High Energy Cosmic Ray Interactions Research Articles

Inclined Air Showers and Neutrino Detection

The role of inclined showers is reviewed paying some attention to the subject from a historical perspective and how it lead to two different developments, the study of inclined showers due to high energy cosmic ray interactions and the search for high energy neutrinos. The interest of detecting showers of zenith angles above 60° with arrays of particle detectors is discussed pointing out how it complements standard cosmic ray measurements with showers of zeniths below 60° as well as the fluorescence technique. The main characteristics of the search for τ neutrinos interacting in the Earth's crust nearly horizontally are discussed and contrasted to the search of neutrino interactions in the atmosphere.

Uncertanties of atmospheric high-energy muon fluxes and spectrum of primary cosmic rays

New results of calculations of nucleon, π-and K-meson, and muon fluxes generated during high energy cosmic ray interactions with the Earth’s atmosphere are presented. The calculations are based on the method of solving the nuclear cascade equations with allowance for non-scaling behavior of inclusive hadron production cross sections, increase of cross sections of inelastic hadron-nucleus collisions with energy, and non-power-law character of primary spectrum. The hadron and muon fluxes are calculated at different atmospheric altitude levels for several spectral models and compositions of primary cosmic rays. Results of calculations are compared with recent measurements using the L3+Cosmic and CosmoALEPH facilities.

High Energy Cosmic Ray Interactions - an Overview

The status of present theoretical description of very high energy hadronic interactions is reviewed. The impact of new results of accelerator and cosmic ray experiments on hadronic interaction model constructions is discussed in detail. Special attention is payed to remaining uncertainties in model extrapolations into the ultra-high energy domain, in particular, concerning model predictions for the muon component of extensive air showers. New promising theoretical approaches are outlined and future experimental prospects are discussed.

Very High Energy Cosmic Rays and Their Interactions

The investigation of high energy cosmic rays and their interactions is a very active field of research. This article summarizes the progress made during the last years as reflected by the contributions to the XIII International Symposium on Very High Energy Cosmic Ray Interactions held in Pylos, Greece.

Interactions of high-energy cosmic rays with extragalactic infrared radiation background

We consider the modification of extragalactic cosmic ray spectrum caused by cosmic ray interactions with infrared background photons which are present in the extragalactic space together with relic photons. It is assumed that cosmic ray spectrum at superhigh energies has extragalactic origin and is proton dominated.

Coplanar emission in very high energy cosmic ray interactions

The alignment of very high energy secondary cosmic rays, implying coplanar emissions, was observed at both stratospheric and mountain altitudes by several x-ray emulsion chamber experiments. This paper investigates the physical relevance of the experimental observations through detailed Monte Carlo calculations carried out with the CORSIKA program combining different models of high energy hadronic interaction. The physical factors likely to induce or to influence this phenomenon are discussed.

On sensitivity of Cherenkov radiation to the dynamics of high-energy cosmic ray interactions

A simulation study of the effects resulting from creation of quark–gluon plasma in high-energy collisions of cosmic iron nuclei with the air has been carried out. The Cherenkov light emission has been found to reveal some features of the dynamics of high-energy hadronic interactions.

Low-cost data acquisition card for school-network cosmic ray detectors

The Cosmic Ray Observatory Project (CROP) at University of Nebraska/Lincoln and the Washington Area Large-scale Time coincidence Array (WALTA) at University of Washington/Seattle are among several outreach projects siting cosmic-ray detectors at local high schools in cities around North America, to study the origins and interactions of high-energy cosmic rays. In a collaboration between QuarkNet, the outreach program based at Fermilab, CROP, and WALTA, a low-cost data acquisition electronics card has been developed to collect and synchronize the data from each detector site. The cost for each card is under US$500 for parts, functionally replacing much more expensive electronics crates and modules at each high school site. The card has 4 analog discriminator inputs for photo-multiplier tube signals, a 4-channel Time-to-Digital converter for local coincidence and time-over-threshold measurements at 0.75 ns resolution, programmable trigger logic via a CPLD and microcontroller, and a built-in low-cost GPS receiver/antenna module (via external cable) to provide event trigger time stamps at better than 100 ns accuracy. Temperature sensors and a barometer are also integrated to record environmental data along with the counter data. The card connects to any PC or laptop via a standard RS-232 serial port for data output and control. The microcontroller and CPLD are field programmable and therefore make the card functionality flexible and easy to upgrade.

