Aaboud, M.Aad, G.Abbott, B.Abdinov, O.Abeloos, B.Abhayasinghe, D. K.Abidi, S. H.Izen, Joseph M.Meirose, BernhardReeves, KendallATLAS Collaboration2019-10-312019-10-312019-04-051126-6708https://hdl.handle.net/10735.1/7060A measurement of the four-lepton invariant mass spectrum is made with the ATLAS detector, using an integrated luminosity of 36.1 fb⁻¹ of proton-proton collisions at √s = 13 TeV delivered by the Large Hadron Collider. The differential cross-section is measured for events containing two same-flavour opposite-sign lepton pairs. It exhibits a rich structure, with different mass regions dominated in the Standard Model by single Z boson production, Higgs boson production, and Z boson pair production, and non-negligible interference effects at high invariant masses. The measurement is compared with state-of-the-art Standard Model calculations, which are found to be consistent with the data. These calculations are used to interpret the data in terms of gg → ZZ → 4ℓ and Z → 4ℓ subprocesses, and to place constraints on a possible contribution from physics beyond the Standard Model. ©2019 The Author(s).enCC BY 4.0 (Attribution)©2019 The Authorshttp://creativecommons.org/licenses/by/4.0/Leptons (Nuclear physics)Proton-proton interactionsLarge Hadron Collider (France and Switzerland)Standard model (Nuclear physics)Z bosonsHiggs bosonsarticleAaboud, M., G. Aad, B. Abbott, O. Abdinov, et al. 2019. "Measurement of the four-lepton invariant mass spectrum in 13 TeV proton-proton collisions with the ATLAS detector." Journal of High Energy Physics 2019(4): art. 048, doi: 10.1007/JHEP04(2019)0482019