@misc{10481/61704,
year = {2019},
month = {7},
url = {http://hdl.handle.net/10481/61704},
abstract = {This letter describes the observation of the light-by-light scattering process, γγ→γγ, in Pb+Pb collisions at sNN−−−√ = 5.02 TeV. The analysis is conducted using a data sample corresponding to an integrated luminosity of 1.73 nb−1, collected in November 2018 by the ATLAS experiment at the LHC. Light-by-light scattering candidates are selected in events with two photons produced exclusively, each with transverse energy EγT>3 GeV and pseudorapidity |ηγ|<2.37, diphoton invariant mass above 6 GeV, and small diphoton transverse momentum and acoplanarity. After applying all selection criteria, 59 candidate events are observed for a background expectation of 12 ± 3 events. The observed excess of events over the expected background has a significance of 8.2 standard deviations. The measured fiducial cross section is 78 ± 13 (stat.) ± 7 (syst.) ± 3 (lumi.) nb.},
organization = {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 and CEA-DRF/IRFU, France; SRNSFG,
Georgia; BMBF, HGF, and MPG, Germany; GSRT,
Greece; RGC, 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; MES of Russia and NRC KI, Russian
Federation; JINR; MESTD, Serbia; MSSR, Slovakia;
ARRS and MIZŠ, 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, CANARIE, CRC, and
Compute Canada, Canada; COST, ERC, ERDF, Horizon
2020, and Marie Skłodowska-Curie Actions, European
Union; Investissements d’ Avenir Labex and Idex, ANR,
France; DFG and AvH Foundation, Germany; Herakleitos,
Thales, and Aristeia Programmes co-financed by EU-ESF
and the Greek NSRF, Greece; BSF-NSF and GIF, Israel;
CERCA Programme Generalitat de Catalunya, Spain; The
Royal Society and Leverhulme Trust, United Kingdom.},
publisher = {American Physical Society},
title = {Observation of light-by-light scattering in ultraperipheral Pb+Pb collisions with the ATLAS detector},
doi = {10.1103/PhysRevLett.123.052001},
author = {Aad, G. and Aguilar Saavedra, Juan Antonio and Atlas Collaboration},
}