Evidence for light-by-light scattering in heavy-ion collisions with the ATLAS detector at the LHC

Journal Article (Journal Article)

Light-by-light scattering (γγ → γγ) is a quantum-mechanical process that is forbidden in the classical theory of electrodynamics. This reaction is accessible at the Large Hadron Collider thanks to the large electromagnetic field strengths generated by ultra-relativistic colliding lead ions. Using 480 μ1 of lead-lead collision data recorded at a centre-of-mass energy per nucleon pair of 5.02 TeV by the ATLAS detector, here we report evidence for light-by-light scattering. A total of 13 candidate events were observed with an expected background of 2.6 ± 0.7 events. After background subtraction and analysis corrections, the fiducial cross-section of the process Pb + Pb (γγ) → Pb(∗) + Pb(∗)γγ,for photon transverse energy ET > 3GeV, photon absolute pseudorapidity |η| <2.4, diphoton invariant mass greater than 6GeV, diphoton transverse momentum lower than 2GeV and diphoton acoplanarity below 0.01, is measured to be 70 ± 24 (stat.) ±17 (syst.) nb, which is in agreement with the standard model predictions.

Full Text

Duke Authors

Cited Authors

  • Aaboud, M; Aad, G; Abbott, B; Abdallah, J; Abdinov, O; Abeloos, B; Abidi, SH; AbouZeid, OS; Abraham, NL; Abramowicz, H; Abreu, H; Abreu, R; Abulaiti, Y; Acharya, BS; Adachi, S; Adamczyk, L; Adelman, J; Adersberger, M; Adye, T; Affolder, AA; Agatonovic-Jovin, T; Agheorghiesei, C; Aguilar-Saavedra, JA; Ahlen, SP; Ahmadov, F; Aielli, G; Akatsuka, S; Akerstedt, H; Åkesson, TPA; Akimov, AV; Alberghi, GL; Albert, J; Alconada Verzini, MJ; Aleksa, M; Aleksandrov, IN; Alexa, C; Alexander, G; Alexopoulos, T; Alhroob, M; Ali, B; Aliev, M; Alimonti, G; Alison, J; Alkire, SP; Allbrooke, BMM; Allen, BW; Allport, PP; Aloisio, A; Alonso, A; Alonso, F; Alpigiani, C; Alshehri, AA; Alstaty, M; Alvarez Gonzalez, B; Álvarez Piqueras, D; Alviggi, MG; Amadio, BT; Amaral Coutinho, Y; Amelung, C; Amidei, D; Amor Dos Santos, SP; Amorim, A; Amoroso, S; Amundsen, G; Anastopoulos, C; Ancu, LS; Andari, N; Andeen, T; Anders, CF; Anders, JK; Anderson, KJ; Andreazza, A; Andrei, V; Angelidakis, S; Angelozzi, I; Angerami, A; Anghinolfi, F; Anisenkov, AV; Anjos, N; Annovi, A; Antel, C; Antonelli, M; Antonov, A; Antrim, DJ; Anulli, F; Aoki, M; Aperio Bella, L; Arabidze, G; Arai, Y; Araque, JP; Araujo Ferraz, V; Arce, ATH; Ardell, RE; Arduh, FA; Arguin, JF; Argyropoulos, S; Arik, M; Armbruster, AJ; Armitage, LJ; Arnaez, O

Published Date

  • September 5, 2017

Published In

Volume / Issue

  • 13 / 9

Start / End Page

  • 852 - 858

Electronic International Standard Serial Number (EISSN)

  • 1745-2481

International Standard Serial Number (ISSN)

  • 1745-2473

Digital Object Identifier (DOI)

  • 10.1038/nphys4208

Citation Source

  • Scopus