2018/08/31 by CMS Collaboration, A. M. Sirunyan, A. Tumasyan +98 · 101 citations
Physics and Astronomy · #Anomalous magnetic dipole moment #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Electron #Gauge (firearms) #Gauge boson #Gauge theory #Invariant mass #Large Hadron Collider #Lepton #Meson #Muon #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Physics beyond the Standard Model #Standard Model (mathematical formulation) #hep-ex
paper · pdf · doi:10.1016/j.physletb.2019.01.072
published in Physics Letters B 792, 345-368 (Elsevier BV) · Replaced with the published version. Added the journal reference. All the figures and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/EXO-18-008 (CMS Public Pages)
openalex created_date 2018/09/27 · openalex publication_date 2019/03/28 · arxiv created 2019/04/11 · arxiv updated 2019/04/12 · openalex updated_date 2026/08/06
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 ′ μ μ → 4 μ 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 ′ μ μ ) B ( Z ′ → μ μ ) , 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.