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‣ Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

ABREU, P.; AGLIETTA, M.; AHN, E. J.; Albuquerque, Ivone Freire da Mota e; ALLARD, D.; ALLEKOTTE, I.; ALLEN, J.; ALLISON, P.; CASTILO, J. Alvarez; ALVAREZ-MUNIZ, J.; AMBROSIO, M.; AMINAEI, A.; ANCHORDOQUI, L.; ANDRINGA, S.; ANTICIC, T.; ANZALONE, A.; ARAMO
Fonte: IOP PUBLISHING LTD Publicador: IOP PUBLISHING LTD
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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The Pierre Auger Collaboration has reported. evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > E(th) = 5.5 x 10(19) eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > E(th) are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above E(th)/Z (for illustrative values of Z = 6, 13, 26). If the anisotropies above E(th) are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.; Comision Nacional de Energia Atomica; Comision Nacional de Energia Atomica; Fundacion Antorchas; Fundacion Antorchas; Gobierno De La Provincia de Mendoza; Gobierno De La Provincia de Mendoza; Municipalidad de Malargue; Municipalidad de Malargue; NDM Holdings; NDM Holdings; Valle Las Lenas; Valle Las Lenas; Australian Research Council (ARC); Australian Research Council; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq); Financiadora de Estudos e Projetos (FINEP); Financiadora de Estudos e Projetos (FINEP); Fundacao de Amparo a Pesquisa do Estado de Rio de Janeiro (FAPERJ); Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Ministério da Ciência...

‣ Future directions in astroparticle physics and the AUGER experiment

Dova, Maria Teresa
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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The observation of cosmic ray particles with unexpected high energies is pushing astroparticle physics into a period of rapid progress both theoretically and experimentally. Different proposed models for the generation of these particles are constrained by the absence of the predicted GZK cutoff in the cosmic ray spectrum and by the composition and the distribution of arrival directions observed. The database increase due to the Pierre Auger Observatory will provide a clearer picture of the spectral anisotropy and properties of such high energy particles, enabling tests of their origin and nature.; Comment: Invited talk at the XXXth Int. Symposium on Multiparticle Dynamics (ISMD 2000), 9-15 October 2000, Tihany, Hungary. To be published by World Scientific (2001) (style file ws-p8-50x6-00.cls included)

‣ Gamma ray astroparticle physics with GLAST

Morselli, Aldo
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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The energy domain between 10 MeV and hundreds of GeV is an essential one for the multifrequency study of extreme astrophysical sources. The understanding of spectra of detected gamma rays is necessary for developing models for acceleration, emission, absorption and propagation of very high energy particles at their sources and in space. After the end of EGRET on board the Compton Gamma Ray Observatory this energy region is not covered by any other experiment, at least up to 50 GeV where ground Cerenkov telescopes are beginning to take data. Here we will review the status of the space experiment GLAST that will fill this energy region from March 2006 with particular emphasis at the connection with all the other ground and space planned experiments and at the contribution of GLAST to particle physics.; Comment: 18 pages, 16 figures, Proceedings of International School of Space Science, 2001 Course on Astroparticle and gamma-ray physics in space. Replacement: references added

‣ Frontiers in High-Energy Astroparticle Physics

Mannheim, Karl
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 12/02/1999 Português
Relevância na Pesquisa
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With the discovery of evidence for neutrino mass, a vivid gamma ray sky at multi-TeV energies, and cosmic ray particles with unexpectedly high energies, astroparticle physics currently runs through an era of rapid progress and moving frontiers. The non-vanishing neutrino mass establishes one smooth component of dark matter which does not, however, supply a critical mass to the Universe. Other dark matter particles are likely to be very massive and should produce high-energy gamma rays, neutrinos, and protons in annihilations or decays. The search for exotic relics with new gamma ray telescopes, extensive air shower arrays, and underwater/-ice neutrino telescopes is a fascinating challenge, but requires to understand the astrophysical background radiations at high energies. Among the high-energy sources in the Universe, radio-loud active galactic nuclei seem to be the most powerful accounting for at least a sizable fraction of the extragalactic gamma ray flux. They could also supply the bulk of the observed cosmic rays at ultrahigh energies and produce interesting event rates in neutrino telescopes aiming at the kubic kilometer scale such as AMANDA and ANTARES. It is proposed that the extragalactic neutrino beam can be used to search for tau lepton appearance thus allowing for a proof of the neutrino oscillation hypothesis. Furthermore...

