A search for time-directional coincidences of ultra-high-energy (UHE) photons above 10 EeV with g... more A search for time-directional coincidences of ultra-high-energy (UHE) photons above 10 EeV with gravitational wave (GW) events from the LIGO/Virgo runs O1 to O3 is conducted with the Pierre Auger Observatory. Due to the distinctive properties of photon interactions and to the background expected from hadronic showers, a subset of the most interesting GW events is selected based on their localization quality and distance. Time periods of 1000 s around and 1 day after the GW events are analyzed. No coincidences are observed. Upper limits on the UHE photon fluence from a GW event are derived that are typically at ∼7 MeV cm−2 (time period 1000 s) and ∼35 MeV cm−2 (time period 1 day). Due to the proximity of the binary neutron star merger GW170817, the energy of the source transferred into UHE photons above 40 EeV is constrained to be less than 20% of its total GW energy. These are the first limits on UHE photons from GW sources.
We report a measurement of the proton-air cross-section for particle production at the center-ofm... more We report a measurement of the proton-air cross-section for particle production at the center-ofmass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analysing the tail of the distribution of the shower maxima, a proton-air cross-section of 505 ± 22(stat) +28 −36 (sys) mb is found.
The combined fit of the measured energy spectrum and shower maximum depth distributions of ultra-... more The combined fit of the measured energy spectrum and shower maximum depth distributions of ultra-high-energy cosmic rays is known to constrain the parameters of astrophysical models with homogeneous source distributions. Studies of the distribution of the cosmic-ray arrival directions show a better agreement with models in which a fraction of the flux is non-isotropic and associated with the nearby radio galaxy Centaurus A or with catalogs such as that of starburst galaxies. Here, we present a novel combination of both analyses by a simultaneous fit of arrival directions, energy spectrum, and composition data measured at the Pierre Auger Observatory. The model takes into account a rigidity-dependent magnetic field blurring and an energy-dependent evolution of the catalog contribution shaped by interactions during propagation. We find that a model containing a flux contribution from the starburst galaxy catalog of around 20% at 40 EeV with a magnetic field blurring of around 20 • for a rigidity of 10 EV provides a fair simultaneous description of all three observables. The starburst galaxy model is favored with a significance of 4.5σ (considering experimental systematic effects) compared to a reference model with only homogeneously distributed background sources. By investigating a scenario with Centaurus A as a single source in combination with the homogeneous background, we confirm that this region of the sky provides the dominant contribution to the observed anisotropy signal. Models containing a catalog of jetted active galactic nuclei whose flux scales with the γ-ray emission are, however, disfavored as they cannot adequately describe the measured arrival directions.
The Pierre Auger Observatory, at present the largest cosmic-ray observatory ever built, is instru... more The Pierre Auger Observatory, at present the largest cosmic-ray observatory ever built, is instrumented with a ground array of 1600 water-Cherenkov detectors, known as the Surface Detector (SD). The SD samples the secondary particle content (mostly photons, electrons, positrons and muons) of extensive air showers initiated by cosmic rays with energies ranging from 1017eV up to more than 1020eV. Measuring the independent contribution of the muon component to the total registered signal is crucial to enhance the capability of the Observatory to estimate the mass of the cosmic rays on an event-by-event basis. However, with the current design of the SD, it is difficult to straightforwardly separate the contributions of muons to the SD time traces from those of photons, electrons and positrons. In this paper, we present a method aimed at extracting the muon component of the time traces registered with each individual detector of the SD using Recurrent Neural Networks. We derive the performances of the method by training the neural network on simulations, in which the muon and the electromagnetic components of the traces are known. We conclude this work showing the performance of this method on experimental data of the Pierre Auger Observatory. We find that our predictions agree with the parameterizations obtained by the AGASA collaboration to describe the lateral distributions of the electromagnetic and muonic components of extensive air showers.
The Surface Array of the Pierre Auger Observatory consists of 1660 water Cherenkov detectors that... more The Surface Array of the Pierre Auger Observatory consists of 1660 water Cherenkov detectors that sample at the ground the charged particles and photons of air showers initiated by energetic cosmic rays. The construction of the array in Malargüe, Argentina is now complete. A large fraction of the detectors have been operational for more than five years. Each detector records data locally with timing obtained from GPS units and power from solar panels and batteries. In this paper, the performance and the operation of the array are discussed. We emphasise the accuracy of the signal measurement, the stability of the triggering, the performance of the solar power system and other hardware, and the long-term purity of the water.
