Journal Article Ppublish
PubMed: 42727009 DOI: 10.1103/gdbv-wnpp
Evidence of ZZγ Production and Observation of 4ℓγ in Proton-Proton Collisions at sqrt[s]=13 TeV.
Phys Rev Lett 137(9):091805
Authors: A Hayrapetyan, V Makarenko, A Tumasyan, W Adam, L Benato, T Bergauer, M Dragicevic, P S Hussain, M Jeitler, N Krammer, A Li, D Liko, M Matthewman, J Schieck, R Schöfbeck, M Shooshtari, M Sonawane, N Van Den Bossche, W Waltenberger, C-E Wulz, T Janssen, H Kwon, D Ocampo Henao, T Van Laer, P Van Mechelen, D Ahmadi, J Bierkens, N Breugelmans, J D'Hondt, S Dansana, A De Moor, M Delcourt, C Gupta, F Heyen, Y Hong, P Kashko, S Lowette, I Makarenko, S Nandakumar, S Tavernier, M Tytgat, G P Van Onsem, S Van Putte, D Vannerom, T Wybouw, A Beshr, B Bilin, F Caviglia Roman, B Clerbaux, A K Das … and 2459 other authors
Affiliations
- Yerevan Physics Institute, Yerevan, Armenia.
- Institut für Hochenergiephysik, Vienna, Austria.
- Universiteit Antwerpen, Antwerpen, Belgium.
- Vrije Universiteit Brussel, Brussel, Belgium.
- Université Libre de Bruxelles, Bruxelles, Belgium.
Abstract
Evidence of the production of two Z bosons and a photon in proton-proton collisions is reported for the first time in CMS. The analysis uses data collected by the CMS experiment between 2016 and 2018 at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb^{-1}. Evidence for the process pp→ZZγ→4ℓγ (ℓ=e, μ), with an observed (expected) significance of 3.7 (3.1) standard deviations in a fiducial region defined by p_{T}^{γ}>20 GeV, |η^{γ}|<2.4, ΔR(ℓ,γ)>0.5, m_{Z} between 60 and 120 GeV, and the invariant mass of either of the two Z bosons combined with the photon (m_{Z_{γ}}) larger than 100 GeV, is reported. The measured (predicted) fiducial cross section is 60_{-22}^{+27} ab (47.56±0.04 ab). Additionally, the inclusive production of pp→4ℓγ is studied by removing the m_{Z_{γ}} requirement to include final state radiation where one Z boson decays to 2ℓγ, yielding an observed (expected) significance of 5.0 (4.2) standard deviations and a measured (predicted) fiducial cross section of 156_{-35}^{+39} ab (99.97±0.09 ab).
MeSH
Physics