Evidence for light-by-light scattering in ultraperipheral PbPb collisions at √sNN = 5.02 TeV
Evidence for light-by-light (LbL) scattering, γγ → γγ, in ultraperipheral PbPb collisions at a nucleon-nucleon centerof-mass energy of 5.02 TeV is reported. LbL scattering processes are selected in events with just two photons produced, with transverse energy Eγ T > 2 GeV, pseudorapidity |ηγ| &...
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Elsevier B.V.
2019
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| Online Access: | http://irep.iium.edu.my/71952/ http://irep.iium.edu.my/71952/ http://irep.iium.edu.my/71952/ http://irep.iium.edu.my/71952/1/71952_Evidence%20for%20light-by-light%20scattering_article.pdf http://irep.iium.edu.my/71952/2/71952_Evidence%20for%20light-by-light%20scattering_wos.pdf http://irep.iium.edu.my/71952/3/71952_Evidence%20for%20light-by-light%20scattering_scopus.pdf |
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iium-719522019-07-12T02:08:04Z http://irep.iium.edu.my/71952/ Evidence for light-by-light scattering in ultraperipheral PbPb collisions at √sNN = 5.02 TeV D'Enterria, David Sirunyan, A. M. Tumasyan, A. R. Adam, Wolfgang Ambrogi, Federico Md. Ali, Mohd. Adli Q Science (General) QC Physics Evidence for light-by-light (LbL) scattering, γγ → γγ, in ultraperipheral PbPb collisions at a nucleon-nucleon centerof-mass energy of 5.02 TeV is reported. LbL scattering processes are selected in events with just two photons produced, with transverse energy Eγ T > 2 GeV, pseudorapidity |ηγ| < 2.4; and diphoton invariant mass mγγ > 5 GeV, transverse momentum pγγ T < 1 GeV, and acoplanarity (1 − Δφγγ/π) < 0.01. After all selection criteria, 14 events are observed, compared to 11.1 ± 1.1 (theo) and 3.8 ± 1.3 (stat) events expected for signal and background processes respectively. The significance of the signal excess over the background-only hypothesis is 4.1σ. The measured fiducial LbL scattering cross section, σfid(γγ → γγ) = 122 ± 46 (stat) ±29 (syst) ±4 (theo) nb is consistent with the standard model prediction Elsevier B.V. 2019-02 Article PeerReviewed application/pdf en http://irep.iium.edu.my/71952/1/71952_Evidence%20for%20light-by-light%20scattering_article.pdf application/pdf en http://irep.iium.edu.my/71952/2/71952_Evidence%20for%20light-by-light%20scattering_wos.pdf application/pdf en http://irep.iium.edu.my/71952/3/71952_Evidence%20for%20light-by-light%20scattering_scopus.pdf D'Enterria, David and Sirunyan, A. M. and Tumasyan, A. R. and Adam, Wolfgang and Ambrogi, Federico and Md. Ali, Mohd. Adli (2019) Evidence for light-by-light scattering in ultraperipheral PbPb collisions at √sNN = 5.02 TeV. Nuclear Physics A, 982. pp. 791-794. ISSN 0375-9474 https://reader.elsevier.com/reader/sd/pii/S0375947418302914?token=0A13A963173A3A4ADD05DAA01ACBCEA49094AEDCA32F602BFE1E38CC192E19A0BE190D27AE0C0E742D1E2967CCDAD366 10.1016/j.nuclphysa.2018.10.018 |
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Digital Repository |
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Local University |
| institution |
International Islamic University Malaysia |
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IIUM Repository |
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Online Access |
| language |
English English English |
| topic |
Q Science (General) QC Physics |
| spellingShingle |
Q Science (General) QC Physics D'Enterria, David Sirunyan, A. M. Tumasyan, A. R. Adam, Wolfgang Ambrogi, Federico Md. Ali, Mohd. Adli Evidence for light-by-light scattering in ultraperipheral PbPb collisions at √sNN = 5.02 TeV |
| description |
Evidence for light-by-light (LbL) scattering, γγ → γγ, in ultraperipheral PbPb collisions at a nucleon-nucleon centerof-mass energy of 5.02 TeV is reported. LbL scattering processes are selected in events with just two photons produced,
with transverse energy Eγ
T > 2 GeV, pseudorapidity |ηγ| < 2.4; and diphoton invariant mass mγγ > 5 GeV, transverse
momentum pγγ
T < 1 GeV, and acoplanarity (1 − Δφγγ/π) < 0.01. After all selection criteria, 14 events are observed,
compared to 11.1 ± 1.1 (theo) and 3.8 ± 1.3 (stat) events expected for signal and background processes respectively. The
significance of the signal excess over the background-only hypothesis is 4.1σ. The measured fiducial LbL scattering
cross section, σfid(γγ → γγ) = 122 ± 46 (stat) ±29 (syst) ±4 (theo) nb is consistent with the standard model prediction |
| format |
Article |
| author |
D'Enterria, David Sirunyan, A. M. Tumasyan, A. R. Adam, Wolfgang Ambrogi, Federico Md. Ali, Mohd. Adli |
| author_facet |
D'Enterria, David Sirunyan, A. M. Tumasyan, A. R. Adam, Wolfgang Ambrogi, Federico Md. Ali, Mohd. Adli |
| author_sort |
D'Enterria, David |
| title |
Evidence for light-by-light scattering in ultraperipheral
PbPb collisions at √sNN = 5.02 TeV |
| title_short |
Evidence for light-by-light scattering in ultraperipheral
PbPb collisions at √sNN = 5.02 TeV |
| title_full |
Evidence for light-by-light scattering in ultraperipheral
PbPb collisions at √sNN = 5.02 TeV |
| title_fullStr |
Evidence for light-by-light scattering in ultraperipheral
PbPb collisions at √sNN = 5.02 TeV |
| title_full_unstemmed |
Evidence for light-by-light scattering in ultraperipheral
PbPb collisions at √sNN = 5.02 TeV |
| title_sort |
evidence for light-by-light scattering in ultraperipheral
pbpb collisions at √snn = 5.02 tev |
| publisher |
Elsevier B.V. |
| publishDate |
2019 |
| url |
http://irep.iium.edu.my/71952/ http://irep.iium.edu.my/71952/ http://irep.iium.edu.my/71952/ http://irep.iium.edu.my/71952/1/71952_Evidence%20for%20light-by-light%20scattering_article.pdf http://irep.iium.edu.my/71952/2/71952_Evidence%20for%20light-by-light%20scattering_wos.pdf http://irep.iium.edu.my/71952/3/71952_Evidence%20for%20light-by-light%20scattering_scopus.pdf |
| first_indexed |
2023-09-18T21:42:01Z |
| last_indexed |
2023-09-18T21:42:01Z |
| _version_ |
1777413203659063296 |