Nuclear Instruments and Methods in Physics Research, Apr 1, 2011
The advent of the Auger Engineering Radio Array (AERA) necessitates the development of a powerful... more The advent of the Auger Engineering Radio Array (AERA) necessitates the development of a powerful framework for the analysis of radio measurements of cosmic ray air showers. As AERA performs "radio-hybrid" measurements of air shower radio emission in coincidence with the surface particle detectors and fluorescence telescopes of the Pierre Auger Observatory, the radio analysis functionality had to be incorporated in the existing hybrid analysis solutions for fluoresence and surface detector data. This goal has been achieved in a natural way by extending the existing Auger Offline software framework with radio functionality. In this article, we lay out the design, highlights and features of the radio extension implemented in the Auger Offline framework. Its functionality has achieved a high degree of sophistication and offers advanced features such as vectorial reconstruction of the electric field, advanced signal processing algorithms, a transparent and efficient handling of FFTs, a very detailed simulation of detector effects, and the read-in of multiple data formats including data from various radio simulation codes. The source code of this radio functionality can be made available to interested parties on request.
The Pierre Auger Observatory, located in Argentina, provides an unprecedented integrated aperture... more The Pierre Auger Observatory, located in Argentina, provides an unprecedented integrated aperture for the search of photons with energy above 100 PeV. In this contribution recent results are presented including the diffuse search for photons and the directional search for photon point sources. The derived limits are of considerable astrophysical interest: Diffuse limits place severe constraints on top-down models and start to touch the predicted GZK photon flux range while directional limits can exclude the continuation of the electromagnetic flux from measured TeV sources with a significance of more than 5σ. Finally, prospects of neutral particle searches for the upcoming detector upgrade AugerPrime are highlighted.
The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowi... more The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current in...
Ultra-high-energy photons with energies exceeding 1017 eV offer a wealth of connections to differ... more Ultra-high-energy photons with energies exceeding 1017 eV offer a wealth of connections to different aspects of cosmic-ray astrophysics as well as to gamma-ray and neutrino astronomy. The recent observations of photons with energies in the 1015 eV range further motivate searches for even higher-energy photons. In this paper, we present a search for photons with energies exceeding 2 × 1017 eV using about 5.5 yr of hybrid data from the low-energy extensions of the Pierre Auger Observatory. The upper limits on the integral photon flux derived here are the most stringent ones to date in the energy region between 1017 and 1018 eV.
The Deep Underground Neutrino Experiment (DUNE) is a leading-edge experiment for long-baseline ne... more The Deep Underground Neutrino Experiment (DUNE) is a leading-edge experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE-Dual Phase (DP) is a 6 × 6 × 6 m3 liquid argon time-projection-chamber (LArTPC) operated at the CERN Neutrino Platform in 2019–2020 as a prototype of the DUNE far detector. In ProtoDUNE-DP, the scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, we present the performance of the ProtoDUNE-DP photon detection system, comparing different wavelength-shifting techniques and the use of xenon-doped LAr as a promising option for future large LArTPCs. The scintillation light production and propagation processes are analyzed and compared to simulations, improving understanding of the liquid argon properties.
Journal of Cosmology and Astroparticle Physics, 2021
The observation of 236 MeV muon neutrinos from kaon-decay-at-rest (KDAR) originating in the core ... more The observation of 236 MeV muon neutrinos from kaon-decay-at-rest (KDAR) originating in the core of the Sun would provide a unique signature of dark matter annihilation. Since excellent angle and energy reconstruction are necessary to detect this monoenergetic, directional neutrino flux, DUNE with its vast volume and reconstruction capabilities, is a promising candidate for a KDAR neutrino search. In this work, we evaluate the proposed KDAR neutrino search strategies by realistically modeling both neutrino-nucleus interactions and the response of DUNE. We find that, although reconstruction of the neutrino energy and direction is difficult with current techniques in the relevant energy range, the superb energy resolution, angular resolution, and particle identification offered by DUNE can still permit great signal/background discrimination. Moreover, there are non-standard scenarios in which searches at DUNE for KDAR in the Sun can probe dark matter interactions.
