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1.
《Comptes Rendus Physique》2004,5(4):495-503
The nature of the primary particle giving rise to an atmospheric shower may be, to some extent, inferred from the observable properties: longitudinal profile (especially position of the maximum of the number of charged particles) or shape at ground level (lateral distribution, curvature and thickness of the shower front, muonic component). Distinguishing different nuclei cannot be performed unambiguously on a single shower, because of the random fluctuations in the first steps of the cascade; however, it is possible to study the composition of the incident flux on a statistical basis: showers from heavier nuclei have a faster development, and contain more muons. The uncertainties on the hadronic interactions at the highest energies limit the reliability of the identification. Other primaries, if they exist, could be easier to distinguish. Photons would give a slower development than protons, especially at highest energies, and a very reduced muonic component; neutrinos would be characterized by deep interactions in the atmosphere, or even within the Earth, giving almost horizontal showers with a large electromagnetic component, clearly different from the muonic tail of showers induced in the upper atmosphere by nuclei. Such ‘exotic’ primaries have not yet been observed. To cite this article: P. Billoir, P. Sommers, C. R. Physique 5 (2004). 相似文献
2.
A new method has been proposed for estimating the energy of inclined extensive air showers from signals of ground-based scintillation detectors of the Yakutsk extensive air shower array that are located at a distance of 600 m from the shower axis in the plane of the array and from the calculations of these signals within two hadron interaction models. New estimates of the energy have been obtained for 116 showers detected in different years. It has been shown that the energy spectra of particles of primary cosmic radiation measured at the Yakutsk array are in agreement with world data. 相似文献
3.
V. I. Yakovlev 《Bulletin of the Lebedev Physics Institute》2013,40(1):17-20
Double extensive air showers were studied at the Tien Shan high-mountain scientific station of the Lebedev Physical Institute using two different installations. One measured the electron-photon shower component, the other measured Cherenkov radiation. Double showers separated by a time interval of ~100 ns were detected by both setups. The frequency of the occurrence of such showers in each setup is analyzed. It is shown that these frequencies are identical when observing vertical showers (the zenith angle ? < 60°). 相似文献
4.
In this article, we study the interactions of stable, hadronising new states, arising in certain extensions of the standard model. A simple model, originally intended for stable gluino hadrons, is developed to describe the nuclear interactions of hadrons containing any new colour triplet or octet stable parton. Hadron mass spectra, nuclear scattering cross sections and interaction processes are discussed. Furthermore, an implementation of the interactions of heavy hadrons in GEANT 3 is presented, signatures are studied, and a few remarks about possible detection with the ATLAS experiment are given.Received: 2 April 2004, Published online: 6 August 2004 相似文献
5.
Over a period of more than 30 years, the knee in the spectrum of extensive air showers (EAS) generated by cosmic radiation has been explained in two ways: as a consequence of a cusp in the energy spectrum of primary cosmic rays or as a consequence of a change undergone by the process of multiparticle hadron production in the interactions of primary protons with nuclei of air atoms. Investigations at the Tien Shan EAS array confirm a change in the properties of showers generated by protons near the upper boundary of the atmosphere and evince the invariability of the energy spectrum of protons in the energy range 103–105 TeV. 相似文献
6.
We consider the scattering of brane fields due to t-channel massive graviton exchanges in the Randall-Sundrum model. The eikonal amplitude is analytically calculated and both differential and total neutrino-nucleon cross sections are estimated. The event rate of quasi-horizontal air showers induced by cosmic neutrinos, which can be detected at the Pierre Auger Observatory, is presented for two different fluxes of cosmogenic neutrinos.Received: 27 December 2004, Published online: 8 June 2005 相似文献
7.
8.
A. A. Ivanov 《JETP Letters》2010,91(5):209-214
The analysis of the systematic errors in the determination of the energy of the particles of primary cosmic radiation that
are inherent in the method for measuring extensive air showers (EASs) indicates the necessity of the exact inclusion of fragmentation
in the nuclear interactions. The application of such a model developed for describing the experiments at the Relativistic
Heavy Ion Collider improves the agreement between the energy spectra of the ultrahigh-energy cosmic rays measured at giant
EAS arrays. It has been shown that the difference between the measured primary cosmic radiation flux intensities and the energies
of the primary particles is within the methodical and instrumental errors. The real accuracy of the EAS method of studying
ultrahigh-energy cosmic rays has been estimated using the data from six arrays. 相似文献
9.
Luis Anchordoqui María Teresa Dova Thomas McCauley Stephen Reucroft 《Annals of Physics》2004,314(1):145-207
The properties of cosmic rays with energies above 106 GeV have to be deduced from the spacetime structure and particle content of the air showers which they initiate. In this review we summarize the phenomenology of these giant air showers. We describe the hadronic interaction models used to extrapolate results from collider data to ultra high energies, and discuss the prospects for insights into forward physics at the LHC. We also describe the main electromagnetic processes that govern the longitudinal shower evolution, as well as the lateral spread of particles. Armed with these two principal shower ingredients and motivation from the underlying physics, we provide an overview of some of the different methods proposed to distinguish primary species. The properties of neutrino interactions and the potential of forthcoming experiments to isolate deeply penetrating showers from baryonic cascades are also discussed. We finally venture into a terra incognita endowed with TeV-scale gravity and explore anomalous neutrino-induced showers. 相似文献
10.
11.
