PRODUCTION OF COSMIC RAY MESONS AT LARGE ZENITH ANGLES

1956 ◽  
Vol 34 (5) ◽  
pp. 432-450 ◽  
Author(s):  
D. Jakeman
Keyword(s):  
Meson Production ◽  
Cosmic Ray ◽  
Absolute Intensity ◽  
Horizontal Direction ◽  
Air Showers ◽  
K Meson ◽  
Production Spectrum ◽  
A Value ◽  
Selection Of ◽  
Calculated Intensity

Events have been selected by coincidences between separated shielded trays of Geiger counters and it is shown that they arise from three types of phenomena, namely, extensive air showers, casual coincidences, and particles travelling in almost a horizontal direction. Selection of the last type of event has enabled the absolute intensity to be determined at zenith angles between 88° and 90°. Using a π meson production spectrum which gives consistency with the established underground absorption curve the intensity of particles in the horizontal direction has been calculated on the assumption that π–μ decay is the only source of μ mesons. The calculated intensity agrees well with the observations. Alternatively, by comparing the rate in the horizontal direction with the known rate underground, a value of 4.5 ± 1.5 × 10−8 sec. is obtained for the lifetime of the parents of μ mesons which, because of the depth of the atmosphere in the horizontal direction (362 m.w.e.), must have energy exceeding 1011 ev. This suggests that at this energy the parents of μ mesons can be identified with the π meson, and the number of μ mesons arising from the decay of a shorter lived meson (e.g. K meson) must be relatively small.

Sea-level cosmic ray spectra at large zenith angles

1961 ◽  
Vol 265 (1320) ◽  
pp. 117-132 ◽  
Keyword(s):  
Sea Level ◽  
Meson Production ◽  
Cosmic Ray ◽  
Great Accuracy ◽  
Statistical Fluctuation ◽  
Momentum Range ◽  
Production Spectrum ◽  
A Value ◽  
The Mean ◽  
Particle Intensity

Measurements have been made at Durham (200ft. above sea level) with an emulsion spectrograph of the absolute cosmic ray particle intensity in the momentum range 1 to 100 GeV/ c at zenith angles of between 65° and 85°. It is found that a differential π-meson production spectrum of the form I 0 E -y fits closely the present results as well as the accepted vertical spectrum. The values of the parameters when E lies between 6 and 1000 GeV are given by the equations I 0 = 0.425 — 01.25 log 10 E and y = 3.92 — 0.944 (1 — 0.125 log 10 E ) -1 and their approximate constant values in this range are 0T5 and 2*55 respectively. The analysis is based on the model of Barrett, Bollinger, Cocconi, Eisenberg & Greisen (1952) but, in addition, the effects of scattering and geomagnetic deflexion of u-mesons in the atmosphere have been taken into account as well as their production over a range of atmospheric depths. Although in principle it should be possible from the form of the sea-level spectra at large zenith angles to determine the relative numbers of π- and K -mesons at production, it is shown that very great accuracy is required in order to do so. Nevertheless, the agreement between the theoretical curves and the experimental measurements indicates that the main assumptions concerning the production and propagation of mesons in the atmosphere are correct. The mean positive to negative ratio is 1.39±0.08, a value rather larger than is found by other observers at 68°, but within statistical fluctuation.

scholarly journals Highlights from HAWC

2019 ◽  
Vol 208 ◽  
pp. 14001
Author(s):  
H. León Vargas
Keyword(s):  
Energy Range ◽  
High Altitude ◽  
High Precision ◽  
Gamma Rays ◽  
Large Data ◽  
Cosmic Ray ◽  
Air Showers ◽  
Data Set ◽  
Sierra Negra Volcano ◽  
Selection Of

The HAWC (High Altitude Water Cherenkov) observatory, located on the slopes of the Sierra Negra volcano in the state of Puebla, Mexico, was designed with the goal of detecting gamma-rays in the Teraelectron- volt energy range. However, most of the air showers that are detected with the observatory, with a rate of ≈ 27 kHz, are of hadronic origin. This makes that, after three years of operations, HAWC has accumulated a very large data set that allows to perform cosmic-ray analysis of high precision. The details of the observatory operation, as well as a selection of recent results in cosmic-ray physics are discussed in this work.

scholarly journals Production and Interaction of High Energy Neutrinos in Close X-ray Binaries