To cite this article: B. Abi et al 2020 JINST 15 P12004 View the article online for updates and e... more To cite this article: B. Abi et al 2020 JINST 15 P12004 View the article online for updates and enhancements. Recent citations Spectroscopic analysis of the gaseous argon scintillation with a wavelength sensitive particle detector R. Santorelli et al-Development of very-thick transparent GEMs with wavelength-shifting capability for noble element TPCs M. Kuniak et al
tasks to be performed are partitioned in a hierarchical manner. 71, 130, 220, 224 warm interface ... more tasks to be performed are partitioned in a hierarchical manner. 71, 130, 220, 224 warm interface board (WIB) Digital electronics situated just outside the SP cryostat that receives digital data from the FEMBs over cold copper connections and sends it to the RCE FE readout hardware. 133, 160, 161 wavelength shifting (WLS) A material or process by which incident photons are absorbed by a material and photons are emitted at a different, typically longer, wavelength. 106
Journal of Cosmology and Astroparticle Physics, 2013
To interpret the mean depth of cosmic ray air shower maximum and its dispersion, we parametrize t... more To interpret the mean depth of cosmic ray air shower maximum and its dispersion, we parametrize those two observables as functions of the first two moments of the ln A distribution. We examine the goodness of this simple method through simulations of test mass distributions. The application of the parameterization to Pierre Auger Observatory data allows one to study the energy dependence of the mean ln A and of its variance under the assumption of selected hadronic interaction models. We discuss possible implications of these dependences in term of interaction models and astrophysical cosmic ray sources.
Journal of Cosmology and Astroparticle Physics, May 9, 2013
We derive lower bounds on the density of sources of ultra-high energy cosmic rays from the lack o... more We derive lower bounds on the density of sources of ultra-high energy cosmic rays from the lack of significant clustering in the arrival directions of the highest energy events detected at the Pierre Auger Observatory. The density of uniformly distributed sources of equal intrinsic intensity was found to be larger than ∼ (0.06 − 5) × 10 −4 Mpc −3 at 95% CL, depending on the magnitude of the magnetic deflections. Similar bounds, in the range (0.2 − 7) × 10 −4 Mpc −3 , were obtained for sources following the local matter distribution.
A search for time-directional coincidences of ultra-high-energy (UHE) photons above 10 EeV with g... more A search for time-directional coincidences of ultra-high-energy (UHE) photons above 10 EeV with gravitational wave (GW) events from the LIGO/Virgo runs O1 to O3 is conducted with the Pierre Auger Observatory. Due to the distinctive properties of photon interactions and to the background expected from hadronic showers, a subset of the most interesting GW events is selected based on their localization quality and distance. Time periods of 1000 s around and 1 day after the GW events are analyzed. No coincidences are observed. Upper limits on the UHE photon fluence from a GW event are derived that are typically at ∼7 MeV cm−2 (time period 1000 s) and ∼35 MeV cm−2 (time period 1 day). Due to the proximity of the binary neutron star merger GW170817, the energy of the source transferred into UHE photons above 40 EeV is constrained to be less than 20% of its total GW energy. These are the first limits on UHE photons from GW sources.
We report a measurement of the proton-air cross-section for particle production at the center-ofm... more We report a measurement of the proton-air cross-section for particle production at the center-ofmass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analysing the tail of the distribution of the shower maxima, a proton-air cross-section of 505 ± 22(stat) +28 −36 (sys) mb is found.
The combined fit of the measured energy spectrum and shower maximum depth distributions of ultra-... more The combined fit of the measured energy spectrum and shower maximum depth distributions of ultra-high-energy cosmic rays is known to constrain the parameters of astrophysical models with homogeneous source distributions. Studies of the distribution of the cosmic-ray arrival directions show a better agreement with models in which a fraction of the flux is non-isotropic and associated with the nearby radio galaxy Centaurus A or with catalogs such as that of starburst galaxies. Here, we present a novel combination of both analyses by a simultaneous fit of arrival directions, energy spectrum, and composition data measured at the Pierre Auger Observatory. The model takes into account a rigidity-dependent magnetic field blurring and an energy-dependent evolution of the catalog contribution shaped by interactions during propagation. We find that a model containing a flux contribution from the starburst galaxy catalog of around 20% at 40 EeV with a magnetic field blurring of around 20 • for a rigidity of 10 EV provides a fair simultaneous description of all three observables. The starburst galaxy model is favored with a significance of 4.5σ (considering experimental systematic effects) compared to a reference model with only homogeneously distributed background sources. By investigating a scenario with Centaurus A as a single source in combination with the homogeneous background, we confirm that this region of the sky provides the dominant contribution to the observed anisotropy signal. Models containing a catalog of jetted active galactic nuclei whose flux scales with the γ-ray emission are, however, disfavored as they cannot adequately describe the measured arrival directions.
