Design and implementation of the AMIGA embedded system for data acquisition

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 admin-istrative staff in Malargtie. We are very grateful to the following agencies and organizations for financial support: Comision Nacional de Energla Atomica, Agencia Nacional de Promocion Cientffica y Tec-nologica (ANPCyT) , Consejo Nacional de Investigaciones Cientfficas y Tecnicas (CONICET) , Gobierno de la Provincia de Mendoza, Municipalidad de Malargtie, NDM Holdings and Valle Las Leilas, in gratitude for their continuing cooperation over land access, Argentina; the Australian Research Council; Conselho Nacional de Desenvolvimento Cientffico e Tecnologico (CNPq) , Fi-nanciadora de Estudos e Projetos (FINEP) , FundagAo de Amparo a Pesquisa do Estado de Rio de Janeiro (FAPERJ) , SAo Paulo Research Foundation (FAPESP) Grants No. 2010/07359-6 and No. 1999/05404-3, Ministerio de Ciencia e Tecnologia (MCT) , Brazil; Grant No.MSMT CR LG15014, LO1305 and LM2015038 and the Czech Science Foundation Grant No. 14-17501S, Czech Republic; Centre de Calcul IN2P3/CNRS, Centre National de la Recherche Scientifique (CNRS) , Conseil Regional Ile-de-France, Departement Physique Nucleaire 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. ANR-11-IDEX-0004-02, France; Bundesministerium fur Bildung und Forschung (BMBF) , Deutsche Forschungsgemeinschaft (DFG) , Finanzministerium Baden-Wurttemberg, Helmholtz Al-liance for Astroparticle Physics (HAP) , Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF) , Ministerium fur Wissenschaft und Forschung, Nordrhein Westfalen, Ministerium fur Wis-senschaft, Forschung und Kunst, Baden-Wurttemberg, Germany; Istituto Nazionale di Fisica Nu-cleare (INFN) ,Istituto Nazionale di Astrofisica (INAF) , Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR) , Gran Sasso Center for Astroparticle Physics (CFA) , CETEMPS Cen-ter of Excellence, Ministero degli Affari Esteri (MAE) , Italy; Consejo Nacional de Ciencia y Tecnologia (CONACYT) No. 167733, Mexico; Universidad Nacional Autonoma de Mexico (UNAM) , PAPIIT DGAPA-UNAM, Mexico; Ministerie van Onderwijs, Cultuur en Wetenschap, Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO) , Stichting voor Fundamenteel Onderzoek der Materie (FOM) , Netherlands; National Centre for Research and Development, Grants No. ERA-NET-ASPERA/01/11 and No. ERA-NET-ASPERA/02/11, National Science Cen-tre, Grants No. 2013/08/M/ST9/00322, No. 2013/08/M/ST9/00728 and No. HARMONIA 5 - 2013/10/M/ST9/00062, Poland; Portuguese national funds and FEDER funds within Programa Operacional Factores de Competitividade through Fundagdo para a Ciencia e a Tecnologia (COM-PETE) , Portugal; Romanian Authority for Scientific Research ANCS, CNDI-UEFISCDI partner-ship projects Grants No. 20/2012 and No.194/2012 and PN 16 42 01 02; Slovenian Research Agency, Slovenia; Comunidad de Madrid, Fondo Europeo de Desarrollo Regional (FEDER) funds, Ministerio de Economia y Competitividad, Xunta de Galicia, European Community 7th Frame-work Program, Grant No. FP7-PEOPLE-2012-IEF-328826, Spain; Science and Technology Fa-cilities Council, United Kingdom; Department of Energy, Contracts No. DE-AC02-07CH11359, No. DE-FR02-04ER41300, No. DE-FG02-99ER41107 and No. DE-SC0011689, National Science Foundation, Grant No. 0450696, The Grainger Foundation, U.S.A. ; NAFOSTED, Vietnam; Marie Curie-IRSES/EPLANET, European Particle