1987 ◽  
Vol 125 ◽  
pp. 552-552
Author(s):  
A. K. Harding ◽  
J. J. Barnard ◽  
F. W. Stecker ◽  
T. K. Gaisser
Keyword(s):  
Cross Sections ◽  
Energy Deposition ◽  
Binary Systems ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Air Showers ◽  
Companion Star ◽  
Production Spectrum ◽  
Neutrino Absorption

Reports of air showers with E > 1015 eV from Cygnus X-3, LMC X-4, Vela X-1 and Hercules X-1 have been interpreted as requiring production of neutral secondaries by cosmic rays accelerated by the compact partner in these systems. If neutral pions are the source of photons that produce the observed air showers, then charged pions must also be produced, and they will give rise to neutrinos. We consider limits that may be placed on binary systems like Cygnus X-3 in which a neutron star is a strong source of ultra-high energy (UHE) particles that produce photons, neutrinos and other secondary particles in the companion star through nuclear interactions. The highest energy neutrinos (> 1 TeV), which have the largest interaction cross sections, are absorbed deep in the companion. From a detailed numerical calculation of the hadronic cascade induced in the atmosphere of the companion star, we estimate the neutrino production spectrum from an isotropic flux of monoenergetic 1017 eV protons and we estimate the resulting neutrino absorption in the stellar core. In the case of Cyg X-3 and LMC X-4, the cosmic-ray luminosities required to produce the observed gamma rays would result in energy deposition from neutrino absorption exceeding the intrinsic stellar luminosity of the companion. Over a timescale of 104−105 yr, the star would absorb its own binding energy and be disrupted. On shorter timescales, the energy deposition will cause significant expansion of the star, perhaps leading to quenching of high-energy signals from the source. From these results, we conclude that systems requiring intense UHE proton fluxes are either very young or the companion star is not the site of observed gamma-ray production. Alternatively, if the gamma-ray source is highly variable, the proton flux requirements would be lower, providing some relaxation of the above constraints.[See Gaisser et al. 1986, Ap. J. (Oct. 15), in press].

A Selection of Bandung City Travel Route Using The FLOYD-WARSHALL Algorithm

2020 ◽  
Vol 12 (7) ◽  
Author(s):  
Muhammad Ghifari Arfananda ◽  
◽  
Surya Michrandi Nasution ◽  
Casi Setianingsih ◽  
◽  
...  
Keyword(s):  
Traffic Congestion ◽  
Rapid Development ◽  
Route Selection ◽  
Tourist Attractions ◽  
Tourist Destinations ◽  
A Value ◽  
Distance Data ◽  
Simple Additive Weighting ◽  
The City ◽  
Selection Of

The rapid development of information and technology, the city of Bandung tourism has also increased. However, tourists who visit the city of Bandung have problems with a limited time when visiting Bandung tourist attractions. Traffic congestion, distance, and the number of tourist destinations are the problems for tourists travel. The optimal route selection is the solution for those problems. Congestion and distance data are processed using the Simple Additive Weighting (SAW) method. Route selection uses the Floyd-Warshall Algorithm. In this study, the selection of the best route gets the smallest weight with a value of 5.127 from the Algorithm process. Based on testing, from two to five tourist attractions get an average calculation time of 3 to 5 seconds. This application is expected to provide optimal solutions for tourists in the selection of tourist travel routes.

Identifikation und Auswahl von Business Ecosystems*/Identification and selection of business ecosystems. Procedure and strategic and operative integration in industrial companies

2019 ◽  
Vol 109 (04) ◽  
pp. 294-301
Author(s):  
R. E. Geitner ◽  
T. Bauernhansl
Keyword(s):  
Value Proposition ◽  
Business Ecosystem ◽  
Industrial Companies ◽  
A Value ◽  
Basic Procedure ◽  
Business Ecosystems ◽  
Value Propositions ◽  
Operational Integration ◽  
A Company ◽  
Selection Of

