Measurements of the pp→ZZ production cross section and the Z→4ℓ branching fraction, and constraints on anomalous triple gauge couplings at √s =13 TeV
Name
s10052-018-5567-9.pdf
Size
2.11 MB
Format
Adobe PDF
Checksum (MD5)
359104e3e773abf41d03b3a307fb6cd2
Author(s)
Abercrombie, Daniel Robert
Allen, Brandon Leigh
Azzolini, Virginia
Barbieri, Richard Alexander
Baty, Austin Alan
Bi, Ran
Brandt, Stephanie Akemi
Busza, Wit
Cali, Ivan Amos
D'Alfonso, Mariarosaria
Date Issued
February 2018
Journal
The European Physical Journal C
Publisher
Springer Berlin Heidelberg
Citation
CMS Collaboration, et al. “Measurements of the pp→ZZ Production Cross Section and the Z→4ℓ Branching Fraction, and Constraints on Anomalous Triple Gauge Couplings at √s = 13TeV.” The European Physical Journal C, vol. 78, no. 2, Feb. 2018. © 2018, CERN for the benefit of the CMS collaboration
Abstract
Four-lepton production in proton-proton collisions, pp → (Z/γ[superscript ∗]) (Z/γ[superscript ∗]) → 4ℓ, where ℓ= e or μ, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 35.9fb[superscript -1]. The ZZ production cross section, σ(pp→ZZ)=17.2±0.5(stat)±0.7(syst)±0.4(theo)±0.4(lumi) pb, measured using events with two opposite-sign, same-flavor lepton pairs produced in the mass region 60 < m[subscript ℓ+ℓ-] < 120GeV, is consistent with standard model predictions. Differential cross sections are measured and are well described by the theoretical predictions. The Z boson branching fraction to four leptons is measured to be B(Z → 4ℓ) =4.83[superscript +0.23][subscript -0.22](stat)[superscript +0.32][subscript -0.29](syst)±0.08(theo)±0.12(lumi)×10[superscript -6] for events with a four-lepton invariant mass in the range 80 < m[subscript 4ℓ] < 100GeV and a dilepton mass m[subscript ℓℓ]> 4 GeV for all opposite-sign, same-flavor lepton pairs. The results agree with standard model predictions. The invariant mass distribution of the four-lepton system is used to set limits on anomalous ZZZ and ZZγ couplings at 95% confidence level: -0.0012 < f[superscript Z][subscript 4] < 0.0010, -0.0010 < f[superscript Z][subscript 5] < 0.0013, -0.0012 < f[superscript γ][subscript 4] < 0.0013, -0.0012 < f[superscript γ][subscript 5] < 0.0013.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Massachusetts Institute of Technology. Laboratory for Nuclear Science
Terms of Use
Creative Commons Attribution 4.0 International License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1140/epjc/s10052-018-5567-9