‣ Very-high energy gamma-ray astronomy: A 23-year success story in high-energy astroparticle physics

Lorenz, Eckart; Wagner, Robert
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 25/07/2012 Português
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Very-high energy (VHE) gamma quanta contribute only a minuscule fraction - below one per million - to the flux of cosmic rays. Nevertheless, being neutral particles they are currently the best "messengers" of processes from the relativistic/ultra-relativistic Universe because they can be extrapolated back to their origin. The window of VHE gamma rays was opened only in 1989 by the Whipple collaboration, reporting the observation of TeV gamma rays from the Crab nebula. After a slow start, this new field of research is now rapidly expanding with the discovery of more than 150 VHE gamma-ray emitting sources. Progress is intimately related with the steady improvement of detectors and rapidly increasing computing power. We give an overview of the early attempts before and around 1989 and the progress after the pioneering work of the Whipple collaboration. The main focus of this article is on the development of experimental techniques for Earth-bound gamma-ray detectors; consequently, more emphasis is given to those experiments that made an initial breakthrough rather than to the successors which often had and have a similar (sometimes even higher) scientific output as the pioneering experiments. The considered energy threshold is about 30 GeV. At lower energies...

‣ Unification and Model Building, Astroparticle Physics and Neutrinos

Raychaudhuri, Amitava; Roy, Probir
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 11/04/1996 Português
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This report summarises the work done during the Workshop on High Energy Physics Phenomenology 4 (S.N.Bose National Centre for Basic Sciences, Calcutta, India, Jan 2-14,1996) in Working Groups IV (Unification and Model Building) and V (Astroparticle Physics and Neutrinos).; Comment: Working group report, 9 pages, latex, no figures

‣ Gamma rays from the Galactic Centre region: a review

van Eldik, Christopher
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 22/05/2015 Português
Relevância na Pesquisa
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During the last decades, increasingly precise astronomical observations of the Galactic Centre (GC) region at radio, infrared, and X-ray wavelengths laid the foundations to a detailed understanding of the high energy astroparticle physics of this most remarkable location in the Galaxy. Recently, observations of this region in high energy (HE, 10 MeV - 100GeV) and very high energy (VHE, > 100 GeV) gamma rays added important insights to the emerging picture of the Galactic nucleus as a most violent and active region where acceleration of particles to very high energies -- possibly up to a PeV -- and their transport can be studied in great detail. Moreover, the inner Galaxy is believed to host large concentrations of dark matter (DM), and is therefore one of the prime targets for the indirect search for gamma rays from annihilating or decaying dark matter particles. In this article, the current understanding of the gamma-ray emission emanating from the GC is summarised and the results of recent DM searches in HE and VHE gamma rays are reviewed.; Comment: invited review, accepted for publication in Astroparticle Physics

‣ Astroparticle Physics

Magnussen, Norbert
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 04/11/1999 Português
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This article reviews some recent developments in Astroparticle Physics. Due to the extension of the field only part of the results and developments can be covered. The status of the search for Dark Matter, some recent results on Cosmic Rays and Gamma Ray Astronomy and the status of Neutrino Astronomy are presented.; Comment: 20 pages, 18 figures; Invited talk at the International Europhysics Conference on High Energy Physics, Tampere, Finland, 15-21 July 1999. To appear in Conf. Proceedings edited by K. Huitu, H. Kurki-Suonio and J. Maalampi (IOP Publishing, Bristol, UK)

‣ Atmospheric effects in astroparticle physics experiments and the challenge of ever greater precision in measurements

Louedec, K.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 12/03/2014 Português
Relevância na Pesquisa
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Astroparticle physics and cosmology allow us to scan the universe through multiple messengers. It is the combination of these probes that improves our understanding of the universe, both in its composition and its dynamics. Unlike other areas in science, research in astroparticle physics has a real originality in detection techniques, in infrastructure locations, and in the observed physical phenomenon that is not created directly by humans. It is these features that make the minimisation of statistical and systematic errors a perpetual challenge. In all these projects, the environment is turned into a detector medium or a target. The atmosphere is probably the environment component the most common in astroparticle physics and requires a continuous monitoring of its properties to minimise as much as possible the systematic uncertainties associated. This paper introduces the different atmospheric effects to take into account in astroparticle physics measurements and provides a non-exhaustive list of techniques and instruments to monitor the different elements composing the atmosphere. A discussion on the close link between astroparticle physics and Earth sciences ends this paper.; Comment: 27 pages, 8 figures, review paper, submitted to Astroparticle Physics