O. E. Badawy M. El-Nadi S. A. El-Sharkawy M. K. Hegab M. M. Sherif 《Zeitschrift für Physik A Hadrons and Nuclei》1983,311(1-2):105-112
An analysis for 2,000 events produced by 2.1 GeV/c/n alpha particles in nuclear emulsion has been carried out. Multiplicity and angular distributions of charged secondaries have been measured and correlation among them are discussed. The presented data are compared with relevant values from proton and14N interactions with nuclei. The multiplicity distribution of showers has been tested by a modified independent nucleon-nucleus multiple scattering model (INAM) of reference [8], and by the model of reference [12]. 相似文献
12.
A. Misaki 《Il Nuovo Cimento C》1990,13(4):733-760
Summary High-energy neutrinos produce finally high-energy electromagnetic cascade showers. For the detectio of high-energy neutrinos,
it is necessary to examine the behaviour of the electromagnetic cascade showers in the higher-energy region. It is well known
that the LPM effect plays a decisive role in the electromagnetic cascade shower development at higher energies. In the present
paper, the behaviour of electromagnetic cascade showers including the LPM effect (LPM showers) in standard rock is examined
using the calculational technique developed by Fujimaki and Misaki. In order to clarify the characteristics of LPM showers,
similar calculations are also carried out for cascade showers in the absence of the LPM effect (BH showers). Comparisons between
the two different kinds of cascade showers are made over electron transition curves, track lengths and fractional dissipated
energies. Finally, the strong deviation of LPM showers from the normal BH showers is emphasized. 相似文献
13.
R. U. Beisembaev Yu. N. Vavilov M. I. Vil’danova N. G. Vil’danov V. V. Zhukov A. V. Kruglov R. A. Nam V. P. Pavlyuchenko V. A. Ryabov A. V. Stepanov Zh. S. Takibaev V. I. Yakovlev 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(3):354-356
Extensive air showers (EASes) at zenith angles of 70–80 degrees with Vavilov-Cherenkov radiation having two and three maxima were registered at the Tian Shan Mountain Station of the Lebedev Physical Institute. In each such event, the subsequent maxima came with a time delay of 100 or more nanoseconds. Extensive air showers at a zenith angle of 70° with charged particles and Vavilov-Cherenkov radiation were also registered. 相似文献
14.
Nanophotonics, defined as nanoscale optical science and technology, is a new multidisciplinary frontier. This article presents
our studies on nanoscale matter–radiation interactions utilizing nanoscale confinement of radiation as well as on nanoscale
photochemical transformations, particularly nanoscale nonlinear optical interactions. The selected examples of our studies
include nanoscopic optical harmonic generation, multiphoton fluorescence, transient absorption dynamics, surface-plasmon-enhanced
two-photon fluorescence, and nonlinear optical information storage.
Received: 12 December 2001 / Published online: 11 June 2002 相似文献
16.
Hansen HD Uggerhøj UI Biino C Ballestrero S Mangiarotti A Sona P Ketel TJ Vilakazi ZZ 《Physical review letters》2003,91(1):014801
Experimental results for the radiative energy loss of 149, 207, and 287 GeV electrons in a thin Ir target are presented. From the data we conclude that at high energies the radiation length increases in accordance with the Landau-Pomeranchuk-Migdal (LPM) theory and thus electrons become more penetrating the higher the energy. The increase of the radiation length as a result of the LPM effect has a significant impact on the behavior of high-energy electromagnetic showers. 相似文献
17.
A macroscopic model of radio emission from extensive air showers is developed. This model is appropriate for calculating this
radio emission at frequencies below 100 MHz. It is constructed on the basis of an analysis of the radiation integral and is
verified by comparing field observables predicted by the model with the respective results obtained within the microscopic
approach to calculating radio emission from extensive air showers. 相似文献
18.
It has been found that unknown meteor showers could be efficiently discovered from the single station video meteor database
of the International Meteor Organization (IMO) by assuming the geocentric velocity and adjusting it within the dynamically
permitted range. The mean geocentric velocities of new meteor showers can be obtained, as well as the coordinates of the radiants.
The activity period and maximum time can also be obtained if there are sufficient shower meteors. All single station video
meteor observations between February 13 and 17 (from 2000 to 2005) in IMO’s database are processed with this method. As a
result, two new meteor showers, one near RA=245.10°, Dec=41.82° in Hercules and the other near RA=233.03°, Dec=17.04° in Serpenids,
are discovered. Some dynamical characteristics of the new meteor showers are also determined. Considering the random nature
on the selection of period in this work, it is expected that there are some more potential new meteor showers in IMO’s video
database.
Supported by the National Natural Science Foundation of China (Grant No. 10373004) 相似文献
19.
《X射线光谱测定》2004,33(5):360-371
Systematic investigations of the width dependence on the x‐ray beam propagation mechanism for a narrow extended slit formed by two plane dielectric plates are presented. It is shown that the mechanism of a multiple consecutive total reflection for Cu Kα radiation dominates in a slit width range s ≥ 3 µm. At the same time the manner of Cu Kα radiation propagation for super‐narrow slits s ≤ 0.1 µm is very different from the multiple total reflection mechanism. The x‐ray beam intensity proves to be constant for all this range of magnitude. This gives grounds to expect that the super‐narrow slit area is characterized by a specific type of mechanism of x‐ray beam propagation: waveguide‐resonance. A simple model for the waveguide‐resonance propagation mechanism based on the formation of a uniform x‐ray standing wave interference field in the total space of a narrow extended slit was developed. The design of a new x‐ray optical device, namely a planar x‐ray waveguide‐resonator, is proposed based on the waveguide‐resonance mechanism. Some properties of the composite planar x‐ray waveguide‐resonator are discussed. It is shown that under specific conditions the composite waveguide can demonstrate a partial tunneling effect of the x‐ray beam. The main applications of the new technique are discussed. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献