The Pierre Auger Observatory, at present the largest cosmic-ray observatory ever built, is instru... more The Pierre Auger Observatory, at present the largest cosmic-ray observatory ever built, is instrumented with a ground array of 1600 water-Cherenkov detectors, known as the Surface Detector (SD). The SD samples the secondary particle content (mostly photons, electrons, positrons and muons) of extensive air showers initiated by cosmic rays with energies ranging from 1017eV up to more than 1020eV. Measuring the independent contribution of the muon component to the total registered signal is crucial to enhance the capability of the Observatory to estimate the mass of the cosmic rays on an event-by-event basis. However, with the current design of the SD, it is difficult to straightforwardly separate the contributions of muons to the SD time traces from those of photons, electrons and positrons. In this paper, we present a method aimed at extracting the muon component of the time traces registered with each individual detector of the SD using Recurrent Neural Networks. We derive the performances of the method by training the neural network on simulations, in which the muon and the electromagnetic components of the traces are known. We conclude this work showing the performance of this method on experimental data of the Pierre Auger Observatory. We find that our predictions agree with the parameterizations obtained by the AGASA collaboration to describe the lateral distributions of the electromagnetic and muonic components of extensive air showers.
The Surface Array of the Pierre Auger Observatory consists of 1660 water Cherenkov detectors that... more The Surface Array of the Pierre Auger Observatory consists of 1660 water Cherenkov detectors that sample at the ground the charged particles and photons of air showers initiated by energetic cosmic rays. The construction of the array in Malargüe, Argentina is now complete. A large fraction of the detectors have been operational for more than five years. Each detector records data locally with timing obtained from GPS units and power from solar panels and batteries. In this paper, the performance and the operation of the array are discussed. We emphasise the accuracy of the signal measurement, the stability of the triggering, the performance of the solar power system and other hardware, and the long-term purity of the water.
Nuclear Instruments and Methods in Physics Research, Apr 1, 2011
The advent of the Auger Engineering Radio Array (AERA) necessitates the development of a powerful... more The advent of the Auger Engineering Radio Array (AERA) necessitates the development of a powerful framework for the analysis of radio measurements of cosmic ray air showers. As AERA performs "radio-hybrid" measurements of air shower radio emission in coincidence with the surface particle detectors and fluorescence telescopes of the Pierre Auger Observatory, the radio analysis functionality had to be incorporated in the existing hybrid analysis solutions for fluoresence and surface detector data. This goal has been achieved in a natural way by extending the existing Auger Offline software framework with radio functionality. In this article, we lay out the design, highlights and features of the radio extension implemented in the Auger Offline framework. Its functionality has achieved a high degree of sophistication and offers advanced features such as vectorial reconstruction of the electric field, advanced signal processing algorithms, a transparent and efficient handling of FFTs, a very detailed simulation of detector effects, and the read-in of multiple data formats including data from various radio simulation codes. The source code of this radio functionality can be made available to interested parties on request.
The Pierre Auger Observatory, located in Argentina, provides an unprecedented integrated aperture... more The Pierre Auger Observatory, located in Argentina, provides an unprecedented integrated aperture for the search of photons with energy above 100 PeV. In this contribution recent results are presented including the diffuse search for photons and the directional search for photon point sources. The derived limits are of considerable astrophysical interest: Diffuse limits place severe constraints on top-down models and start to touch the predicted GZK photon flux range while directional limits can exclude the continuation of the electromagnetic flux from measured TeV sources with a significance of more than 5σ. Finally, prospects of neutral particle searches for the upcoming detector upgrade AugerPrime are highlighted.
