130 research outputs found
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
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
Determining Supersymmetric Parameters With Dark Matter Experiments
In this article, we explore the ability of direct and indirect dark matter
experiments to not only detect neutralino dark matter, but to constrain and
measure the parameters of supersymmetry. In particular, we explore the
relationship between the phenomenological quantities relevant to dark matter
experiments, such as the neutralino annihilation and elastic scattering cross
sections, and the underlying characteristics of the supersymmetric model, such
as the values of mu (and the composition of the lightest neutralino), m_A and
tan beta. We explore a broad range of supersymmetric models and then focus on a
smaller set of benchmark models. We find that by combining astrophysical
observations with collider measurements, mu can often be constrained far more
tightly than it can be from LHC data alone. In models in the A-funnel region of
parameter space, we find that dark matter experiments can potentially determine
m_A to roughly +/-100 GeV, even when heavy neutral MSSM Higgs bosons (A, H_1)
cannot be observed at the LHC. The information provided by astrophysical
experiments is often highly complementary to the information most easily
ascertained at colliders.Comment: 46 pages, 76 figure
Performance of the First ANTARES Detector Line
In this paper we report on the data recorded with the first Antares detector
line. The line was deployed on the 14th of February 2006 and was connected to
the readout two weeks later. Environmental data for one and a half years of
running are shown. Measurements of atmospheric muons from data taken from
selected runs during the first six months of operation are presented.
Performance figures in terms of time residuals and angular resolution are
given. Finally the angular distribution of atmospheric muons is presented and
from this the depth profile of the muon intensity is derived.Comment: 14 pages, 9 figure
Murchison Widefield Array limits on radio emission from Antares neutrino events
We present a search, using the Murchison Widefield Array (MWA), for electromagnetic (EM) counterparts to two candidate high-energy neutrino events detected by the ANTARES neutrino telescope in 2013 November and 2014 March. These events were selected by ANTARES because they are consistent, within 0°.4, with the locations of galaxies within 20 Mpc of Earth. Using MWA archival data at frequencies between 118 and 182 MHz, taken ~20 days prior to, at the same time as, and up to a year after the neutrino triggers, we look for transient or strongly variable radio sources that are consistent with the neutrino positions. No such counterparts are detected, and we set a 5s upper limit for low-frequency radio emission of ~1037 erg s-1 for progenitors at 20 Mpc. If the neutrino sources are instead not in nearby galaxies, but originate in binary neutron star coalescences, our limits place the progenitors at z 0.2. While it is possible, due to the high background from atmospheric neutrinos, that neither event is astrophysical, the MWA observations are nevertheless among the first to follow up neutrino candidates in the radio, and illustrate the promise of wide-field instruments like MWA for detecting EM counterparts to such events
A search for neutrino emission from the Fermi bubbles with the ANTARES telescope
Analysis of the Fermi-LAT data has revealed two extended structures above and below the Galactic Centre emitting gamma rays with a hard spectrum, the so-called Fermi bubbles. Hadronic models attempting to explain the origin of the Fermi bubbles predict the emission of high-energy neutrinos and gamma rays with similar fluxes. The ANTARES detector, a neutrino telescope located in the Mediterranean Sea, has a good visibility to the Fermi bubble regions. Using data collected from 2008 to 2011 no statistically significant excess of events is observed and therefore upper limits on the neutrino flux in TeV range from the Fermi bubbles are derived for various assumed energy cutoffs of the source
Search for magnetic monopoles with ten years of the ANTARES neutrino telescope
This work presents a new search for magnetic monopoles using data taken with the ANTARES neutrino telescope over a period of 10 years (January 2008 to December 2017). Compared to previous ANTARES searches, this analysis uses a run-by-run simulation strategy, with a larger exposure as well as a new simulation of magnetic monopoles taking into account the Kasama, Yang and Goldhaber model for their interaction cross-section with matter. No signal compatible with the passage of relativistic magnetic monopoles is observed, and upper limits on the flux of magnetic monopoles with β=v/c≥0.55, are presented. For ultra-relativistic magnetic monopoles the flux limit is ∼7×10−18 cm−2s−1sr−1
The positioning system of the ANTARES Neutrino Telescope
The ANTARES neutrino telescope, located 40km off the coast of Toulon in the Mediterranean Sea at a mooring depth of about 2475m, consists of twelve detection lines equipped typically with 25 storeys. Every storey carries three optical modules that detect Cherenkov light induced by charged secondary particles (typically muons) coming from neutrino interactions. As these lines are flexible structures fixed to the sea bed and held taut by a buoy, sea currents cause the lines to move and the storeys to rotate. The knowledge of the position of the optical modules with a precision better than 10cm is essential for a good reconstruction of particle tracks. In this paper the ANTARES positioning system is described. It consists of an acoustic positioning system, for distance triangulation, and a compass-tiltmeter system, for the measurement of the orientation and inclination of the storeys. Necessary corrections are discussed and the results of the detector alignment procedure are described
Performance of novel VUV-sensitive Silicon Photo-Multipliers for nEXO
Liquid xenon time projection chambers are promising detectors to search for
neutrinoless double beta decay (0), due to their response
uniformity, monolithic sensitive volume, scalability to large target masses,
and suitability for extremely low background operations. The nEXO collaboration
has designed a tonne-scale time projection chamber that aims to search for
0 of \ce{^{136}Xe} with projected half-life sensitivity of
~yr. To reach this sensitivity, the design goal for nEXO is
1\% energy resolution at the decay -value (~keV).
Reaching this resolution requires the efficient collection of both the
ionization and scintillation produced in the detector. The nEXO design employs
Silicon Photo-Multipliers (SiPMs) to detect the vacuum ultra-violet, 175 nm
scintillation light of liquid xenon. This paper reports on the characterization
of the newest vacuum ultra-violet sensitive Fondazione Bruno Kessler VUVHD3
SiPMs specifically designed for nEXO, as well as new measurements on new test
samples of previously characterised Hamamatsu VUV4 Multi Pixel Photon Counters
(MPPCs). Various SiPM and MPPC parameters, such as dark noise, gain, direct
crosstalk, correlated avalanches and photon detection efficiency were measured
as a function of the applied over voltage and wavelength at liquid xenon
temperature (163~K). The results from this study are used to provide updated
estimates of the achievable energy resolution at the decay -value for the
nEXO design
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