‣ High-Energy Neutrino Astronomy: Opportunities For Particle Physics

Hooper, Dan
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 21/01/2004 Português
Relevância na Pesquisa
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In this article, based on the talk given at the Cracow Epiphany Conference on Astroparticle Physics, I discuss some of the opportunities provided by high-energy and ultra-high energy neutrino astronomy in probing particle physics beyond the standard model. Following a short summary of current and next generation experiments, I review the prospects for observations of high-energy neutrino interactions, searches for particle dark matter, and measurements of absolute neutrino masses, lifetimes and pseudo-Dirac mass splittings.; Comment: Based on review talk given at the 2004 Cracow Epiphany Conference on Astroparticle Physics

‣ A fundamental theory based on the Monte Carlo \textit{Time Sequential Procedure} for the range fluctuations of high energy muons

Okumura, Yoshihide; Takahashi, Nobusuke; Misaki, Akeo
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
708.3475%
Lipari and Stanev developed a method for range fluctuation of high energy muons, stressing the importance of accounting for the fluctuations of the energy loss in radiative processes in 1991 and, now, their method has become the basement for the energy determination of high energy muons through the measurement of the Cherenkov light yields due to those muons in KM3 physics. Once, Takahashi et al. developed a method for the investigation on the depth intensity relation of high energy muons in which all the stochastic processes concerned are taken into account exactly (1983). Now, we make the method by Takahashi et al. revival for the same purpose of the application to the analysis of future KM3 physics. In the present paper, our concern is restricted to the introduction to the fundamental of our method and some subsequent results thereby in which the real simulated behaviors of high energy muons from $10^{12}$eV to $10^{18}$eV, the survival probabilities of high energy and so on are included. The discussion around the practical application of our method to the KM3 physics is entrusted in the subsequent papers. As far as the survival probability of high energy muons is concerned, our method gives nearly the same results to Lipari and Stanev's in some regions and gives the deviated results from theirs in another ones. Thus...

‣ High Energy Astroparticle Physics

Sigl, Guenter
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 09/12/2006 Português
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We give a brief (and highly incomplete) overview of the current experimental and theoretical status of high energy cosmic rays and their secondary gamma-rays and neutrinos. We focus on the role of large scale magnetic fields and on multi-messenger aspects linking these three channels. We also recall that the flavor composition of neutrino fluxes from astrophysical sources contains information on both the source conditions and neutrino physics.; Comment: 6 papes, 2 figures, proceedings of plenary talk at the Neutrino Oscillation Workshop (NOW 2006), Conca Specchiulla, Italy, September 9-16, 2006

‣ Working Group Report: Neutrino and Astroparticle Physics

Goswami, Srubabati; Rangarajan, Raghavan; Agashe, K.; Bandyopadhyay, A.; Bhattacharya, K.; Brahmachari, B.; Burgess, C.; Chun, E. J.; Choudhury, D.; Das, P. K.; Dighe, A.; Godbole, R.; Gupta, N.; Kaplinghat, M.; Indumathi, D.; Forshaw, J.; Keum, Y. Y.; La
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 19/09/2004 Português
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This is the report of neutrino and astroparticle physics working group at WHEPP-8. We present the discussions carried out during the workshop on selected topics in the above fields and also indicate progress made subsequently. The neutrino physics subgroup studied the possibilites of constraining neutrino masses, mixing and CPT violation in lepton sector from future experiments. Neutrino mass models in the context of abelian horizontal symmetries, warped extra dimensions and in presence of triplet Higgs were studied. Effect of threshold corrections on radiative magnification of mixing angles was investigated. The astroparticle physics subgroup focused on how various particle physics inputs affect the CMBR fluctuation spectrum, and on brane cosmology. This report also contains an introduction on how to use the publicly available code CMBFAST to calculate the CMBR fluctuations.; Comment: Prepared for the 8th Workshop on High-Energy Physics Phenomenology (WHEPP-8), IIT Mumbai, India, 5-16 Jan 2004