The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowi... more The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current in...
Ultra-high-energy photons with energies exceeding 1017 eV offer a wealth of connections to differ... more Ultra-high-energy photons with energies exceeding 1017 eV offer a wealth of connections to different aspects of cosmic-ray astrophysics as well as to gamma-ray and neutrino astronomy. The recent observations of photons with energies in the 1015 eV range further motivate searches for even higher-energy photons. In this paper, we present a search for photons with energies exceeding 2 × 1017 eV using about 5.5 yr of hybrid data from the low-energy extensions of the Pierre Auger Observatory. The upper limits on the integral photon flux derived here are the most stringent ones to date in the energy region between 1017 and 1018 eV.
The Deep Underground Neutrino Experiment (DUNE) is a leading-edge experiment for long-baseline ne... more The Deep Underground Neutrino Experiment (DUNE) is a leading-edge experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE-Dual Phase (DP) is a 6 × 6 × 6 m3 liquid argon time-projection-chamber (LArTPC) operated at the CERN Neutrino Platform in 2019–2020 as a prototype of the DUNE far detector. In ProtoDUNE-DP, the scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, we present the performance of the ProtoDUNE-DP photon detection system, comparing different wavelength-shifting techniques and the use of xenon-doped LAr as a promising option for future large LArTPCs. The scintillation light production and propagation processes are analyzed and compared to simulations, improving understanding of the liquid argon properties.
Journal of Cosmology and Astroparticle Physics, 2021
The observation of 236 MeV muon neutrinos from kaon-decay-at-rest (KDAR) originating in the core ... more The observation of 236 MeV muon neutrinos from kaon-decay-at-rest (KDAR) originating in the core of the Sun would provide a unique signature of dark matter annihilation. Since excellent angle and energy reconstruction are necessary to detect this monoenergetic, directional neutrino flux, DUNE with its vast volume and reconstruction capabilities, is a promising candidate for a KDAR neutrino search. In this work, we evaluate the proposed KDAR neutrino search strategies by realistically modeling both neutrino-nucleus interactions and the response of DUNE. We find that, although reconstruction of the neutrino energy and direction is difficult with current techniques in the relevant energy range, the superb energy resolution, angular resolution, and particle identification offered by DUNE can still permit great signal/background discrimination. Moreover, there are non-standard scenarios in which searches at DUNE for KDAR in the Sun can probe dark matter interactions.
To cite this article: B. Abi et al 2020 JINST 15 P12004 View the article online for updates and e... more To cite this article: B. Abi et al 2020 JINST 15 P12004 View the article online for updates and enhancements. Recent citations Spectroscopic analysis of the gaseous argon scintillation with a wavelength sensitive particle detector R. Santorelli et al-Development of very-thick transparent GEMs with wavelength-shifting capability for noble element TPCs M. Kuniak et al
tasks to be performed are partitioned in a hierarchical manner. 71, 130, 220, 224 warm interface ... more tasks to be performed are partitioned in a hierarchical manner. 71, 130, 220, 224 warm interface board (WIB) Digital electronics situated just outside the SP cryostat that receives digital data from the FEMBs over cold copper connections and sends it to the RCE FE readout hardware. 133, 160, 161 wavelength shifting (WLS) A material or process by which incident photons are absorbed by a material and photons are emitted at a different, typically longer, wavelength. 106
Journal of Cosmology and Astroparticle Physics, 2013
To interpret the mean depth of cosmic ray air shower maximum and its dispersion, we parametrize t... more To interpret the mean depth of cosmic ray air shower maximum and its dispersion, we parametrize those two observables as functions of the first two moments of the ln A distribution. We examine the goodness of this simple method through simulations of test mass distributions. The application of the parameterization to Pierre Auger Observatory data allows one to study the energy dependence of the mean ln A and of its variance under the assumption of selected hadronic interaction models. We discuss possible implications of these dependences in term of interaction models and astrophysical cosmic ray sources.