Physics Latin American Network, European Union 7th Framework Program, Grant No. PIRSES-2009-GA-246806; and UNESCO.The Auger Muon Infill Ground Array (AMIGA) is part of the AugerPrime upgrade of the Pierre Auger Observatory. It consists of particle counters buried 2.3m 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 2.3m 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.Comision Nacional de Energla AtomicaANPCyTConsejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET)Gobierno de la Provincia de MendozaMunicipalidad de MalargtieNDM HoldingsAustralian Research CouncilConselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ)Financiadora de Inovacao e Pesquisa (Finep)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) 2010/07359-6 1999/05404-3Ministerio de Ciencia e Tecnologia (MCT) , BrazilGrant Agency of the Czech Republic Czech Republic Government 14-17501SCentre de Calcul IN2P3/CNRSCentre National de la Recherche Scientifique (CNRS) Region Ile-de-France Departement Physique Nucleaire et Corpusculaire PNC-IN2P3/CNRS Departement Sciences de l'Univers (SDU-INSU/CNRS) French National Research Agency (ANR) LABEX ANR-10-LABX-63 ANR-11-IDEX-0004-02Federal Ministry of Education & Research (BMBF)German Research Foundation (DFG) Finanzministerium Baden-Wurttemberg, Helmholtz Al-liance for Astroparticle Physics (HAP) Helmholtz Association Ministerium fur Wissenschaft und Forschung, Nordrhein Westfalen Ministerium fur Wis-senschaft, Forschung und Kunst, Baden-Wurttemberg, GermanyIstituto Nazionale di Fisica Nucleare (INFN) Istituto Nazionale Astrofisica (INAF)Ministry of Education, Universities and Research (MIUR)Gran Sasso Center for Astroparticle Physics (CFA)CETEMPS Cen-ter of ExcellenceMinistry of Foreign Affairs and International Cooperation (Italy)Consejo Nacional de Ciencia y Tecnologia (CONACyT) 167733Mexico; Universidad Nacional Autonoma de Mexico (UNAM)Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica (PAPIIT)Universidad Nacional Autonoma de MexicoMinisterie van Onderwijs, Cultuur en Wetenschap Netherlands Organization for Scientific Research (NWO) FOM (The Netherlands) Netherlands GovernmentNational Centre for Research & Development, Poland ERA-NET-ASPERA/01/11 ERA-NET-ASPERA/02/11National Science Centre, Poland 2013/08/M/ST9/00322 2013/08/M/ST9/00728 HARMONIA 5 - 2013/10/M/ST9/00062Portuguese national fundsFEDER funds within Programa Operacional Factores de Competitividade through Fundagdo para a Ciencia e a Tecnologia (COM-PETE) , PortugalRomanian Authority for Scientific Research ANCSConsiliul National al Cercetarii Stiintifice (CNCS) Unitatea Executiva pentru Finantarea Invatamantului Superior, a Cercetarii, Dezvoltarii si Inovarii (UEFISCDI) 20/2012 194/2012 PN 16 42 01 02Slovenian Research Agency - SloveniaComunidad de MadridFondo Europeo de Desarrollo Regional (FEDER) funds, Ministerio de Economia y Competitividad,Xunta de Galicia ,European Community 7th Frame-work Program FP7-PEOPLE-2012-IEF-328826UK Research & Innovation (UKRI)Science & Technology Facilities Council (STFC)United States Department of Energy (DOE) DE-FG02-99ER41107 DE-SC0011689National Science Foundation (NSF) 0450696Grainger Foundation, U.S.ANational Foundation for Science & Technology Development (NAFOSTED)Marie Curie-IRSES/EPLANETEuropean Particle Physics Latin American Network European Commission PIRSES-2009-GA-246806UNESCOMSMT CR LG15014 LO1305 LM201503

