56 research outputs found
On the possibilities of large-scale radio and fiber optics detectors in cosmic rays
Different variants of radio and fiber optics detectors for registration of super high energy cascades in the atmosphere and in dense media are discussed. Particularly the possibilities for investigation of quasi horizontal cosmic ray showers (CRS) and simulated muons from these CRS with the help of radio detectors and fiber optics detectors located on the ice surface are considered
Implications of for high-energy observation
Absorption of high-energy over electrons above the W boson
production threshold is reexamined. It is pointed out that, in the case of
photon emissions along the direction of incident high-energy , the
kinematically allowed average energy carried by the final state hard photon can
be of the incident energy above the W boson production
threshold. The differential energy spectrum for the final state hard photon is
calculated. We also discuss implications of our results for the prospective
search of high-energy through this final state hard photon.Comment: 9 pages, 3 figures, RevTe
Experimental Limit on the Cosmic Diffuse Ultra-high Energy Neutrino Flux
We report results from 120 hours of livetime with the Goldstone Lunar
Ultra-high energy neutrino Experiment (GLUE). The experiment searches for <10
ns microwave pulses from the lunar regolith, appearing in coincidence at two
large radio telescopes separated by 22 km and linked by optical fiber. Such
pulses would arise from subsurface electromagnetic cascades induced by
interactions of >= 100 EeV neutrinos in the lunar regolith. No candidates are
yet seen, and the implied limits constrain several current models for
ultra-high energy neutrino fluxes.Comment: 4 pages, 4 figures, revtex4 style. New intro section, Fig. 2, Fig 4;
in final PRL revie
The TIANSHAN Radio Experiment for Neutrino Detection
An antenna array devoted to the autonomous radio-detection of high energy
cosmic rays is being deployed on the site of the 21 cm array radio telescope in
XinJiang, China. Thanks in particular to the very good electromagnetic
environment of this remote experimental site, self-triggering on extensive air
showers induced by cosmic rays has been achieved with a small scale prototype
of the foreseen antenna array. We give here a detailed description of the
detector and present the first detection of extensive air showers with this
prototype.Comment: 37 pages, 15 figures. Astroparticle Physics (in press
Characterization of neutrino signals with radiopulses in dense media through the LPM effect
We discuss the possibilities of detecting radio pulses from high energy
showers in ice, such as those produced by PeV and EeV neutrino interactions. It
is shown that the rich radiation pattern structure in the 100 MHz to few GHz
allows the separation of electromagnetic showers induced by photons or
electrons above 100 PeV from those induced by hadrons. This opens up the
possibility of measuring the energy fraction transmitted to the electron in a
charged current electron neutrino interaction with adequate sampling of the
angular distribution of the signal. The radio technique has the potential to
complement conventional high energy neutrino detectors with flavor information.Comment: 5 pages, 4 ps figures. Submitted to Phys. Rev. Let
Observation of the Askaryan Effect: Coherent Microwave Cherenkov Emission from Charge Asymmetry in High Energy Particle Cascades
We present the first direct experimental evidence for the charge excess in
high energy particle showers predicted nearly 40 years ago by Askaryan. We
directed bremsstrahlung photons from picosecond pulses of 28.5 GeV electrons at
the SLAC Final Focus Test Beam facility into a 3.5 ton silica sand target,
producing electromagnetic showers several meters long. A series of antennas
spanning 0.3 to 6 GHz were used to detect strong, sub-nanosecond radio
frequency pulses produced whenever a shower was present. The measured electric
field strengths are consistent with a completely coherent radiation process.
The pulses show 100% linear polarization, consistent with the expectations of
Cherenkov radiation. The field strength versus depth closely follows the
expected particle number density profile of the cascade, consistent with
emission from excess charge distributed along the shower. These measurements
therefore provide strong support for experiments designed to detect high energy
cosmic rays and neutrinos via coherent radio emission from their cascades.Comment: 10 pages, 4 figures. Submitted to Phys. Rev. Let
- âŠ