Combination of results from the ATLAS and CMS experiments on anomalous triple gauge couplings in ZZ production from pp collisions at a centre-of-mass energy of 7 TeV at the LHC

A procedure is presented to combine data from the ATLAS and CMS experiments on $ZZ$ production to obtain constraints on anomalous neutral triple gauge boson couplings. Statistical and systematic uncertainties and their correlations are taken into account. Data from $pp$ collisions at a center-of-mass energy of 7 TeV delivered by the LHC are used. The datasets correspond to integrated luminosities of 4.6 and 5.0 $\rm{fb^{−1}}$ for ATLAS and CMS, respectively. The combination is performed in the fully leptonic decay channels ZZ → 2l2ν (ATLAS) and ZZ → 4l (ATLAS, CMS). Combined limits on the coupling parameters are −0.010 < f4γ < 0.011, −0.0087 < f4Z < 0.0091, −0.011 < f5γ < 0.010, and −0.0091 < f5Z < 0.0089 at 95% C.L., where all other parameters are fixed to the standard model values. These results represent the first combined limits of the ATLAS and CMS collaborations for anomalous gauge boson couplings.