1,216 research outputs found
Muons and neutrinos
The first generation of large and precise detectors, some initially dedicated to search for nucleon decay has accumulated significant statistics on neutrinos and high-energy muons. A second generation of even better and bigger detectors are already in operation or in advanced construction stage. The present set of experimental data on muon groups and neutrinos is qualitatively better than several years ago and the expectations for the following years are high. Composition studies with underground muon groups, neutrino detection, and expected extraterrestrial neutrino fluxes are discussed
Gamma Ray Astronomy with Underground Detectors
Underground detectors measure the directions of up-coming muons of neutrino
origin. They can also observe down-going muons made by gamma rays in the
Earth's atmosphere. Although gamma ray showers are muon-poor, they produce a
sufficient number of muons to detect the sources observed by GeV and TeV
telescopes. With a threshold higher by one hundred and a probability of muon
production of about for the shallower AMANDA and Lake Baikal detectors,
these instruments can, for a typical GRO source, match the detection efficiency
of a GeV satellite detector since their effective area is larger by a factor
. The muons must have enough energy for accurate reconstruction of their
direction. Very energetic muons on the other hand are rare because they are
only produced by higher energy gamma rays whose flux is suppressed by the
decreasing flux at the source and by absorption on interstellar light. We show
that there is a window of opportunity for muon astronomy in the 100~GeV energy
region which nicely matches the threshold energies of the AMANDA and Lake
Baikal detectors.Comment: Standard Latex, 8 pages, no figures. Compressed postscript version at
http://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-901.ps.Z or at
ftp://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-901.ps.
Neutrino astronomy and the atmospheric background
Some aspects of neutrino astronomy are illustrated by calculating the neutrino-induced muon flux from Cygnus X-3 binary X-ray source. The signal depends primarily on the power in cosmic rays at the source and on the distance to the source, and only relatively little on details of the matter distribution in the neighborhood of the source
Atmospheric neutrinos observed in underground detectors
Atmospheric neutrinos are produced when the primary cosmic ray beam hits the atmosphere and initiates atmospheric cascades. Secondary mesons decay and give rise to neutrinos. The neutrino production was calculated and compared with the neutrino fluxes detected in underground detectors. Contained neutrino events are characterized by observation of an interaction within the fiducial volume of the detector when the incoming particle is not observed. Both the neutrino flux and the containment requirement restrict the energy of the neutrinos observed in contained interactions to less than several GeV. Neutrinos interact with the rock surrounding the detector but only muon neutrino interactions can be observed, as the electron energy is dissipated too fast in the rock. The direction of the neutrino is preserved in the interaction and at energies above 1 TeV the angular resolution is restricted by the scattering of the muon in the rock. The muon rate reflects the neutrino spectrum above some threshold energy, determined by the detector efficiency for muons
Cosmic ray albedo gamma rays from the quiet sun
We estimate the flux of gamma-rays that result from collisions of high energy galactic cosmic rays with the solar atmosphere. An important aspect of our model is the propagation of cosmic rays through the magnetic fields of the inner solar systems. We use diffusion to model propagation down to the bottom of the corona. Below the corona we trace particle orbits through the photospheric fields to determine the location of cosmic ray interactions in the solar atmosphere and evolve the resultant cascades. For our nominal choice of parameters, we predict an integrated flux of gamma rays (at 1 AU) of F(E(sub gamma) greater than 100 MeV) approximately = 5 x 10(exp -8)/sq cm sec. This can be an order of magnitude above the galactic background and should be observable by the Energetic Gamma Ray experiment telescope (EGRET)
Study of the Correlations Between the Highest Energy Cosmic Ray Showers and Gamma Ray Bursts
We examine the correlation between the arrival direction of ultra high energy
cosmic ray showers and gamma ray bursts in the third BATSE catalog. We find no
correlation between the two data sets. We also find no correlations between a
pre-BATSE burst catalog and the Haverah Park Ultra High Energy shower set that
cover approximately the same period of time.Comment: 1 uuencoded g-zipped postscript file containing text and figure
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