Comparison of surface integral equations for left-handed materials

A wide analysis of left-handed material (LHM) spheres with di®erent constitutive parameters has been carried out employ- ing di®erent integral-equation formulations based on the Method of Moments. The study is focused on the accuracy assessment of for- mulations combining normal equations (combined normal formula- tion, CNF), tangential equations (combined tangential formulation, CTF, and Poggio-Miller-Chang-Harrington-Wu-Tsai formulation, PM- CHWT) and both of them (electric and magnetic current combined ¯eld integral equation, JMCFIE) when dealing with LHM's. Relevant and informative features as the condition number, the eigenvalues dis- tribution and the iterative response are analyzed. The obtained results show up the suitability of the JMCFIE for this kind of analysis in con- trast with the unreliable behavior of the other approaches.Ministerio de Ciencia e Innovación | Ref. TEC2008-06714-C02-01Ministerio de Ciencia e Innovación | Ref. TEC2008-06714-C02-02Ministerio de Ciencia e Innovación | Ref. CSD2008-00068Xunta de Galicia | Ref. INCITE08PXIB322250P

Multiple Scenario Generation of Subsurface Models:Consistent Integration of Information from Geophysical and Geological Data throuh Combination of Probabilistic Inverse Problem Theory and Geostatistics

Neutrinos with energies above 1017 eV are detectable with the Surface Detector Array of the Pierre Auger Observatory. The identification is efficiently performed for neutrinos of all flavors interacting in the atmosphere at large zenith angles, as well as for Earth-skimming \u3c4 neutrinos with nearly tangential trajectories relative to the Earth. No neutrino candidates were found in 3c 14.7 years of data taken up to 31 August 2018. This leads to restrictive upper bounds on their flux. The 90% C.L. single-flavor limit to the diffuse flux of ultra-high-energy neutrinos with an E\u3bd-2 spectrum in the energy range 1.0 7 1017 eV -2.5 7 1019 eV is E2 dN\u3bd/dE\u3bd < 4.4 7 10-9 GeV cm-2 s-1 sr-1, placing strong constraints on several models of neutrino production at EeV energies and on the properties of the sources of ultra-high-energy cosmic rays

Measurement of the Fluctuations in the Number of Muons in Extensive Air Showers with the Pierre Auger Observatory

