527 research outputs found
Searching for high-energy neutrinos in coincidence with gravitational waves with the ANTARES and VIRGO/LIGO detectors
Cataclysmic cosmic events can be plausible sources of both gravitational
waves (GW) and high-energy neutrinos (HEN). Both GW and HEN are alternative
cosmic messengers that may escape very dense media and travel unaffected over
cosmological distances, carrying information from the innermost regions of the
astrophysical engines. For the same reasons, such messengers could also reveal
new, hidden sources that were not observed by conventional photon astronomy.
Requiring the consistency between GW and HEN detection channels shall enable
new searches as one has significant additional information about the common
source. A neutrino telescope such as ANTARES can determine accurately the time
and direction of high energy neutrino events, while a network of gravitational
wave detectors such as LIGO and VIRGO can also provide timing/directional
information for gravitational wave bursts. By combining the information from
these totally independent detectors, one can search for cosmic events that may
arrive from common astrophysical sources.Comment: 4 pages, 2 figures. Prepared for the Proceedings of the 31st ICRC,
Lodz (Poland), July 7-15, 200
Detection of inclined and horizontal showers in the Pierre Auger Observatory
The Pierre Auger Observatory can detect with high efficiency the air showers
induced by ultra-high energy cosmic rays incident at large (> 60 deg.) zenith
angles. We describe here the specific characteristics of inclined and
horizontal showers, as well as the characteristics of their signal in the
surface detector. We point out their relevance both to extend the potential of
the detector, and in the context of the detection of high-energy cosmic
neutrinos.Comment: 3 pages, 2 figures. To be published in the Proceedings of the
CINVESTAV Advanced Summer School, 2005 (Mexico
KM3NeT: A km^3-scale neutrino telescope in the Mediterranean Sea
International audienceNot Availabl
Multi-messenger programs in ANTARES: Status and prospects
With an instrumented volume of about 0.015 km3, ANTARES is currently the largest neutrino telescope operating in the Northern Hemisphere. One of its main goals is the detection of high-energy neutrinos from (extra-)galactic astrophysical sources. Such observations would provide important clues about the processes at work in those sources, and possibly help solve the puzzle of ultra-high energy cosmic rays. In this context, ANTARES is developing several on- and off-line programs to improve its capabilities of revealing possible correlations (in space and time) of neutrinos with other cosmic messengers: photons (in different ranges of wavelengths), cosmic rays and gravitational waves
Recent results from the ANTARES neutrino telescope
8 pages, 9 figures. Prepared for the Proceedings of RICAP-13 Roma International Conference on Astroparticle Physics (Rome, 22-24 May 2013)International audienceThe ANTARES neutrino telescope is currently the largest operating water Cherenkov detector and the largest neutrino detector in the Northern Hemisphere. Its main scientific target is the detection of high-energy (TeV and beyond) neutrinos from cosmic accelerators, as predicted by hadronic interaction models, and the measurement of the diffuse neutrino flux. Its location allows for surveying a large part of the Galactic Plane, including the Galactic Centre. In addition to the standalone searches for point-like and diffuse high-energy neutrino signals, ANTARES has developed a range of multi-messenger strategies to exploit the close connection between neutrinos and other cosmic messengers such as gamma-rays, charged cosmic rays and gravitational waves. This contribution provides an overview of the recently conducted analyses, including a search for neutrinos from the Fermi bubbles region, searches for optical counterparts with the TAToO program, and searches for neutrinos in correlation with gamma-ray bursts, blazars, and microquasars. Further topics of investigation, covering e.g. the search for neutrinos from dark matter annihilation, searches for exotic particles and the measurement of neutrino oscillations, are also reviewed
UHE neutrino damping in a thermal gas of relic neutrinos
We present a calculation of the damping of an ultra-energetic (UHE) cosmic
neutrino travelling through the thermal gas of relic neutrinos, using the
formalism of finite-temperature field theory. From the self-energy diagram due
to Z exchange, we obtain the annihilation cross section for an UHE neutrino
interacting with an antineutrino from the background. This method allows us to
derive the full expressions for the UHE neutrino transmission probability,
taking into account the momentum of relic neutrinos. We compare our results
with the approximations in use in the literature. We discuss the effect of
thermal motion on the shape of the absorption dips for different UHE neutrino
fluxes as well as in the context of relic neutrino clustering. We find that for
ratios of the neutrino mass to the relic background temperature or
smaller, the thermal broadening of the absorption lines could significantly
affect the determination of the neutrino mass and of the characteristics of the
population of UHE sources.Comment: 18 pages, 6 figures. Typos corrected. More accurate treatment of the
interaction with relic neutrino clusters. Accepted for publication in
Astroparticle Physic
Thermal effects on the absorption of ultra-high energy neutrinos by the cosmic neutrino background
We use the formalism of finite-temperature field theory to study the
interactions of ultra-high energy (UHE) cosmic neutrinos with the background of
relic neutrinos and to derive general expressions for the UHE neutrino
transmission probability. This approach allows us to take into account the
thermal effects introduced by the momentum distribution of the relic neutrinos.
We compare our results with the approximate expressions existing in the
literature and discuss the influence of thermal effects on the absorption dips
in the context of favoured neutrino mass schemes, as well as in the case of
clustered relic neutrinos.Comment: 3 pages, 2 figures. Prepared for the Proceedings of the 9th
International Conference on Topics in Astroparticle and Underground Physics
(TAUP 2005), Zaragoza (Spain), September 10-14, 200
Insights on neutrino lensing
We discuss the gravitational lensing of neutrinos by astrophysical objects.
Unlike photons, neutrinos can cross a stellar core; as a result, the lens
quality improves. We also estimate the depletion of the neutrino flux after
crossing a massive object and the signal amplification expected. While Uranians
alone would benefit from this effect in the Sun, similar effects could be
considered for binary systems.Comment: 15 pages, 4 figures, to be published in Phys. Lett.
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