‣ High-energy astroparticle physics with CALET

Maestro, Paolo
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 05/02/2013 Português
Relevância na Pesquisa
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The CALorimetric Electron Telescope (CALET) will be installed on the Exposure Facility of the Japanese Experiment Module (JEM-EF) on the International Space Station (ISS) in 2014 where it will measure the cosmic-ray fluxes for five years. Its main scientific goals are to search for dark matter, investigate the mechanism of cosmic-ray acceleration and propagation in the Galaxy and discover possible astrophysical sources of high-energy electrons nearby the Earth. The instrument, under construction, consists of two layers of segmented plastic scintillators for the cosmic-ray charge identification (CHD), a 3 X$_0$-thick tungsten-scintillating fiber imaging calorimeter (IMC) and a 27 X$_0$-thick lead-tungstate calorimeter (TASC). The CHD can provide single-element separation in the interval of atomic number Z from 1 to 40, while IMC and TASC can measure the energy of cosmic-ray particles with excellent resolution in the range from few GeV up to several hundreds of TeV. Moreover, IMC and TASC provide the longitudinal and lateral development of the shower, a key issue for good electron/hadron discrimination. In this paper, we will review the status of the mission, the instrument configuration and its expected performance, and the CALET capability to measure the different components of the cosmic radiation.; Comment: 4 pages...

‣ Effect of neutral current interactions on high energy muon and electron neutrino propagation through the Earth

Labbate, Annalisa; Montaruli, Teresa; Sokalski, Igor
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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High energy electron and muon neutrino propagation through the Earth has been performed using the Monte Carlo technique. We focused our attention on the effect of neutral current deep inelastic interactions compared to that of charged current ones. We have found that NCs do not produce any significant effect with respect to the case in which only CCs are considered. Therefore we conclude that NC interactions can be neglected without considerable loss of accuracy. When computing upward-going neutrino fluxes a simple formula describing the transmission probability, that depends on the neutrino direction and energy and the CC cross section, can be used to account for the Earth shadowing effect.; Comment: 9 pages, 4 figures, uses elsart.cls, elsart.sty, elsart12.sty, submitted to Astroparticle Physycs. The version 3 has been significantly changed in the frame of preparation for publication in Astroparticle Physics: new plot and references added, several misprinting have been fixed

‣ High-energy astroparticle physics

Semikoz, D.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 13/10/2010 Português
Relevância na Pesquisa
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In these three lectures I discuss the present status of high-energy astroparticle physics including Ultra-High-Energy Cosmic Rays (UHECR), high-energy gamma rays, and neutrinos. The first lecture is devoted to ultra-high-energy cosmic rays. After a brief introduction to UHECR I discuss the acceleration of charged particles to highest energies in the astrophysical objects, their propagation in the intergalactic space, recent observational results by the Auger and HiRes experiments, anisotropies of UHECR arrival directions, and secondary gamma rays produced by UHECR. In the second lecture I review recent results on TeV gamma rays. After a short introduction to detection techniques, I discuss recent exciting results of the H.E.S.S., MAGIC, and Milagro experiments on the point-like and diffuse sources of TeV gamma rays. A special section is devoted to the detection of extragalactic magnetic fields with TeV gamma-ray measurements. Finally, in the third lecture I discuss Ultra-High-Energy (UHE) neutrinos. I review three different UHE neutrino detection techniques and show the present status of searches for diffuse neutrino flux and point sources of neutrinos.; Comment: 29 pages, Lectures given at the 5th CERN-Latin-American School of High-Energy Physics...