Design, upgrade and characterization of the silicon photomultiplier front-end for the AMIGA detector at 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; Brazil -Conselho 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); Czech Republic Grant No. 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 and 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 Nucleaire 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. ANR-11-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) 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 P1-0031, P1-0385, I0-0033, 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.A. -Department of Energy, Contracts No. DE-AC02-07CH11359, No. DE-FR02-04ER41300, No. DE-FG02-99ER41107 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.AMIGA (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 m(2) detection area per module, buried at 2.3 m depth, resulting in a total detection area of 30 m(2). 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.Argentina - Comision Nacional de Energia AtomicaArgentina - Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT)Argentina - Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET)Argentina - Gobierno de la Provincia de MendozaArgentina - Municipalidad de MalargueArgentina - NDM HoldingsArgentina - Valle Las LenasAustralian Research CouncilConselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) Fundacao de Apoio a Pesquisa do Distrito Federal (FAPDF) Brazil - Financiadora de Estudos e Projetos (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 1999/05404-3Brazil - Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes (MCTIC)Brazil - Czech Republic Grant 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)France - Conseil Regional Ile-de-FranceFrance - Departement Physique Nucleaire et Corpusculaire (PNC-IN2P3/CNRS)France - Departement Sciences de l'Univers (SDU-INSU/CNRS)French National Research Agency (ANR) LABEX ANR-10-LABX-63Institut Lagrange de Paris (ILP) within the Investissements d'Avenir Programme ANR-11-IDEX-0004-02Federal Ministry of Education & Research (BMBF)Bundesministerium fur Bildung und Forschung (BMBF)German Research Foundation (DFG)Germany - Finanzministerium Baden-WurttembergGermany - Helmholtz Alliance for Astroparticle Physics (HAP)Germany - Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF)Germany - Ministerium fur Innovation, Wissenschaft und Forschung des Landes Nordrhein-WestfalenGermany - Ministerium fur Wissenschaft, Forschung und Kunst des Landes Baden-WurttembergItaly - Istituto Nazionale di Fisica Nucleare (INFN)Italy - Istituto Nazionale di Astrofisica (INAF)Italy - Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR)Italy - CETEMPS Center of ExcellenceConsejo Nacional de Ciencia y Tecnologia (CONACyT) 167733Mexico - Universidad Nacional Autonoma de Mexico (UNAM)Mexico - PAPIIT DGAPA-UNAMNetherlands - Ministry of Education, Culture and ScienceNetherlands Organization for Scientific Research (NWO)Netherlands Organisation for Scientific Research (NWO)The Netherlands - SURF CooperativePoland - Ministry of Science and Higher Education DIR/WK/2018/11 Poland - National Science Centre 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 funds Portugal - FEDER funds within Programa Operacional Factores de Competitividade through Fundacao para a Ciencia e a Tecnologia (COMPETE)Romania - Romanian Ministry of Education and Research Romania - Program Nucleu within MCI PN19150201/16N/2019 PN19060102 Romania - PNCDI III PN-III-P1-1.2-PCCDI-2017-0839/19PCCDI/2018Slovenian Research Agency - Slovenia P1-0031 P1-0385 I0-0033 N1-0111Spain - Ministerio de Economia, Industria y Competitividad FPA2017-85114-P FPA2017-85197-PSpain - Xunta de Galicia ED431C 2017/07Junta de Andalucia SOMM17/6104/UGRSpain - Feder FundsSpain - RENATA Red Nacional Tematica de Astroparticulas FPA2015-68783-REDTSpain - Maria de Maeztu Unit of Excellence MDM-2016-0692United States Department of Energy (DOE) DE-AC02-07CH11359National Science Foundation (NSF) 0450696U.S.A. - Grainger Foundation U.S.A. - Marie Curie-IRSES/EPLANET U.S.A. - European Particle Physics Latin American Network U.S.A. - UNESCOItaly - Ministero degli Affari Esteri (MAE)The Netherlands - Dutch national e-infrastructur