Journal of Cosmology and Astroparticle Physics, May 9, 2013
We derive lower bounds on the density of sources of ultra-high energy cosmic rays from the lack o... more We derive lower bounds on the density of sources of ultra-high energy cosmic rays from the lack of significant clustering in the arrival directions of the highest energy events detected at the Pierre Auger Observatory. The density of uniformly distributed sources of equal intrinsic intensity was found to be larger than ∼ (0.06 − 5) × 10 −4 Mpc −3 at 95% CL, depending on the magnitude of the magnetic deflections. Similar bounds, in the range (0.2 − 7) × 10 −4 Mpc −3 , were obtained for sources following the local matter distribution.
The Pierre Auger Observatory is the world's largest detector ever built for detecting and studyin... more The Pierre Auger Observatory is the world's largest detector ever built for detecting and studying the ultra-high energy cosmic rays, the most energetic particles in the Universe. It is an international effort of more than one hundred institutions from 18 countries which has been taken data for more than twelve years. The observatory in Argentina consists of a hybrid detector of 1660 water Cherenkov stations covering an area of 3,000 km^2 overlooked by 27 fluorescence telescopes and arrays of radio antennas. Since 2008, it has been completed reaching an unprecedented exposure of 50,000 km^2·sr·yr. Its objectives are to probe the origin, characteristics and to study the interactions of cosmic rays with energies above 10^17 eV. Important results have been published by the collaboration in the last years about the energy spectrum, the primary mass composition, the searches for primary photons and neutrinos and studies of the anisotropy of arrival directions, among others. In this work, we report the main recent results and discuss briefly the future plans for the observatory upgrades.
Raios cósmicos são núcleos atômicos, de prótons a elementos
mais pesados, que viajam pelo espaço ... more Raios cósmicos são núcleos atômicos, de prótons a elementos mais pesados, que viajam pelo espaço quase à velocidade da luz, transportando energias extremamente altas. Nesta pesquisa, os autores desenvolveram uma simulação da propagação de raios cósmicos em campos magnéticos astrofísicos.
We present a novel numerical model for the propagation of ultra-high energy cosmic rays in the ex... more We present a novel numerical model for the propagation of ultra-high energy cosmic rays in the extragalactic medium. We take into account the diffusion of ultrarelativistic charged particles under the influence of the magnetic fields, and their energy losses. The magnetic fields are considered to be coherent within spheric cells, and with smooth transitions between them. The propagator presents a very high accuracy on calculating the particle tracking, on the order of 10 −33 of relative error in energy, and 10 −5 in Larmor radius.
We present the design, and preliminary results of the LIDRAE water-Cherenkov air shower array ins... more We present the design, and preliminary results of the LIDRAE water-Cherenkov air shower array installed at UFABC (23.6 • S, 46.5 • W, 750 m a.s.l.). LIDRAE detects the particles of extensive air showers with energies exceeding 100 TeV and is able to measure the arrival direction and energy of the primary cosmic rays. The array is composed of three tanks each filled with one thousand liters of water with a large aperture photomultiplier on the top cover of each tank overlooking the water volume. The photomultipliers detect the Cherenkov light generated by the passage of ultrarelativistic charged particles through the water. The produced signals are then sent to the data acquisition electronics where they are amplified, formatted, digitized and stored. The data are recorded in single and triple coincidence modes.
The Pierre Auger Observatory is the world's largest detector ever built for detecting and studyin... more The Pierre Auger Observatory is the world's largest detector ever built for detecting and studying the ultra-high energy cosmic rays, the most energetic particles in the Universe. It is an international effort of more than one hundred institutions from 18 countries which has been taken data for more than twelve years. The observatory in Argentina consists of a hybrid detector of 1660 water Cherenkov stations-covering an area of 3, 000 km 2-overlooked by 27 fluorescence telescopes and arrays of radio antennas. Since 2008, it has been completed reaching an unprecedented exposure of 50, 000 km 2 · sr · yr. Its objectives are to probe the origin, characteristics and to study the interactions of cosmic rays with energies above 10 17 eV. Important results have been published by the collaboration in the last years about the energy spectrum, the primary mass composition, the searches for primary photons and neutrinos and studies of the anisotropy of arrival directions, among others. In this work, we report the main recent results and discuss briefly the future plans for the observatory upgrades.
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Papers by Marcelo Leigui
mais pesados, que viajam pelo espaço quase à velocidade da luz,
transportando energias extremamente altas. Nesta pesquisa, os autores
desenvolveram uma simulação da propagação de raios cósmicos em
campos magnéticos astrofísicos.