TY - JOUR
T1 - Evidence for light-by-light scattering in heavy-ion collisions with the ATLAS detector at the LHC
AU - Aaboud, M.
AU - Aad, G.
AU - Abbott, B.
AU - Abdallah, J.
AU - Abdinov, O.
AU - Abeloos, B
AU - Abidi, Sarah
AU - AbouZeid, O.S.
AU - Abraham, NL
AU - Abramowicz, H.
AU - Abreu, R.
AU - Abreu, H.
AU - Abulaiti, Y.
AU - Acharya, B.S.
AU - Adachi, Shin-ichi
AU - Adamczyk, L.
AU - Adelman, J P
AU - Dam, Mogens
AU - Hansen, Jørn Dines
AU - Hansen, Jørgen Beck
AU - Xella, Stefania
AU - Hansen, Peter Henrik
AU - Petersen, Troels Christian
AU - Løvschall-Jensen, Ask Emil
AU - Alonso Diaz, Alejandro
AU - Monk, James William
AU - Pedersen, Lars Egholm
AU - Wiglesworth, Graig
AU - Galster, Gorm Aske Gram Krohn
AU - Stark, Simon Holm
AU - Besjes, Geert-Jan
AU - de Almeida Dias, Flavia
AU - Thiele, Fabian Alexander Jürgen
AU - Bajic, Milena
AU - Barr, J.
PY - 2017/9/5
Y1 - 2017/9/5
N2 - 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.
AB - 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.
U2 - 10.1038/nphys4208
DO - 10.1038/nphys4208
M3 - Journal article
SN - 1745-2473
VL - 13
SP - 852
EP - 858
JO - Nature Physics
JF - Nature Physics
ER -