Deep-learning based reconstruction of the shower maximum Xmax using the water-Cherenkov detectors of 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; Brazil - Conselho 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); Czech Republic Grant No. 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 and 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 Nucleaire 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. ANR-11-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) 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 PN-19060102) and project PNIII-P1-1.2-PCCDI-2017-0839/19PCCDI/2018 within PNCDI III; Slovenia - Slovenian Research Agency, grants P1-0031, P1-0385, I0-0033, N1-0111; Spain - Ministerio de Economia, Industria y Competitividad (FPA2017-85114-P and PID2019-104676GB-C32, Xunta de Galicia (ED431C 2017/07), Junta de Andalucia (SOMM17/6104/UGR, P18-FR-4314) Feder Funds, RENATA Red Nacional Tematica de Astroparticulas (FPA2015-68783-REDT) and Maria de Maeztu Unit of Excellence (MDM-2016-0692); USA -Department of Energy, Contracts No. DE-AC02-07CH11359, No. DE-FR02-04ER41300, No. DE-FG02-99ER41107 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.The 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/cm(2) at energies above 2x10(19) eV.United States Department of Energy (DOE) DE-AC02-07CH11359 - DE-FR02-04ER41300 - DE- FG02-99ER41107 - DE-SC0011689Argentina - Comision Nacional de Energia AtomicaArgentina - Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT)Argentina - Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET)Argentina - Gobierno de la Provincia de MendozaArgentina - Municipalidad de MalargueAustralian Research CouncilConselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) Fundacao de Apoio a Pesquisa do Distrito Federal (FAPDF)Brazil - Financiadora de Estudos e Projetos (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) 2019/10151-2-2010/07359-6-1999/05404-3Brazil - Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes (MCTIC)Czech Republic Grant 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)France - Conseil Regional Ile-de-FranceFrance - Departement Physique Nucleaire et Corpusculaire (PNC-IN2P3/CNRS)France - Departement Sciences de l'Univers (SDU-INSU/CNRS)French National Research Agency (ANR) LABEX ANR-10-LABX-63 - ANR-11-IDEX-0004-02Federal Ministry of Education & Research (BMBF)German Research Foundation (DFG)Germany-Finanzministerium Baden-WurttembergGermany-Helmholtz Alliance for Astroparticle Physics (HAP)Germany-Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF)Germany-Ministerium fur Innovation, Wissenschaft und Forschung des Landes Nordrhein-WestfalenGermany-Ministerium fur Wissenschaft, Forschung und Kunst des Landes Baden-WurttembergItaly - Istituto Nazionale di Fisica Nucleare (INFN)Italy - Istituto Nazionale di Astrofisica (INAF)Italy - Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR)Italy - CETEMPS Center of ExcellenceItaly - Ministero degli Affari Esteri (MAE)Consejo Nacional de Ciencia y Tecnologia (CONACyT) 167733Mexico-Universidad Nacional Autonoma de Mexico (UNAM)Mexico-PAPIIT DGAPA-UNAMThe Netherlands - Ministry of Education, Culture and ScienceNetherlands Organization for Scientific Research (NWO)The Netherlands - SURF CooperativePoland - Ministry of Science and Higher Education DIR/WK/2018/11Poland - National Science Centre 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 fundsPortugal - FEDER funds within Programa Operacional Factores de Competitividade through Fundacao para a Ciencia e a Tecnologia (COMPETE)Romania-Romanian Ministry of Education and ResearchRomania-Program Nucleu within MCI PN19150201/16N/2019 - PN-19060102Romania-PNCDI III PNIII-P1-1.2-PCCDI-2017-0839/19PCCDI/2018Slovenian Research Agency - Slovenia P1-0031 - P1-0385 - I0-0033 - N1-0111Spain - Ministerio de Economia, Industria y Competitividad FPA2017-85114-P - PID2019-104676GB-C32Spain - Xunta de Galicia ED431C 2017/07Junta de Andalucia SOMM17/6104/UGR - P18-FR-4314Spain - RENATA Red Nacional Tematica de Astroparticulas FPA2015-68783-REDTSpain - Maria de Maeztu Unit of Excellence MDM-2016-0692National Science Foundation (NSF) 0450696USA - Grainger FoundationUSA - Marie Curie-IRSES/EPLANETUSA - European Particle Physics Latin American NetworkUSA - UNESCOArgentina - NDM Holdings and Valle Las LenasThe Netherlands - Dutch national e-infrastructureSpain - Feder Fund

