409 research outputs found
Behaviour of the EAS Age Parameter in the Knee Energy Region
Analyzing simulated EAS events generated with the CORSIKA code, the
characteristics of lateral distribution of electrons in EAS around the knee
energy region of the primary energy spectrum have been studied and compared
with experimental observations. The differences between the EGS4 and the NKG
output of CORSIKA in respect to electron radial density distribution have been
investigated. The relation between lateral and longitudinal age parameters has
been studied after introducing the notion of the local age parameter that
reflects the profile of the lateral distribution of electrons in EAS. The
present analysis motivates the inclusion of the lateral shower age in a
multiparameter study of EAS to extract information on hadronic interactions and
primary composition.Comment: Talk presented at XVI International Symposium on Very High Energy
Cosmic Ray Interactions (ISVHECRI 2010), Batavia, IL, USA (28 June - 2 July
2010). 4 pages, 5 figure
Comparing the energy spectra of ultra-high energy cosmic rays measured with EAS arrays
The energy spectra of ultra-high energy cosmic rays (CRs) measured with giant
extensive air shower (EAS) arrays exhibit discrepancies between the flux
intensities and/or estimated CR energies exceeding experimental errors. The
well-known intensity correction factor due to the dispersion of the measured
quantity in the presence of a rapidly falling energy spectrum is insufficient
to explain the divergence. Another source of systematic energy determination
error is proposed concerning the charged particle density measured with the
surface arrays, which arises due to simplifications (namely, the superposition
approximation) in nucleus-nucleus interaction description applied to the shower
modeling. Making use of the essential correction factors results in congruous
CR energy spectra within experimental errors. Residual differences in the
energy scales of giant arrays can be attributed to the actual overall accuracy
of the EAS detection technique used. CR acceleration and propagation model
simulations using the dip and ankle scenarios of the transition from galactic
to extragalactic CR components are in agreement with the combined energy
spectrum observed with EAS arrays.Comment: Accepted for publication in Ap
High energy hadrons in EAS at mountain altitude
An extensive simulation has been carried out to estimate the physical
interpretation of dynamical factors such as , in terms of high
energy interaction features, concentrated in the present analysis on the
average transverse momentum. It appears that the large enhancement observed for
versus primary energy, suggesting in earliest analysis a significant
rise of with energy, is only the result of the limited resolution of the
detectors and remains in agreement with a wide range of models used in
simulations.Comment: 13 pages, 6 PostScript figures, LaTeX Subm. to JPhys
Depth of maximum of extensive air showers and cosmic ray composition above 10**17 eV in the geometrical multichain model of nuclei interactions
The depth of maximum for extensive air showers measured by Fly's Eye and
Yakutsk experiments is analysed. The analysis depends on the hadronic
interaction model that determine cascade development. The novel feature found
in the cascading process for nucleus-nucleus collisions at high energies leads
to a fast increase of the inelasticity in heavy nuclei interactions without
changing the hadron-hadron interaction properties. This effects the development
of the extensive air showers initiated by heavy primaries. The detailed
calculations were performed using the recently developed geometrical multichain
model and the CORSIKA simulation code. The agreement with data on average depth
of shower maxima, the falling slope of the maxima distribution, and these
distribution widths are found for the very heavy cosmic ray mass spectrum
(slightly heavier than expected in the diffusion model at about 3*10**17 eV and
similar to the Fly's Eye composition at this energy).Comment: 11pp (9 eps figures
On the Possible Common Nature of Double Extensive Air Showers and Aligned Events
Double Extensive Air Showers and aligned events were discovered at energies E
{\gtsim} 1016 eV over fourth century back. But up to now there is no
sufficiently identical explanation of their nature. In this paper it is
expected that both types of events are the result of breakup of the string
formed in the collisions of super high energy particles
Diffractive Contribution to the Elasticity and the Nucleonic Flux in the Atmosphere
We calculate the average elasticity considering non-diffractive and single
diffractive interactions and perform an analysis of the cosmic-ray flux by
means of an analytical solution for the nucleonic diffusion equation. We show
that the diffractive contribution is important for the adequate description of
the nucleonic and hadronic fluxes in the atmosphere.Comment: 10 pages, latex, 2 figures (uuencoded PostScript
A New Method to Reconstruct the Energy and Determine the Composition of Cosmic Rays from the Measurement of Cherenkov Light and Particle Densities in Extended Air Showers
A Monte-Carlo study is presented using ground based measurements of the
electromagnetic part of showers initiated in the atmosphere by high energetic
cosmic rays to reconstruct energy and mass of primary particles with energies
above 300 TeV. With two detector arrays measuring Cherenkov light and particle
densities as realized in the HEGRA experiment shower properties are
reconstructed and interpreted to determine energy and energy per nucleon of the
primary particle.Comment: 16 pages, Latex, 8 eps figures, Lectures given at the XV Cracow
Summer School of Cosmology at Lodz, 199
Charm Production in DPMJET
In this work, charm production in the {\sc dpmjet} hadronic jet simulation is
compared to experimental data. Since the major application of {\sc dpmjet} is
the simulation of cosmic ray-induced air showers, the version of the code
integrated in the CORSIKA simulation package has been used for the comparison.
Wherever necessary, adjustments have been made to improve agreement between
simulation and data. With the availability of new muon/neutrino detectors that
combine a large fiducial volume with large amounts of shielding, investigation
of prompt muons and neutrinos from cosmic ray interactions will be feasible for
the first time. Furthermore, above TeV charmed particle decay
becomes the dominant background for diffuse extraterrestrial neutrino flux
searches. A reliable method to simulate charm production in high-energy
proton-nucleon interactions is therefore required.Comment: 10 pages, to be published in JCA
Hypermatrix factors for string and membrane junctions
The adjoint representations of the Lie algebras of the classical groups
SU(n), SO(n), and Sp(n) are, respectively, tensor, antisymmetric, and symmetric
products of two vector spaces, and hence are matrix representations. We
consider the analogous products of three vector spaces and study when they
appear as summands in Lie algebra decompositions. The Z3-grading of the
exceptional Lie algebras provide such summands and provides representations of
classical groups on hypermatrices. The main natural application is a formal
study of three-junctions of strings and membranes. Generalizations are also
considered.Comment: 25 pages, 4 figures, presentation improved, minor correction
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