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Compact Muon Solenoid
LHC, CERN

CMS-PAS-SMP-20-016
Measurement of the electroweak production of Z$\gamma$ and two jets in proton-proton collisions at $\sqrt{s} = $ 13 TeV and constraints on dimension 8 operators
Abstract: A measurement of the electroweak (EW) production of a Z boson, a photon, and two jets (Z$\gamma$jj) in proton-proton collisions and constraints on anomalous quartic gauge couplings are presented. Proton-proton collision data corresponding to an integrated luminosity of 137 fb$^{-1}$, collected with the CMS detector at the LHC, at a center of mass collision energy of $\sqrt{s}=$ 13 TeV are used. The signal is extracted by requiring a large dijet invariant mass ($m_{jj}$) and a large pseudorapidity separation between the two jets ($|\Delta\eta_{jj}|$). The fiducial cross section measured for the EW production is $\sigma_{\text{EW}} = $ 5.21 $\pm$ 0.76 fb = 5.21 $\pm$ 0.52 (stat) $\pm$ 0.56 (syst) fb. The observed and expected signal significance is higher than 5 standard deviations. Differential cross sections as functions of the photon, leptons and jets leading transverse momenta distributions and the $m_{jj}$-$|\Delta\eta_{jj}|$ two-dimensional distribution are measured. Exclusion limits on the dimension-eight operators $M_{0-7}$ and $T_{0-2,5-9}$ in the effective field theory framework at 95% confidence level are reported.
CMS Publications
Compact Muon Solenoid
LHC, CERN