Electroweak production of two jets in association with a Z boson in proton–proton collisions at $\sqrt s$ = 13 TeV

Abstract

A measurement of the electroweak (EW) production of two jets in association with a $Z$ boson in proton-proton collisions at $\sqrt s$ = 13TeV is presented, based on data recorded in 2016 by the CMS experiment at the LHC corresponding to an integrated luminosity of 35.9 $fb^{-1}$. The measurement is performed in the $ℓℓjj$ final state with ℓ including electrons and muons, and the jets $j$ corresponding to the quarks produced in the hard interaction. The measured cross section in a kinematic region defined by invariant masses $m_{ℓℓ}>50GeV$,$m_{jj}>120GeV$, and transverse momenta $\sigma _\mathrm {EW}(\ell \ell \mathrm {jj})= 534 \pm 20\,\text {(stat)} \pm 57\,\text {(syst) fb}$, in agreement with leading-order standard model predictions. The final state is also used to perform a search for anomalous trilinear gauge couplings. No evidence is found and limits on anomalous trilinear gauge couplings associated with dimension-six operators are given in the framework of an effective field theory. The corresponding 95% confidence level intervals are $-2.6< c_{WWW}/\varLambda ^2 < 2.6\,\text {TeV}^{-2}$ and $ -8.4< c_{W}/\varLambda ^2 < 10.1\,\text {TeV}^{-2}$. The additional jet activity of events in a signal-enriched region is also studied, and the measurements are in agreement with predictions.