@article{10902/18403, year = {2019}, month = {5}, url = {http://hdl.handle.net/10902/18403}, abstract = {A search for a narrow Z′ gauge boson with a mass between 5 and 70 GeV resulting from an Lμ−Lτ 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 Lμ−Lτ 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.}, publisher = {Elsevier}, publisher = {Physics Letters B 792 (2019) 345-368}, title = {Search for an Lμ − Lτ gauge boson using Z → 4μ events in proton-proton collisions at √s=13 TeV}, author = {Sirunyan, A. M. and Cabrillo Bartolomé, José Iban and Calderón Tazón, Alicia and Chazín Quero, Bárbara and Duarte Campderros, Jorge and Fernández García, Marcos and Fernández Manteca, Pedro José and García Alonso, Andrea and García Ferrero, Juan and Gómez Gramuglio, Gervasio and López Virto, María Amparo and Marco de Lucas, Jesús and Martínez Rivero, Celso and Martínez Ruiz del Árbol, Pablo and Matorras Weinig, Francisco and Piedra Gómez, Jonatan and Prieëls, Cédric and Rodrigo Anoro, Teresa and Ruiz Jimeno, Alberto and Scodellaro, Luca and Trevisani, Nicolo and Vila Álvarez, Iván and Vilar Cortabitarte, Rocío}, }