Composition Classification of Ultra-High Energy Cosmic Rays

The study of cosmic rays remains as one of the most challenging research fields in Physics. From the many questions still open in this area, knowledge of the type of primary for each event remains as one of the most important issues. All of the cosmic rays observatories have been trying to solve this question for at least six decades, but have not yet succeeded. The main obstacle is the impossibility of directly detecting high energy primary events, being necessary to use Monte Carlo models and simulations to characterize generated particles cascades. This work presents the results attained using a simulated dataset that was provided by the Monte Carlo code CORSIKA, which is a simulator of high energy particles interactions with the atmosphere, resulting in a cascade of secondary particles extending for a few kilometers (in diameter) at ground level. Using this simulated data, a set of machine learning classifiers have been designed and trained, and their computational cost and effectiveness compared, when classifying the type of primary under ideal measuring conditions. Additionally, a feature selection algorithm has allowed for identifying the relevance of the considered features. The results confirm the importance of the electromagnetic-muonic component separation from signal data measured for the problem. The obtained results are quite encouraging and open new work lines for future more restrictive simulations.Spanish Ministry of Science, Innovation and Universities FPA2017-85197-P RTI2018-101674-B-I00European Union (EU)CENAPAD-SP (Centro Nacional de Processamento de Alto Desempenho em Sao Paulo) UNICAMP/FINEP - MCTFundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)National Council for Scientific and Technological Development (CNPq) 2016/19764-9404993/2016-

A search for ultra-high-energy photons at the Pierre Auger Observatory exploiting air-shower universality

The Pierre Auger Observatory is the most sensitive detector to primary photons with energies above ∼0.2 EeV. It measures extensive air showers using a hybrid technique that combines a fluorescence detector (FD) with a ground array of particle detectors (SD). The signatures of a photon-induced air shower are a larger atmospheric depth at the shower maximum (X$_{max}$) and a steeper lateral distribution function, along with a lower number of muons with respect to the bulk of hadron-induced background. Using observables measured by the FD and SD, three photon searches in different energy bands are performed. In particular, between threshold energies of 1-10 EeV, a new analysis technique has been developed by combining the FD-based measurement of X$_{max}$ with the SD signal through a parameter related to its muon content, derived from the universality of the air showers. This technique has led to a better photon/hadron separation and, consequently, to a higher search sensitivity, resulting in a tighter upper limit than before. The outcome of this new analysis is presented here, along with previous results in the energy ranges below 1 EeV and above 10 EeV. From the data collected by the Pierre Auger Observatory in about 15 years of operation, the most stringent constraints on the fraction of photons in the cosmic flux are set over almost three decades in energy

Study on multi-ELVES in the Pierre Auger Observatory

Since 2013, the four sites of the Fluorescence Detector (FD) of the Pierre Auger Observatory record ELVES with a dedicated trigger. These UV light emissions are correlated to distant lightning strikes. The length of recorded traces has been increased from 100 μs (2013), to 300 μs (2014-16), to 900 μs (2017-present), to progressively extend the observation of the light emission towards the vertical of the causative lightning and beyond. A large fraction of the observed events shows double ELVES within the time window, and, in some cases, even more complex structures are observed. The nature of the multi-ELVES is not completely understood but may be related to the different types of lightning in which they are originated. For example, it is known that Narrow Bipolar Events can produce double ELVES, and Energetic In-cloud Pulses, occurring between the main negative and upper positive charge layer of clouds, can induce double and even quadruple ELVES in the ionosphere. This report shows the seasonal and daily dependence of the time gap, amplitude ratio, and correlation between the pulse widths of the peaks in a sample of 1000+ multi-ELVES events recorded during the period 2014-20. The events have been compared with data from other satellite and ground-based sensing devices to study the correlation of their properties with lightning observables such as altitude and polarity