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

Abstract

A measurement of the Zγ→ν(ν-bar)γ cross section in pp collisions at s√=7 TeV is presented, using data corresponding to an integrated luminosity of 5.0 fb(−1) 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 |η| < 1.4 with transverse energy above 145 GeV. The Zγ→ν(ν-bar)γ 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 Zγ production in the ℓ (+) 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: ∣∣h(Z)(3)∣∣<2.7×10(−3) , ∣∣h(Z)(4)∣∣<1.3×10(−5) for ZZγ and ∣∣h(γ)(3)∣∣<2.9×10(−3) , ∣∣h(γ)(4)∣∣<1.5×10(−5) for Zγγ couplings.