%0 Journal Article
%T Observation of Light-by-Light Scattering in Ultraperipheral Pb plus Pb Collisions with the ATLAS Detector
%A ATLAS Collaboration (Aad, G. et al
%A Alvarez Piqueras, D.
%A Aparisi Pozo, J. A.
%A Bailey, A. J.
%A Barranco Navarro, L.
%A Cabrera Urban, S.
%A Castillo, F. L.
%A Castillo Gimenez, V.
%A Cerda Alberich, L.
%A Costa, M. J.
%A Escobar, C.
%A Estrada Pastor, O.
%A Ferrer, A.
%A Fiorini, L.
%A Fullana Torregrosa, E.
%A Fuster, J.
%A Garcia, C.
%A Garcia Navarro, J. E.
%A Gonzalez de la Hoz, S.
%A Gonzalvo Rodriguez, G. R.
%A Higon-Rodriguez, E.
%A Lacasta, C.
%A Lozano Bahilo, J. J.
%A Madaffari, D.
%A Mamuzic, J.
%A Marti-Garcia, S.
%A Melini, D.
%A Miñano, M.
%A Mitsou, V. A.
%A Rodriguez Bosca, S.
%A Rodriguez Rodriguez, D.
%A Ruiz-Martinez, A.
%A Salt, J.
%A Santra, A.
%A Soldevila, U.
%A Sanchez, J.
%A Valero, A.
%A Valls Ferrer, J. A.
%A Vos, M.
%J Physical Review Letters
%D 2019
%V 123
%N 5
%I Amer Physical Soc
%@ 0031-9007
%G English
%F ATLASCollaborationAad_etal2019
%O WOS:000479003100006
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=4107), last updated on Mon, 02 Sep 2019 09:53:43 +0000
%X 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.
%R 10.1103/PhysRevLett.123.052001
%U https://arxiv.org/abs/1904.03536
%U https://doi.org/10.1103/PhysRevLett.123.052001
%P 052001-21pp