Search for anomalous couplings in WW and WZ production with single-lepton final states in proton-proton collisions at $\sqrt{s}$ = 13 TeV

Abstract

A search for deviations from the standard model using an effective field theory approach is carried out using the proton-proton collision data set recorded by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$. In this study Wilson coefficients corresponding to dimension-six effective field theory operators that would lead to anomalous gauge boson self-couplings and modified couplings between vector bosons and quarks are constrained. Diboson (WW and WZ) production processes with one W boson decaying to a lepton plus antineutrino or charge conjugate and the second W or Z boson decaying hadronically are considered. Since the contribution from anomalous couplings is expected to be most visible at high energy scales, the focus is on final states where the hadronic decay products of a W or Z boson are merged into a single large-radius jet. A dedicated classifier based on machine learning is employed to separate hadronic W and Z boson decays from background processes. The most stringent constraints to date on the Wilson coefficients of operators corresponding to anomalous triple gauge boson couplings are reported. The bounds set on the couplings between vector bosons and quarks are competitive with those from previous inclusive jet measurements.