The production of a prompt photon in association with a Z boson is studied in proton-proton collisions at a centre-of-mass energy √s = 13 TeV. The analysis uses a data sample with an integrated luminosity of 139 fb −1 collected by the ATLAS detector at the LHC from 2015 to 2018. The production cross-section for the process pp → ℓ +ℓ −γ + X (ℓ = e, μ) is measured within a fiducial phase-space region defined by kinematic requirements on the photon and the leptons, and by isolation requirements on the photon. An experimental precision of 2.9% is achieved for the fiducial cross-section. Differential cross-sections are measured as a function of each of six kinematic variables characterising the ℓ +ℓ −γ system. The data are compared with theoretical predictions based on next-to-leading-order and next-to-next-to-leading-order perturbative QCD calculations. The impact of next-to-leading-order electroweak corrections is also considered. [Figure not available: see fulltext.].
Bibliographical note51 pages in total, author list starting page 35, 7 figures, 6 tables, published in JHEP. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2018-04/
- Hadron-Hadron scattering (experiments)
ASJC Scopus subject areas
- Nuclear and High Energy Physics