Journal article

Two-particle azimuthal correlations in photonuclear ultraperipheral Pb plus Pb collisions at 5.02 TeV with ATLAS

G Aad, B Abbott, DC Abbott, A Abed Abud, K Abeling, DK Abhayasinghe, SH Abidi, OS AbouZeid, NL Abraham, H Abramowicz, H Abreu, Y Abulaiti, AC Abusleme Hoffman, BS Acharya, B Achkar, L Adam, C Adam Bourdarios, L Adamczyk, L Adamek, J Adelman Show all

PHYSICAL REVIEW C | AMER PHYSICAL SOC | Published : 2021

Abstract

Two-particle long-range azimuthal correlations are measured in photonuclear collisions using 1.7nb-1 of 5.02 TeV Pb+Pb collision data collected by the ATLAS experiment at the CERN Large Hadron Collider. Candidate events are selected using a dedicated high-multiplicity photonuclear event trigger, a combination of information from the zero-degree calorimeters and forward calorimeters, and from pseudorapidity gaps constructed using calorimeter energy clusters and charged-particle tracks. Distributions of event properties are compared between data and Monte Carlo simulations of photonuclear processes. Two-particle correlation functions are formed using charged-particle tracks in the selected eve..

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Grants

Funding Acknowledgements

We thank CERN for the very successful operation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. 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 and ANID, Chile, CAS, MOST, and NSFC, China, COLCIENCIAS, Colombia, MSMT CR, MPO CR, and VSC CR, Czech Republic, DNRF and DNSRC, Denmark, IN2P3-CNRS and CEA-DRF/IRFU, France, SRNSFG, Georgia, BMBF, HGF, and MPG, Germany, GSRT, Greece, RGC and Hong Kong SAR, China, ISF 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, JINR, MES of Russia, and NRC KI, Russian Federation, MESTD, Serbia, MSSR, Slovakia, ARRS and MIZS, Slovenia, DST/NRF, South Africa, MICINN, 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, USA. In addition, individual groups and members have received support from BCKDF, CANARIE, Compute Canada, CRC and IVADO, Canada, Beijing Municipal Science & Technology Commission, China, COST, ERC, ERDF, Horizon 2020, and Marie Sklodowska-Curie Actions, European Union, Investissements d'Avenir Labex, Investissements d'Avenir Idex and ANR, France, DFG and AvH Foundation, Germany, Herakleitos, Thales, and Aristeia programs cofinanced by EU-ESF and the Greek NSRF, Greece, BSF-NSF and GIF, Israel, La Caixa Banking Foundation, CERCA Programme Generalitat de Catalunya, and PROMETEO and GenT Programmes Generalitat Valenciana, Spain, Goran Gustafssons Stiftelse, Sweden, The Royal Society and Leverhulme Trust, United Kingdom. The crucial computing support from all WLCG partners is acknowledged gratefully, in particular from CERN, the ATLAS Tier-1 facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK), and BNL (USA), the Tier-2 facilities worldwide and large non-WLCG resource providers. Major contributors of computing resources are listed in Ref. [67].