Comparison of high-energy galactic and atmospheric tau neutrino flux

We compare the tau neutrino flux arising from the galaxy and the earth atmosphere for 10 3⩽ E/GeV⩽10 11. The intrinsic and oscillated tau neutrino fluxes from both sources are calculated. The intrinsic galactic ν τ flux ( E⩾10 3 GeV) is calculated by considering the interactions of high-energy cosmic-rays with the matter present in our galaxy, whereas the oscillated galactic ν τ flux is coming from the oscillation of the galactic ν μ flux. For the intrinsic atmospheric ν τ flux, we extend the validity of a previous calculation from E⩽10 6 GeV up to E⩽10 11 GeV. The oscillated atmospheric ν τ flux is, on the other hand, rather suppressed. We find that, for 10 3⩽ E/GeV⩽5×10 7, the oscillated ν τ flux along the galactic plane dominates over the maximal intrinsic atmospheric ν τ flux, i.e., the flux along the horizontal direction. We also briefly mention the presently envisaged prospects for observing these high-energy tau neutrinos.

Study of high energy cosmic ray interactions at chacaltaya laboratory

Cosmic rays physics is currently studied with rather sophisticated detectors operating in a variety of either experimental conditions or atmospheric depths in the world. In this paper we present the main properties of the observed features of high-energy nuclear interaction phenomena of cosmic rays, with particular emphasis on some experimental observations made by the emulsion chamber technique at Chacaltaya Laboratory (Bolivia, 5230 m a.s.l.). A discussion on the past and present achievements as well as the future prospects of high altitude mountain laboratories for cosmic ray physics is presented.

Study of muon bundles observed by the MACRO underground experiment

The MACRO underground experiment performed a systematic experimental study of muon bundle structure. The aim is to gain a better understanding of the features of the high energy cosmic ray interactions. We present here the analyses of the muon lateral distribution (decoherence function) based on two different methods (detector dependent and detector independent method); moreover, the reliability of the hadronic interaction model in reproducing the shower development features at the highest energy can be studied selecting high multiplicity muon bundles; the analysis of the separation between muon pairs of this subsample is discussed.

High-energy cosmic-ray interactions

The problems under review include unusual results observed in cosmic-ray investigations which were not explained and are now up-to-date.

Observations of cosmic gamma ray bursts with WATCH on EURECA

19 Cosmic Gamma-Ray Bursts were detected by the WATCH wide field X-ray monitor during the 11 months flight of EURECA. The identification of the bursts were complicated by a high frequency of background of events caused by high energy cosmic ray interactions in the detector and by low energy, trapped particle streams. These background events may simulate the count rate increases characteristic of cosmic gamma bursts. For 12 of the detected events, their true cosmic nature have been confirmed through consistent localizations of the burst sources based on several independent WATCH data sets. The derived positions of the bursts are reported. Additionally, most of the events have been confirmed by coincident detections with instruments on other spacecrafts. The features of two of the bursts and the results of searches for related events in the optical are described.

Observation of attenuation behaviour of hadrons in extremely high energy cosmic ray interactions: New hadronic state?

