Measurement of the production cross section for Zγ → ν ν̅ γ in pp collisions at √s=7 TeV and limits on ZZγ and Zγγ triple gauge boson couplings

A measurement of the Zγ→ν ν̄ γ cross section in pp collisions at √s​ = 7 TeV is presented, using data corresponding to an integrated luminosity of 5.0 inverse femtobarns collected with the CMS detector. This measurement is based on the observation of events with an imbalance of transverse energy in excess of 130 GeV and a single photon in the absolute pseudorapidity range |ηetaη| < 1.4 with transverse energy above 145 GeV. The Zγ→ννˉγZgamma o uar{ u}gammaZγ→ννˉγ production cross section is measured to be 21.1 +/- 4.2 (stat.) +/- 4.3 (syst.) +/- 0.5 (lum.) fb, which agrees with the standard model prediction of 21.9 +/- 1.1 fb. The results are combined with the CMS measurement of ZγZgammaZγ production in the l+l−γl^+ l^- gammal+l−γ final state (where l is an electron or a muon) to yield the most stringent limits to date on triple gauge boson couplings: ∣h3Z∣<2.7×10−3,∣h4Z∣<1.3×10−5|h_3^Z| < 2.7 imes 10^{-3}, |h_4^Z| < 1.3 imes 10^{-5}∣h3Z​∣<2.7×10−3,∣h4Z​∣<1.3×10−5 for ZZγZZgammaZZγ and ∣h3γ∣<2.9×10−3,∣h4γ∣<1.5×10−5|h_3^gamma| < 2.9 imes 10^{-3}, |h_4^gamma| < 1.5 imes 10^{-5}∣h3γ​∣<2.9×10−3,∣h4γ​∣<1.5×10−5 for ZγγZgammagammaZγγ couplings.