CMS-PAS-SMP-20-016

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
CMS Collaboration
March 2021

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.
Links: CDS record (PDF) ; inSPIRE record ; CADI line (restricted) ; These preliminary results are superseded in this paper, Submitted to PRD. The superseded preliminary plots can be found here.

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