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Compact Muon Solenoid
LHC, CERN

CMS-PAS-SMP-14-011
A search for electroweak-induced production of $\mathrm{W} \gamma$ with two jets and constraints on anomalous quartic gauge couplings in pp collisions at $ \sqrt{s} =$ 8 TeV
Abstract: A search for electroweak-induced production of $ \mathrm{W} \gamma $ with two jets in W leptonic decay mode in pp collisions at $\sqrt{s} =$ 8 TeV is presented. The data sample corresponds to an integrated luminosity of 19.7 fb$^{-1}$ collected by the CMS detector. Candidate events are selected with exactly one muon or electron, missing transverse energy, one photon, and two jets with large rapidity separation. The electroweak contribution is observed with significance of the excess 2.7$\sigma$, the cross section in the fiducial region is measured to be 10.8 $\pm$ 4.1 (stat) $\pm$ 3.4 (syst) $\pm$ 0.3 (lumi) fb, which is consistent with the Standard Model prediction. The upper limit on the electroweak signal strength is 4.3 at 95% confidence level. When only the non-$ \mathrm{W} \gamma $ plus two jets contribution is considered as background, the cross section in the same region is measured to be 23.2 $\pm$ 4.3 (stat) $\pm$ 1.7 (syst) $\pm$ 0.6 (lumi) fb, which is consistent with the Standard Model electroweak+QCD prediction. Experimental limits on dimension eight anomalous quartic gauge couplings $f_{M,0-7}/\Lambda^4$, $f_{T,0-2}/\Lambda^4$, and $f_{T,5-7}/\Lambda^4$ are set at 95% confidence level.
CMS Publications
Compact Muon Solenoid
LHC, CERN