Yetkin, Elif Aslı2021-01-112021-01-112019-04-181079-71140031-9007https://hdl.handle.net/11411/3074https://doi.org/10.1103/PhysRevLett.122.151802For the first time, a search for the rare decay of the W boson to three charged pions has been performed. Proton-proton collision data recorded by the CMS experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 77.3 fb(-1), have been analyzed. No significant excess is observed above the background expectation. An upper limit of 1.01 x 10(-6) is set at 95% confidence level on the branching fraction of the W boson to three charged pions. This provides a strong motivation for theoretical calculations of this branching fraction.eninfo:eu-repo/semantics/openAccessPAIR PRODUCTIONArticle2-s2.0-8506555680610.1103/PhysRevLett.122.15180231050519Q1WOS:000465182200002