The successful installation, commissioning, and operation of the Pierre Auger Observatory would not have been possible without the strong commitment and effort from the technical and administrative staff in Malargue. We are very grateful to the following agencies and organizations for financial support: Argentina-Comision Nacional de Energia Atomica, Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Gobierno de la Provincia de Mendoza, Municipalidad de Malargue, NDM Holdings and Valle Las Lenas; in gratitude for their continuing cooperation over land access; Australia-the Australian Research Council; BrazilConselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Financiadora de Estudos e Projetos (FINEP), Fundacao de Amparo a Pesquisa do Estado de Rio de Janeiro (FAPERJ), Sao Paulo Research Foundation (FAPESP) Grants No. 2019/10151-2, No. 2010/07359-6, and No. 1999/05404-3, Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes (MCTIC); Ministry of Education, Youth and Sports of the Czech RepublicGrants No. MSMT CR LTT18004, No. LM2015038, No. LM2018102, No. CZ.02.1.01/0.0/0.0/16_013/0001402, No. CZ.02.1.01/0.0/0.0/18_046/0016010, and No. CZ.02.1.01/0.0/0.0/17_049/0008422; France-Centre de Calcul IN2P3/CNRS, Centre National de la Recherche Scientifique (CNRS), Conseil Regional Ile-de-France, Departement Physique Nucl ' eaire et Corpusculaire (PNC-IN2P3/CNRS), Departement Sciences de l'Univers (SDU-INSU/CNRS), Institut Lagrange de Paris (ILP) Grant No. LABEX ANR-10-LABX-63 within the Investissements d'Avenir Programme Grant No. ANR11-IDEX-0004-02; Germany-Bundesministerium fur Bildung und Forschung (BMBF), Deutsche Forschungsgemeinschaft (DFG), Finanzministerium Baden-Wurttemberg, Helmholtz Alliance for Astroparticle Physics (HAP), Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF), Ministerium fur Innovation, Wissenschaft und Forschung des Landes Nordrhein-Westfalen, Ministerium fur Wissenschaft, Forschung und Kunst des Landes Baden-Wurttemberg; Italy-Istituto Nazionale di Fisica Nucleare (INFN), Istituto Nazionale di Astrofisica (INAF), Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR), CETEMPS Center of Excellence, Ministero degli Affari Esteri (MAE); Mexico-Consejo Nacional de Ciencia y Tecnologia (CONACYT) Grant No. 167733, Universidad Nacional Autonoma de Mexico (UNAM), PAPIIT DGAPA-UNAM; The Netherlands-Ministry of Education, Culture and Science, Netherlands Organisation for Scientific Research (NWO), Dutch national e-infrastructure with the support of SURF Cooperative; Poland-Ministry of Science and Higher Education, Grant No. DIR/WK/2018/11, National Science Centre, Grants No. 2013/08/M/ST9/00322, No. 2016/23/B/ST9/01635, and No. HARMONIA 5-2013/10/M/ST9/00062, UMO-2016/22/M/ST9/00198; Portugal -Portuguese national funds and FEDER funds within Programa Operacional Factores de Competitividade through Fundacao para a Ciencia e a Tecnologia (COMPETE); Romania-Romanian Ministry of Education and Research, the Program Nucleu within MCI (PN19150201/16N/2019 and PN19060102), and project PN-III-P1-1.2-PCCDI-2017-0839/19PCCDI/2018 within PNCDI III; Slovenia-Slovenian Research Agency, Grants No. P1-0031, No. P1-0385, No. I00033, No. N1-0111; Spain-Ministerio de Economia, Industria y Competitividad (FPA2017-85114-P and FPA2017-85197-P), Xunta de Galicia (ED431C 2017/07), Junta de Andalucia (SOMM17/6104/UGR), Feder Funds, RENATA Red Nacional Tematica de Astroparticulas (FPA2015-68783-REDT), and Maria de Maeztu Unit of Excellence (MDM-2016-0692); U.S.Department of Energy, Awards No. DE-AC0207CH11359, No. DE-FR02-04ER41300, No. DE-FG0299ER41107, and No. DE-SC0011689, National Science Foundation, Grant No. 0450696, The Grainger Foundation, Marie Curie-IRSES/EPLANET, European Particle Physics Latin American Network, and UNESCO.We present the first measurement of the fluctuations in the number of muons in extensive air showers produced by ultrahigh energy cosmic rays. We find that the measured fluctuations are in good agreement with predictions from air shower simulations. This observation provides new insights into the origin of the previously reported deficit of muons in air shower simulations and constrains models of hadronic interactions at ultrahigh energies. Our measurement is compatible with the muon deficit originating from small deviations in the predictions from hadronic interaction models of particle production that accumulate as the showers develop.Argentina-Comision Nacional de Energia AtomicaANPCyTConsejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET)Gobierno de la Provincia de MendozaMunicipalidad de MalargueNDM HoldingsValle Las LenasAustralian Research CouncilConselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ)Fundacao de Apoio a Pesquisa do Distrito Federal (FAPDF)Financiadora de Inovacao e Pesquisa (Finep)Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio De Janeiro (FAPERJ)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) 2019/10151-2 2010/07359-6 1999/05404-3Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes (MCTIC)Ministry of Education, Youth & Sports - Czech Republic MSMT CR LTT18004 LM2015038 LM2018102 CZ.02.1.01/0.0/0.0/16_013/0001402 CZ.02.1.01/0.0/0.0/18_046/0016010 CZ.02.1.01/0.0/0.0/17_049/0008422France-Centre de Calcul IN2P3/CNRSCentre National de la Recherche Scientifique (CNRS)Region Ile-de-FranceCentre National de la Recherche Scientifique (CNRS)Departement Sciences de l'Univers (SDU-INSU/CNRS)French National Research Agency (ANR) LABEX ANR-10-LABX-63 ANR11-IDEX-0004-02Federal Ministry of Education & Research (BMBF)German Research Foundation (DFG)Finanzministerium Baden-WurttembergHelmholtz Alliance for Astroparticle Physics (HAP)Helmholtz AssociationMinisterium fur Innovation, Wissenschaft und Forschung des Landes Nordrhein-WestfalenMinisterium fur Wissenschaft, Forschung und Kunst des Landes Baden-WurttembergItaly-Istituto Nazionale di Fisica Nucleare (INFN)Istituto Nazionale Astrofisica (INAF)Ministry of Education, Universities and Research (MIUR)CETEMPS Center of ExcellenceMinistry of Foreign Affairs and International Cooperation (Italy)Consejo Nacional de Ciencia y Tecnologia (CONACyT) 167733Universidad Nacional Autonoma de Mexico (UNAM), PAPIIT DGAPA-UNAMNetherlands-Ministry of Education, Culture and ScienceNetherlands Organization for Scientific Research (NWO)Dutch national e-infrastructureSURF CooperativePoland-Ministry of Science and Higher Education DIR/WK/2018/11National Science Centre, Poland 2013/08/M/ST9/00322 2016/23/B/ST9/01635 HARMONIA 5-2013/10/M/ST9/00062 UMO-2016/22/M/ST9/00198Portugal -Portuguese national fundsFEDER funds within Programa Operacional Factores de Competitividade through Fundacao para a Ciencia e a Tecnologia (COMPETE)Romania-Romanian Ministry of Education and Research, the Program Nucleu within MCI PN19150201/16N/2019 PN19060102Romania-Romanian Ministry of Educatio n and Research, the Program Nucleu within PNCDI III PN-III-P1-1.2-PCCDI-2017-0839/19PCCDI/2018Slovenian Research Agency - Slovenia P1-0031 P1-0385 I00033 N1-0111Spain-Ministerio de Economia, Industria y Competitividad FPA2017-85114-P FPA2017-85197-PXunta de Galicia European Commission ED431C 2017/07Junta de Andalucia SOMM17/6104/UGREuropean CommissionRENATA Red Nacional Tematica de Astroparticulas FPA2015-68783-REDTMaria de Maeztu Unit of Excellence MDM-2016-0692United States Department of Energy (DOE) DE-AC0207CH11359 DE-FR02-04ER41300 DE-FG0299ER41107 DE-SC0011689National Science Foundation (NSF) 0450696Grainger FoundationMarie Curie-IRSES/EPLANETEuropean Particle Physics Latin American NetworkUNESC

