Study of the material of the ATLAS inner detector for Run 2 of the LHC

Abstract

WOS: 000417761100006 ; The ATLAS inner detector comprises three different sub-detectors: the pixel detector, the silicon strip tracker, and the transition-radiation drift-tube tracker. The Insertable B-Layer, a new innermost pixel layer, was installed during the shutdown period in 2014, together with modifications to the layout of the cables and support structures of the existing pixel detector. The material in the inner detector is studied with several methods, using a low-luminosity root s = 13 TeV pp collision sample corresponding to around 2.0 nb(-1) collected in 2015 with the ATLAS experiment at the LHC. In this paper, the material within the innermost barrel region is studied using reconstructed hadronic interaction and photon conversion vertices. For the forward rapidity region, the material is probed by a measurement of the efficiency with which single tracks reconstructed from pixel detector hits alone can be extended with hits on the track in the strip layers. The results of these studies have been taken into account in an improved description of the material in the ATLAS inner detector simulation, resulting in a reduction in the uncertainties associated with the charged-particle reconstruction efficiency determined from simulation. ; ANPCyT, ArgentinaANPCyT; YerPhI, Armenia; ARC, AustraliaAustralian Research Council; BMWFW, Austria; FWF, AustriaAustrian Science Fund (FWF); ANAS, AzerbaijanAzerbaijan National Academy of Sciences (ANAS); SSTC, Belarus; CNPq, BrazilNational Council for Scientific and Technological Development (CNPq); FAPESP, BrazilFundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); NSERC, CanadaNatural Sciences and Engineering Research Council of Canada; NRC, Canada; CFI, CanadaCanada Foundation for Innovation; CERN; CONICYT, ChileComision Nacional de Investigacion Cientifica y Tecnologica (CONICYT); CAS, ChinaChinese Academy of Sciences; MOST, ChinaMinistry of Science and Technology, China; NSFC, ChinaNational Natural Science Foundation of China; COLCIENCIAS, ColombiaDepartamento Administrativo de Ciencia, Tecnologia e Innovacion Colciencias; MSMT CR, Czech RepublicMinistry of Education, Youth & Sports - Czech RepublicCzech Republic Government; MPO CR, Czech RepublicCzech Republic Government; VSC CR, Czech RepublicCzech Republic Government; DNRF, Denmark; DNSRC, DenmarkDanish Natural Science Research Council; IN2P3-CNRS, FranceCentre National de la Recherche Scientifique (CNRS); CEA-DSM/IRFU, France; SRNSF, Georgia; BMBF, GermanyFederal Ministry of Education & Research (BMBF); HGF, Germany; MPG, GermanyMax Planck Society; GSRT, GreeceGreek Ministry of Development-GSRT; RGC, China; Hong Kong SAR, China; ISF, IsraelIsrael Science Foundation; I-CORE , Israel; Benoziyo Center, Israel; INFN, ItalyIstituto Nazionale di Fisica Nucleare; MEXT, JapanMinistry of Education, Culture, Sports, Science and Technology, Japan (MEXT); JSPS, JapanMinistry of Education, Culture, Sports, Science and Technology, Japan (MEXT)Japan Society for the Promotion of Science; CNRST, Morocco; NWO, NetherlandsNetherlands Organization for Scientific Research (NWO)Netherlands Government; RCN, Norway; MNiSW, PolandMinistry of Science and Higher Education, Poland; NCN, Poland; FCT, PortugalPortuguese Foundation for Science and Technology; MNE/IFA, Romania; MES of Russia; NRC KI, Russian Federation; JINR; MESTD, Serbia; MSSR, Slovakia; ARRS, SloveniaSlovenian Research Agency - Slovenia; MIZS, Slovenia; DST/NRF, South Africa; MINECO, Spain; SRC, Sweden; Wallenberg Foundation, Sweden; SERI, Switzerland; SNSF, SwitzerlandSwiss