Observation of Light-by-Light Scattering in Ultraperipheral Pb plus Pb Collisions with the ATLAS Detector
- NázevTitle
- Observation of Light-by-Light Scattering in Ultraperipheral Pb plus Pb Collisions with the ATLAS DetectorObservation of Light-by-Light Scattering in Ultraperipheral Pb plus Pb Collisions with the ATLAS Detector
- Druh výsledkuResult type
- Článek v časopiseJournal article
- AutořiAuthors
- G. Aad, B. Abbott, D. C. Abbott, O. Abdinov, B. Ali, K. Augsten, B. Bergmann, M. Havránek, Z. Hubáček, M. Myška, R. Novotný, S. Pospíšil, K. Smolek, A. Sopczak, V. Vacek, P. Vokáč, V. Vrba
- DOIDOI
- 10.1103/PhysRevLett.123.052001
- Časopis / citaceJournal / citation
- Physical Review Letters. 2019, 123(5), ISSN 0031-9007.
- RokYear
- 2019
- JazykLanguage
- eng
- WoSWoS
- 000479003100006
- ScopusScopus
- 2-s2.0-85071896312
- RIVRIV
- RIV/68407700:21220/19:00339167!RIV20-MSM-21220___
- ProjektProject
- Centrum pokročilých aplikovaných přírodních vědCenter for advanced applied sciences; Získávání nových poznatků o mikrosvětě v infrastruktuře CERNAcquiring new pieces of knowledge about micro-world in CERN research infrastructure
AbstraktAbstract
This Letter describes the observation of the light-by-light scattering process, gamma gamma -> gamma gamma, in Pb + Pb collisions at root S-NN = 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 E-T(gamma) > 3 GeV and pseudorapidity vertical bar eta(gamma)vertical bar < 2.4, 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.
This Letter describes the observation of the light-by-light scattering process, gamma gamma -> gamma gamma, in Pb + Pb collisions at root S-NN = 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 E-T(gamma) > 3 GeV and pseudorapidity vertical bar eta(gamma)vertical bar < 2.4, 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.