Die fortschreitende Digitalisierung führt zu neuen und konvergierenden Produkt- und Dienstleistungen und effizienteren Prozessen. In Verbindung mit einem Wandel der Bedürfnisse führt sie darüber hinaus auch zu einem veränderten Nutzerverhalten und Nutzenverständnis der Kunden. Zur flexiblen und schnellen Umsetzung von passgenau individualisierten, oft branchenübergreifenden Wertangeboten und der Absicherung des Kundenzugangs wird es zukünftig wettbewerbsentscheidend sein, sich im richtigen Business Ecosystem – also der Gruppe von Akteuren die interagieren müssen, um ein entsprechendes Wertangebot zu realisieren und den entsprechenden Kundenzugang haben – zu bewegen und dieses mitzugestalten. Der Beitrag beschreibt das grundsätzliche Vorgehen zur Identifizierung und Auswahl relevanter Business Ecosystems sowie deren strategische und operative Einbindung in ein Unternehmen.   The ongoing digitization leads to new and converging product benefits and more efficient processes. In connection with a change in needs it also leads to a change in user behaviour and understanding of the benefits for customers. For the flexible and fast implementation of customized, individualized, often cross-industry value propositions and the safeguarding of access to customers, it will be crucial in the future to act and help to shape the relevant business ecosystems (group of actors that need to interact in order to realize a value proposition or to have access to customers). The article describes the basic procedure for identifying and selecting relevant business ecosystems and their strategic and operational integration into a company.

Distribution of arrival times in cosmic ray showers

1978 ◽  
Vol 10 (4) ◽  
pp. 730-735
Author(s):  
H. S. Green
Keyword(s):  
Cosmic Radiation ◽  
Three Dimensional ◽  
Stochastic Theory ◽  
Cosmic Ray ◽  
Time Of Arrival ◽  
Air Showers ◽  
Actual Distribution ◽  
Arrival Times ◽  
Primary Particles ◽  
Theoretical Analyses

The theoretical analyses of the extensive air showers developing from the cosmic radiation has its origins in the work of Carlson and Oppenheimer (1937) and Bhabha and Heitler (1937), at a time when it was thought that such showers were initiated by electrons. The realization that protons and other nuclei were the primary particles led to a reformulation of the theory by Heitler and Janossy (1949), Messel and Green (1952) and others, in which the production of energetic pions and the three-dimensional development of air showers were accounted for. But as the soft (electromagnetic) component of the cosmic radiation is the most prominent feature of air showers at sea level, there has been a sustained interest in the theory of this component. Most of the more recent work, such as that by Butcher and Messel (1960) and Thielheim and Zöllner (1972) has relied on computer simulation; but this method has disadvantages in terms of accuracy and presentation of results, especially where a simultaneous analysis of the development of air showers in terms of several physical variables is required. This is so for instance when the time of arrival is one of the variables. Moyal (1956) played an important part in the analytical formulation of a stochastic theory of cosmic ray showers, with time as an explicit variable, and it is essentially this approach which will be adopted in the following. The actual distribution of arrival times is cosmic ray showers, for which results are obtained, is of current experimental interest (McDonald, Clay and Prescott (1977)).

scholarly journals Cosmic-Ray Extremely Distributed Observatory: Status and Perspectives

Universe ◽  
2018 ◽  
Vol 4 (11) ◽  
pp. 111 ◽  
Author(s):  
Dariusz Góra
Keyword(s):  
Time Window ◽  
Cosmic Ray ◽  
Small Time ◽  
Global Studies ◽  
Active Engagement ◽  
Air Showers ◽  
Fundamental Physics ◽  
Terra Incognita ◽  
The Status ◽  
Worldwide Network

The Cosmic-Ray Extremely Distributed Observatory (CREDO) is a project dedicated to global studies of extremely extended cosmic-ray phenomena, the cosmic-ray ensembles (CRE), beyond the capabilities of existing detectors and observatories. Up to date, cosmic-ray research has been focused on detecting single air showers, while the search for ensembles of cosmic-rays, which may overspread a significant fraction of the Earth, is a scientific terra incognita. Instead of developing and commissioning a completely new global detector infrastructure, CREDO proposes approaching the global cosmic-ray analysis objectives with all types of available detectors, from professional to pocket size, merged into a worldwide network. With such a network it is possible to search for evidences of correlated cosmic-ray ensembles. One of the observables that can be investigated in CREDO is a number of spatially isolated events collected in a small time window which could shed light on fundamental physics issues. The CREDO mission and strategy requires active engagement of a large number of participants, also non-experts, who will contribute to the project by using common electronic devices (e.g., smartphones). In this note, the status and perspectives of the project are presented.

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