Search for $\tau \to 3\mu$ decays using $\tau$ leptons produced in D and B meson decays
CMS-PAS-BPH-17-004, 2019.
The collaboration

Abstract (data abstract)
CERN-LHC. The analysis searches for the LFV decay of the tau lepton to 3 muons, using 13 TeV data collected in proton-proton collisions in 2016 with the CMS detector. The table gives the upper limit at 90\% CL on the branching fraction of the tau lepton to 3 muons.