Design and implementation of the AMIGA embedded system for data acquisition

International audienceThe Auger Muon Infill Ground Array (AMIGA) is part of the AugerPrime upgrade of the Pierre Auger Observatory. It consists of particle counters buried 2.3 m underground next to the water-Cherenkov stations that form the 23.5 km2 large infilled array. The reduced distance between detectors in this denser area allows the lowering of the energy threshold for primary cosmic ray reconstruction down to about 1017 eV. At the depth of 2.3 m the electromagnetic component of cosmic ray showers is almost entirely absorbed so that the buried scintillators provide an independent and direct measurement of the air showers muon content. This work describes the design and implementation of the AMIGA embedded system, which provides centralized control, data acquisition and environment monitoring to its detectors. The presented system was firstly tested in the engineering array phase ended in 2017, and lately selected as the final design to be installed in all new detectors of the production phase. The system was proven to be robust and reliable and has worked in a stable manner since its first deployment

Design, upgrade and characterization of the silicon photomultiplier front-end for the AMIGA detector at the Pierre Auger Observatory

International audienceAMIGA (Auger Muons and Infill for the Ground Array) is an upgrade of the Pierre Auger Observatory to complement the study of ultra-high-energy cosmic rays (UHECR) by measuring the muon content of extensive air showers (EAS). It consists of an array of 61 water Cherenkov detectors on a denser spacing in combination with underground scintillation detectors used for muon density measurement. Each detector is composed of three scintillation modules, with 10 m2 detection area per module, buried at 2.3 m depth, resulting in a total detection area of 30 m2. Silicon photomultiplier sensors (SiPM) measure the amount of scintillation light generated by charged particles traversing the modules. In this paper, the design of the front-end electronics to process the signals of those SiPMs and test results from the laboratory and from the Pierre Auger Observatory are described. Compared to our previous prototype, the new electronics shows a higher performance, higher efficiency and lower power consumption, and it has a new acquisition system with increased dynamic range that allows measurements closer to the shower core. The new acquisition system is based on the measurement of the total charge signal that the muonic component of the cosmic ray shower generates in the detector

Deep-learning based reconstruction of the shower maximum XmaxX_{max} using the water-Cherenkov detectors of the Pierre Auger Observatory

