe--they
exclude any self-annihilating WIMP in the DAMA region that annihilates 1% of
the time or more to any combination of neutrinos, tau leptons, or charm or
bottom quarks.Comment: 13 pages, 7 figure
An Inverted Mass Hierarchy for Hot Dark Matter and the Solar Neutrino Problem.
The cosmological model in which 20% of the dark matter is shared by two
nearly equal mass neutrinos fits the structure of the universe on all scales.
This has been motivated a - oscillation explanation of the
deficit of atmospheric muon neutrinos. If the observed ratio of atmospheric
to has an alternative explanation, the cosmological model can
be retained if the deficit of solar neutrinos is explained by
- oscillation. In this case an inverted mass hierarchy is
required with eV.
We show that if there exists an symmetry in nature, both the
near mass degeneracy of \nue\ and \nut\ as well as the consistency of the above
values for neutrino masses with the negative results for neutrinoless double
beta decay search experiments are easily understood. We show that this symmetry
implemented in the context of a high-scale left-right symmetric theory with the
see-saw mechanism can lead to a simple theoretical understanding of the desired
form of the mass matrix.Comment: Tex file; no figures; 10 page
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