National Science Foundation (SNSF); Canton of Bern, Switzerland; MOST, TaiwanMinistry of Science and Technology, Taiwan; TAEK, TurkeyMinistry of Energy & Natural Resources - Turkey; STFC, United KingdomScience & Technology Facilities Council (STFC); DOE, United States of AmericaUnited States Department of Energy (DOE); NSF, United States of AmericaNational Science Foundation (NSF); BCKDF, Canada; Canada Council, Canada; CANARIE, Canada; CRC, Canada; Compute Canada, Canada; FQRNT, CanadaFQRNT; Ontario Innovation Trust, Canada; EPLANET, European UnionEuropean Union (EU); ERC, European UnionEuropean Union (EU)European Research Council (ERC); ERDF, European UnionEuropean Union (EU); FP7, European UnionEuropean Union (EU); Horizon, European Union; Marie Sklodowska-Curie Actions, European UnionEuropean Union (EU); Investissement d'Avenir Labex, FranceFrench National Research Agency (ANR); ANR, FranceFrench National Research Agency (ANR); Region Auvergne, FranceRegion Auvergne-Rhone-Alpes; Fondation Partager le Savoir, France; DFG, GermanyGerman Research Foundation (DFG); AvH Foundation, GermanyAlexander von Humboldt Foundation; Herakleitos programme - EU-ESF; Thales programme - EU-ESF; Aristeia programme - EU-ESF; Greek NSRFGreek Ministry of Development-GSRT; BSF, IsraelUS-Israel Binational Science Foundation; GIF, IsraelGerman-Israeli Foundation for Scientific Research and Development; Minerva, Israel; BRF, Norway; CERCA Programme Generalitat de Catalunya, Spain; Generalitat Valenciana, SpainGeneralitat Valenciana; Royal Society, United KingdomRoyal Society of London; Leverhulme Trust, United KingdomLeverhulme Trust; Canton of Geneva, Switzerland; Investissement d'Avenir Idex, FranceFrench National Research Agency (ANR); ANPCyT, ArgentinaANPCyT; YerPhI, Armenia; ARC, AustraliaAustralian Research Council; BMWFW, Austria; FWF, AustriaAustrian Science Fund (FWF); ANAS, AzerbaijanAzerbaijan National Academy of Sciences (ANAS); SSTC, Belarus; CNPq, BrazilNational Council for Scientific and Technological Development (CNPq); FAPESP, BrazilFundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); NSERC, CanadaNatural Sciences and Engineering Research Council of Canada; NRC, Canada; CFI, CanadaCanada Foundation for Innovation; CERN; CONICYT, ChileComision Nacional de Investigacion Cientifica y Tecnologica (CONICYT); CAS, ChinaChinese Academy of Sciences; MOST, ChinaMinistry of Science and Technology, China; NSFC, ChinaNational Natural Science Foundation of China; COLCIENCIAS, ColombiaDepartamento Administrativo de Ciencia, Tecnologia e Innovacion Colciencias; MSMT CR, Czech RepublicMinistry of Education, Youth & Sports - Czech RepublicCzech Republic Government; MPO CR, Czech RepublicCzech Republic Government; VSC CR, Czech RepublicCzech Republic Government; DNRF, Denmark; DNSRC, DenmarkDanish Natural Science Research Council; IN2P3-CNRS, FranceCentre National de la Recherche Scientifique (CNRS); CEA-DSM/IRFU, France; SRNSF, Georgia; BMBF, GermanyFederal Ministry of Education & Research (BMBF); HGF, Germany; MPG, GermanyMax Planck Society; GSRT, GreeceGreek Ministry of Development-GSRT; RGC, China; Hong Kong SAR, China; ISF, IsraelIsrael Science Foundation; I-CORE , Israel; Benoziyo Center, Israel; INFN, ItalyIstituto Nazionale di Fisica Nucleare; MEXT, JapanMinistry of Education, Culture, Sports, Science and Technology, Japan (MEXT); JSPS, JapanMinistry of Education, Culture, Sports, Science and Technology, Japan (MEXT)Japan Society for the Promotion of Science; CNRST, Morocco; NWO, NetherlandsNetherlands Organization for Scientific Research (NWO)Netherlands