‣ Towards a Model for Computing in European Astroparticle Physics

Berghöfer, T.; Agrafioti, I.; Allen, B.; Beckmann, V.; Chiarusi, T.; Delfino, M.; Hesping, S.; Chudoba, J.; Dell'Agnello, L.; Katsanevas, S.; Lamanna, G.; Lemrani, R.; Margiotta, A.; Maron, G.; Palomba, C.; Russo, G.; Wegner, P.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 03/12/2015 Português
Relevância na Pesquisa
732.26016%
Current and future astroparticle physics experiments are operated or are being built to observe highly energetic particles, high energy electromagnetic radiation and gravitational waves originating from all kinds of cosmic sources. The data volumes taken by the experiments are large and expected to grow significantly during the coming years. This is a result of advanced research possibilities and improved detector technology. To cope with the substantially increasing data volumes of astroparticle physics projects it is important to understand the future needs for computing resources in this field. Providing these resources constitutes a larger fraction of the overall running costs of future infrastructures. This document presents the results of a survey made by APPEC with the help of computing experts of major projects and future initiatives in astroparticle physics, representatives of current Tier-1 and Tier-2 LHC computing centers, as well as specifically astroparticle physics computing centers, e.g. the Albert Einstein Institute for gravitational waves analysis in Hanover. In summary, the overall CPU usage and short-term disk and long-term (tape) storage space currently available for astroparticle physics projects' computing services is of the order of one third of the central computing available for LHC data at the Tier-0 center at CERN. Till the end of the decade the requirements for computing resources are estimated to increase by a factor of 10. Furthermore...

‣ Project of Virtual Institute of Astroparticle Physics

Khlopov, M. Yu.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 02/01/2008 Português
Relevância na Pesquisa
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Studies in astroparticle physics are actively developed all over the world. It is clear that the effectiveness of the work depends strongly on the information exchange rate and on the overall coordination of this activity. An international forum, be it virtual, which can join all the groups and coordinate their efforts would give a boost to this cooperation. Particularly this is important for isolated scientific groups and scientists from small countries which can contribute a lot to this work being a part of the large international collaboration. Objectives, instruments and structure of proposed Virtual Instutute of Astroparticle Physics are discussed.; Comment: Prepared for Proceedings of Blois2007 Conference

‣ High energy astroparticle physics for high school students

Krause, Maria; Bretz, Hans-Peter; Classen, Lew; Holler, Markus; Hütten, Moritz; Raab, Susanne; Rautenberg, Julian; Schulz, Anneli
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 17/08/2015 Português
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The questions about the origin and type of cosmic particles are not only fascinating for scientists in astrophysics, but also for young enthusiastic high school students. To familiarize them with research in astroparticle physics, the Pierre Auger Collaboration agreed to make 1% of its data publicly available. The Pierre Auger Observatory investigates cosmic rays at the highest energies and consists of more than 1600 water Cherenkov detectors, located near Malarg\"{u}e, Argentina. With publicly available data from the experiment, students can perform their own hands-on analysis. In the framework of a so-called Astroparticle Masterclass organized alongside the context of the German outreach network Netzwerk Teilchenwelt, students get a valuable insight into cosmic ray physics and scientific research concepts. We present the project and experiences with students.; Comment: 8 pages, 5 figures, Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands, PoS(ICRC2015)304

‣ AtmoHEAD 2013 workshop / Atmospheric Monitoring for High-Energy Astroparticle Detectors

Bernlöhr, K.; Bellassai, G.; Blanch, O.; Bourgeat, M.; Bruno, P.; Buscemi, M.; Cassardo, C.; Chadwick, P. M.; Chalme-Calvet, R.; Chouza, F.; Cilmo, M.; Coco, M.; Colombi, J.; Compin, M.; Daniel, M. K.; Reyes, R. De Los; Ebr, J.; D'Elia, R.; Deil, C.; Etc
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 19/03/2014 Português
Relevância na Pesquisa
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A 3-day international workshop on atmospheric monitoring and calibration for high-energy astroparticle detectors, with a view towards next-generation facilities. The atmosphere is an integral component of many high-energy astroparticle detectors. Imaging atmospheric Cherenkov telescopes and cosmic-ray extensive air shower detectors are the two instruments driving the rapidly evolving fields of very-high- and ultra-high-energy astrophysics. In these instruments, the atmosphere is used as a giant calorimeter where cosmic rays and gamma rays deposit their energy and initiate EASs; it is also the medium through which the resulting Cherenkov light propagates. Uncertainties in real-time atmospheric conditions and in the fixed atmospheric models typically dominate all other systematic errors. With the improved sensitivity of upgraded IACTs such as H.E.S.S.-II and MAGIC-II and future facilities like the Cherenkov Telescope Array (CTA) and JEM-EUSO, statistical uncertainties are expected to be significantly reduced, leaving the atmosphere as the limiting factor in the determination of astroparticle spectra. Varying weather conditions necessitate the development of suitable atmospheric monitoring to be integrated in the overall instrument calibration...