International audienceThe atmospheric depth of the air shower maximum X max is an observable commonly used for the determination of the nuclear mass composition of ultra-high energy cosmic rays. Direct measurements of X max are performed using observations of the longitudinal shower development with fluorescence telescopes. At the same time, several methods have been proposed for an indirect estimation of X max from the characteristics of the shower particles registered with surface detector arrays. In this paper, we present a deep neural network (DNN) for the estimation of X max. The reconstruction relies on the signals induced by shower particles in the ground based water-Cherenkov detectors of the Pierre Auger Observatory. The network architecture features recurrent long short-term memory layers to process the temporal structure of signals and hexagonal convolutions to exploit the symmetry of the surface detector array. We evaluate the performance of the network using air showers simulated with three different hadronic interaction models. Thereafter, we account for long-term detector effects and calibrate the reconstructed X max using fluorescence measurements. Finally, we show that the event-by-event resolution in the reconstruction of the shower maximum improves with increasing shower energy and reaches less than 25 g/cm2 at energies above 2 × 1019 eV

Calibration of the underground muon detector of the Pierre Auger Observatory

International audienceTo obtain direct measurements of the muon content of extensive air showers with energy above 1016.5 eV, the Pierre Auger Observatory is currently being equipped with an underground muon detector (UMD), consisting of 219 10 m2-modules, each segmented into 64 scintillators coupled to silicon photomultipliers (SiPMs). Direct access to the shower muon content allows for the study of both of the composition of primary cosmic rays and of high-energy hadronic interactions in the forward direction. As the muon density can vary between tens of muons per m2 close to the intersection of the shower axis with the ground to much less than one per m2 when far away, the necessary broad dynamic range is achieved by the simultaneous implementation of two acquisition modes in the read-out electronics: the binary mode, tuned to count single muons, and the ADC mode, suited to measure a high number of them. In this work, we present the end-to-end calibration of the muon detector modules: first, the SiPMs are calibrated by means of the binary channel, and then, the ADC channel is calibrated using atmospheric muons, detected in parallel to the shower data acquisition. The laboratory and field measurements performed to develop the implementation of the full calibration chain of both binary and ADC channels are presented and discussed. The calibration procedure is reliable to work with the high amount of channels in the UMD, which will be operated continuously, in changing environmental conditions, for several years

Ultrahigh-energy neutrino follow-up of gravitational wave events GW150914 and GW151226 with the Pierre Auger Observatory

International audienceOn September 14, 2015 the Advanced LIGO detectors observed their first gravitational-wave (GW) transient GW150914. This was followed by a second GW event observed on December 26, 2015. Both events were inferred to have arisen from the merger of black holes in binary systems. Such a system may emit neutrinos if there are magnetic fields and disk debris remaining from the formation of the two black holes. With the surface detector array of the Pierre Auger Observatory we can search for neutrinos with energy above 100 PeV from point-like sources across the sky with equatorial declination from about -65 deg. to +60 deg., and in particular from a fraction of the 90% confidence-level (CL) inferred positions in the sky of GW150914 and GW151226. A targeted search for highly-inclined extensive air showers, produced either by interactions of downward-going neutrinos of all flavors in the atmosphere or by the decays of tau leptons originating from tau-neutrino interactions in the Earth's crust (Earth-skimming neutrinos), yielded no candidates in the Auger data collected within $\pm 500$ s around or 1 day after the coordinated universal time (UTC) of GW150914 and GW151226, as well as in the same search periods relative to the UTC time of the GW candidate event LVT151012. From the non-observation we constrain the amount of energy radiated in ultrahigh-energy neutrinos from such remarkable events

Horse Population by Province, 2009-2016

We present a search for ultrarelativistic magnetic monopoles with the Pierre Auger observatory. Such particles, possibly a relic of phase transitions in the early Universe, would deposit a large amount of energy along their path through the atmosphere, comparable to that of ultrahigh-energy cosmic rays (UHECRs). The air-shower profile of a magnetic monopole can be effectively distinguished by the fluorescence detector from that of standard UHECRs. No candidate was found in the data collected between 2004 and 2012, with an expected background of less than 0.1 event from UHECRs. The corresponding 90% confidence level (C.L.) upper limits on the flux of ultrarelativistic magnetic monopoles range from 10$^{-19}$(cm$^2$ sr s)$^{−1}$ for a Lorentz factor γ=10$^9$ to 2.5×10$^{-21}$(cm$^2$ sr s)$^{−1}$ for γ=10$^{12}$. These results—the first obtained with a UHECR detector—improve previously published limits by up to an order of magnitude