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Search for an L − L gauge boson using Z → 4μ events in proton-proton collisions at √ s = 13 TeV
Name
1-s2.0-S037026931930214X-main.pdf
Description
Published version
Size
1.08 MB
Format
Adobe PDF
Checksum (MD5)
fe7b2be2288ce665e22965b5adfcf96f
Author(s)
CMS Collaboration
Abercrombie, Daniel Robert
Allen, B.
Azzolini, Virginia
Barbieri, Richard Alexander
Baty, Austin Alan
Bauer, Gerry P
Bi, R.
Brandt, S.
Busza, Wit
Publisher
Elsevier BV
Citation
"Search for an L − L gauge boson using Z → 4μ events in proton-proton collisions at √ s = 13 TeV."
Version
Final published version
Abstract
© 2019 The Author(s) A search for a narrow Z ′ gauge boson with a mass between 5 and 70 GeV resulting from an L μ −L τ U(1) local gauge symmetry is reported. Theories that predict such a particle have been proposed as an explanation of various experimental discrepancies, including the lack of a dark matter signal in direct-detection experiments, tension in the measurement of the anomalous magnetic moment of the muon, and reports of possible lepton flavor universality violation in B meson decays. A data sample of proton-proton collisions at a center-of-mass energy of 13 TeV is used, corresponding to an integrated luminosity of 77.3 fb −1 recorded in 2016 and 2017 by the CMS detector at the LHC. Events containing four muons with an invariant mass near the standard model Z boson mass are analyzed, and the selection is further optimized to be sensitive to the events that may contain Z→Z ′ μμ→4μ decays. The event yields are consistent with the standard model predictions. Upper limits of 10 −8 –10 −7 at 95% confidence level are set on the product of branching fractions B(Z→Z ′ μμ)B(Z ′ →μμ), depending on the Z ′ mass, which excludes a Z ′ boson coupling strength to muons above 0.004–0.3. These are the first dedicated limits on L μ −L τ models at the LHC and result in a significant increase in the excluded model parameter space. The results of this search may also be used to constrain the coupling strength of any light Z ′ gauge boson to muons.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
10.1016/J.PHYSLETB.2019.01.072
