@article{a57f918ae1584a9db1ab6ed3b68c4549,
title = "Observation of Light-by-Light Scattering in Ultraperipheral Pb+Pb Collisions with the ATLAS Detector",
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 ETγ>3 GeV and pseudorapidity |ηγ|<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.",
author = "G. Aad and B. Abbott and Abbott, \{D. C.\} and O. Abdinov and \{Abed Abud\}, A. and K. Abeling and Abhayasinghe, \{D. K.\} and Abidi, \{S. H.\} and Abouzeid, \{O. S.\} and Abraham, \{N. L.\} and H. Abramowicz and H. Abreu and Y. Abulaiti and Acharya, \{B. S.\} and B. Achkar and S. Adachi and L. Adam and \{Adam Bourdarios\}, C. and L. Adamczyk and L. Adamek and J. Adelman and M. Adersberger and A. Adiguzel and S. Adorni and T. Adye and Affolder, \{A. A.\} and Y. Afik and C. Agapopoulou and Agaras, \{M. N.\} and A. Aggarwal and C. Agheorghiesei and Aguilar-Saavedra, \{J. A.\} and F. Ahmadov and Ahmed, \{W. S.\} and X. Ai and G. Aielli and S. Akatsuka and {\AA}kesson, \{T. P.A.\} and E. Akilli and Akimov, \{A. V.\} and \{Al Khoury\}, K. and Alberghi, \{G. L.\} and J. Albert and \{Alconada Verzini\}, \{M. J.\} and S. Alderweireldt and M. Aleksa and Aleksandrov, \{I. N.\} and C. Alexa and D. Alexandre and McNamara, \{P. C.\}",
note = "Publisher Copyright: {\textcopyright} 2019 CERN.",
year = "2019",
month = jul,
day = "31",
doi = "10.1103/PhysRevLett.123.052001",
language = "English",
volume = "123",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "5",
}