Experimental results are presented on high energy cosmic-ray hadron interactions recorded in homogeneous-type thick lead chambers (total thickness being 60 cm and 110 cm) exposed at the Pamirs (atmospheric depth 595 g/ cm 2). High energy cosmic-ray hadron flux is measured. The attenuation mean free path of the arriving cosmic-ray hadrons of E h γ ≥ 6 TeV measured in the chamber is obtained as 252 ± 30 g/cm 2 of lead. However, for the high energy hadrons ( E( γ) ≥ 10 TeV) constituting cosmic-ray families of the highest energy range, ΣE( γ) ≥ 700 TeV, which have been accumulated so far in the series exposures at the Pamirs and analysed by MSU group, the attenuation mean free path of hadrons in lead has turned out to be as short as 170 −26 +47 g/cm 2 with 95% CL by the maximum likelihood method. The present experimental result of such a short attenuation length of hadrons in cosmic-ray families is essentially consistent with that obtained for high energy hadrons ( E( γ) ≥ 10 TeV) constituting the “Chiron-type” families of ΣE( γ)>100 TeV in the Chacaltaya two-storeyed chamber experiments. The anomalous transition characteristics of high energy hadrons in lead is found and examples are presented. The physical significance of the experimental results on extremely high energy hadron interactions is discussed.

A summary of the VII snternational symposium on very high energy cosmic ray interactions

A summary of the VII snternational symposium on very high energy cosmic ray interactions

A FULL-ACCEPTANCE DETECTOR FOR SSC PHYSICS AT LOW AND INTERMEDIATE MASS SCALES: AN EXPRESSION OF INTEREST TO THE SSC

A FULL-ACCEPTANCE DETECTOR FOR SSC PHYSICS AT LOW AND INTERMEDIATE MASS SCALES: AN EXPRESSION OF INTEREST TO THE SSC

Signals of "new physics" in high-energy cosmic-ray interactions.

In some composite models of quarks and leptons, leptons are expected to develop strong interactions at high energies. This hypothesis can be tested by studying the absorption of high-energy particles emitted by point sources in the sky on the cosmic microwave background. Data on Cygnus X-3 exhibit an anomaly in the absorption. A plausible interpretation of the anomaly is that some of the interactions are caused by neutrinos. We infer that the cross section of neutrino-nucleon interactions is approximately 6 mb at energies of a few PeV, significantly exceeding the prediction of the standard model.

Breakdown of scaling in high-energy accelerator and cosmic-ray interactions

There is still argument about the extent to which the simple description of high energy nucleon-nucleon interactions first put forward by Feynman (1969) (Feynman 'scaling') is valid above about 1012 eV. The authors examine the latest data from the CERN pp experiments, which relate to equivalent laboratory energies up to approximately=4*1014 eV ( square root s=900 GeV), and cosmic-ray phenomena at similar energies, and coincide that the evidence for a breakdown of scaling is still strong.

Searching for supersymmetry in high-energy cosmic-ray interactions.

We survey the prospects for producing and detecting supersymmetric particles in high-energy cosmic-ray interactions. We find that the production and subsequent decay of light (approx.3 GeV) gluinos can lead to fluxes of neutral, weakly interacting superparticles, photinos or scalar neutrinos, which might be detected in large, underwater neutrino detectors. We identify several reactions, gamma-tildeN..-->..gqX in the 10--100-TeV region and the resonant process nu-tilde/sub e/e/sup -/..-->..W/sup -/, which can lead to measurable reaction rates in the discussed 10/sup 5/-kiloton DUMAND-type detector.

Formation and signature of quark matter in relativistic ion collisions

Exclusively using experimental information on particle production in nucleon-nucleon interactions, this paper attempts to demonstrate that: (i) the characteristics of relativistic collisions between heavy nuclei are determined by quark physics, not conventional nuclear physics; (ii) the formation of quark matter in such collisions can be observed experimentally via large multiplicities, copious production of photons (not from π decay), the anomalous strangeness, charm and baryon number structure of the events, and appearance of structure in the rapidity distribution; (iii) the formation of quark matter has actually been observed in high energy cosmic ray interactions. We show that the 100 TeV threshold for the appearance of anomalous interactions reflects the transition from nucleonic to quark structure of the nucleus. Observed anomalies match the signatures of quark matter formation in (ii); (iv) our results imply the abundant presence of heavy nuclei, e.g. Fe, in the high energy cosmic ray spectrum. Cosmic ray interactions above 100 TeV can eventually be used to study the vacuum structure of quantum chromodynamics and the disappearance of spontaneous symmetry breaking due to the restoration of symmetry at high matter densities.