Government; RCN, Norway; MNiSW, PolandMinistry of Science and Higher Education, Poland; NCN, Poland; FCT, PortugalPortuguese Foundation for Science and Technology; MNE/IFA, Romania; MES of Russia; NRC KI, Russian Federation; JINR; MESTD, Serbia; MSSR, Slovakia; ARRS, SloveniaSlovenian Research Agency - Slovenia; MIZS, Slovenia; DST/NRF, South Africa; MINECO, Spain; SRC, Sweden; Wallenberg Foundation, Sweden; SERI, Switzerland; SNSF, SwitzerlandSwiss National Science Foundation (SNSF); Canton of Bern, Switzerland; MOST, TaiwanMinistry of Science and Technology, Taiwan; TAEK, TurkeyMinistry of Energy & Natural Resources - Turkey; STFC, United KingdomScience & Technology Facilities Council (STFC); DOE, United States of AmericaUnited States Department of Energy (DOE); NSF, United States of AmericaNational Science Foundation (NSF); BCKDF, Canada; Canada Council, Canada; CANARIE, Canada; CRC, Canada; Compute Canada, Canada; FQRNT, CanadaFQRNT; Ontario Innovation Trust, Canada; EPLANET, European UnionEuropean Union (EU); ERC, European UnionEuropean Union (EU)European Research Council (ERC); ERDF, European UnionEuropean Union (EU); FP7, European UnionEuropean Union (EU); Horizon, European Union; Marie Sklodowska-Curie Actions, European UnionEuropean Union (EU); Investissement d'Avenir Labex, FranceFrench National Research Agency (ANR); ANR, FranceFrench National Research Agency (ANR); Region Auvergne, FranceRegion Auvergne-Rhone-Alpes; Fondation Partager le Savoir, France; DFG, GermanyGerman Research Foundation (DFG); AvH Foundation, GermanyAlexander von Humboldt Foundation; Herakleitos programme - EU-ESF; Thales programme - EU-ESF; Aristeia programme - EU-ESF; Greek NSRFGreek Ministry of Development-GSRT; BSF, IsraelUS-Israel Binational Science Foundation; GIF, IsraelGerman-Israeli Foundation for Scientific Research and Development; Minerva, Israel; BRF, Norway; CERCA Programme Generalitat de Catalunya, Spain; Generalitat Valenciana, SpainGeneralitat Valenciana; Royal Society, United KingdomRoyal Society of London; Leverhulme Trust, United KingdomLeverhulme Trust; Canton of Geneva, Switzerland; Investissement d'Avenir Idex, FranceFrench National Research Agency (ANR) ; We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; CONICYT, Chile; CAS, MOST and NSFC, China; COLCIENCIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF and DNSRC, Denmark; IN2P3-CNRS, CEA-DSM/IRFU, France; SRNSF, Georgia; BMBF, HGF, and MPG, Germany; GSRT, Greece; RGC, Hong Kong SAR, China; ISF, I-CORE and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; NWO, Netherlands; RCN, Norway; MNiSW and NCN, Poland; FCT, Portugal; MNE/IFA, Romania; MES of Russia and NRC KI, Russian Federation; JINR; MESTD, Serbia; MSSR, Slovakia; ARRS and MIZS, Slovenia; DST/NRF, South Africa; MINECO, Spain; SRC and Wallenberg Foundation, Sweden; SERI, SNSF and Cantons of Bern and Geneva, Switzerland; MOST, Taiwan; TAEK, Turkey; STFC, United Kingdom; DOE and NSF, United States of America. In addition, individual groups and members have received support from BCKDF, the Canada Council, CANARIE, CRC, Compute Canada, FQRNT, and the Ontario Innovation Trust, Canada; EPLANET, ERC, ERDF, FP7, Horizon 2020 and Marie Sklodowska-Curie Actions, European Union; Investissements d'Avenir Labex and Idex, ANR, Region Auvergne and Fondation Partager le Savoir, France; DFG and AvH Foundation, Germany; Herakleitos, Thales and Aristeia programmes co-financed by EU-ESF and the Greek NSRF; BSF, GIF and Minerva, Israel; BRF, Norway; CERCA Programme Generalitat de Catalunya, Generalitat Valenciana, Spain; the Royal Society and Leverhulme Trust, United Kingdom.