48 research outputs found
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
Simulation of the cosmic ray tau neutrino telescope (CRTNT) experiment
A tau lepton can be produced in a charged current interaction by cosmic ray
tau neutrino with material inside a mountain. If it escapes from the mountain,
it will decay and initiate a shower in the air, which can be detected by an air
shower fluorescence/Cherenkov light detector. Designed according to such a
principle, the Cosmic Ray Tau Neutrino Telescope (CRTNT) experiment, located at
the foothill of Mt. Balikun in Xinjiang, China, will search for very
high-energy cosmic tau neutrinos from energetic astrophysical sources by
detecting those showers. This paper describes a Monte Carlo simulation for a
detection of tau neutrino events by the CRTNT experiment. Ultra-high-energy
cosmic ray events are also simulated to estimate the potential contamination.
With the CRTNT experiment composed of four detector stations, each covering 64
by 14 degrees field of view, the expected event rates are 28.6, 21.9 and 4.7
per year assuming AGN neutrino flux according to Semikoz et. al. 2004, MPR AGN
jet model and SDSS AGN core model, respectively. Null detection of such tau
event by the CRTNT experiment in one year could set 90% C.L. upper limit at
19.9 (eV^-1 cm^-2 s^-1 sr^-1) for E^-2 neutrino spectrum.Comment: 14 page
Test of Hadronic Interaction Models in the Forward Region with KASCADE Event Rates
An analysis of muon and hadron rates observed in the central detector of the
KASCADE experiment has been carried out. The data are compared to CORSIKA
simulations employing the high-energy hadronic interaction models QGSJET,
DPMJET, HDPM, SIBYLL, and VENUS. In addition, first results with the new
hadronic interaction model neXus 2 are discussed. Differences of the model
predictions, both among each other and when confronted with measurements, are
observed. The hadron rates mainly depend on the inelastic cross-section and on
the contribution of diffraction dissociation. The discrepancy between
simulations and measurements at low primary energies around 5 TeV can be
reduced by increasing the non-diffractive part of the inelastic cross-section
of nucleon-air interactions. Examination of hadron multiplicities points
towards harder spectra of secondary pions and kaons needed in the calculations.Comment: 14 pages, 7 figures, corresponding author: M. Risse, accepted for
publication in J. Phys. G: Nucl. Part. Phy
All-particle primary energy spectrum in the 3-200 PeV energy range
We present all-particle primary cosmic-ray energy spectrum in the 3-200 PeV
energy range obtained by a multi-parametric event-by-event evaluation of the
primary energy. The results are obtained on the basis of an expanded EAS data
set detected at mountain level (700 g/cm^2) by the GAMMA experiment. The energy
evaluation method has been developed using the EAS simulation with the SIBYLL
interaction model taking into account the response of GAMMA detectors and
reconstruction uncertainties of EAS parameters. Nearly unbiased (<5%) energy
estimations regardless of a primary nuclear mass with an accuracy of about
15-10% in the 3-200 PeV energy range respectively are attained. An irregularity
('bump') in the spectrum is observed at primary energies of ~74 PeV. This bump
exceeds a smooth power-law fit to the data by about 4 standard deviations. Not
rejecting stochastic nature of the bump completely, we examined the systematic
uncertainties of our methods and conclude that they cannot be responsible for
the observed feature.Comment: Accepted by J.Phys.G: Nucl.Part.Phy
Anisotropy studies around the galactic centre at EeV energies with the Auger Observatory
Data from the Pierre Auger Observatory are analyzed to search for
anisotropies near the direction of the Galactic Centre at EeV energies. The
exposure of the surface array in this part of the sky is already significantly
larger than that of the fore-runner experiments. Our results do not support
previous findings of localized excesses in the AGASA and SUGAR data. We set an
upper bound on a point-like flux of cosmic rays arriving from the Galactic
Centre which excludes several scenarios predicting sources of EeV neutrons from
Sagittarius . Also the events detected simultaneously by the surface and
fluorescence detectors (the `hybrid' data set), which have better pointing
accuracy but are less numerous than those of the surface array alone, do not
show any significant localized excess from this direction.Comment: Matches published versio
An upper limit to the photon fraction in cosmic rays above 10^19 eV from the Pierre Auger Observatory
An upper limit of 16% (at 95% c.l.) is derived for the photon fraction in cosmic rays with energies above 10^19 eV, based on observations of the depth of shower maximum performed with the hybrid detector of the Pierre Auger Observatory. This is the first such limit on photons obtained by observing the fluorescence light profile of air showers. This upper limit confirms and improves on previous results from the Haverah Park and AGASA surface arrays. Additional data recorded with the Auger surface detectors for a subset of the event sample, support the conclusion that a photon origin of the observed events is not favoured
CORSIKA: A Monte Carlo Code to Simulate Extensive Air Showers
This study concerns the evolution of the information seeking and use models for professionals essentially, the information access practices. Coming from Anglo-Saxon literature, this new information science research trend, evolve with paradigms and different information seeking and use models have emerged, in order to explain how professional seeks information and what can be done in order to help them. Two main categories can be distinguished : the information seeking and use model versus the information retrieval model. So we will present today this diversity of models and we will evaluate them in order to see if a convergence is possible with the same vocabulary and procedures
Long-lived Staus From Cosmic Rays.
The collision of a high energy cosmic ray with a nucleon in the upper
atmosphere could produce long-lived heavy particles. Such particles would be
very penetrating, since the energy loss in matter scales as the inverse mass,
and could reach a neutrino telescope like IceCube from large zenith angles.
Here we study this possibility and focus on the long-lived stau of SUSY models
with a gravitino LSP. The signal would be a pair of muon-like parallel tracks
separated by 50 meters along the detector. We evaluate the background of muon
pairs and show that any events from zenith angles above 80 degrees could be
explained by the production of these heavy particles by cosmic rays.Comment: 6 pages, 6 figure