CMS collaboration (2146 authors)Hollar, JonathanNayak, ArunaBargassa, PedrameBeirão Da Cruz E Silva, CristóvãoFaccioli, PietroFerreira Parracho, Pedro GuilhermeGallinaro, MicheleNguyen, FedericoRodrigues Antunes, JoaoSeixas, JoaoVarela, JoaoVischia, PietroLloret Iglesias, LaraDavid Tinoco Mendes, AndreMusella, PasqualeSilva, PedroPela, JoaoLeonardo, Nuno2019-02-042019-02-042015-02-10http://dx.doi.org/10.1140/epjc/s10052-014-3232-5http://hdl.handle.net/10400.26/26704The purely electroweak (EW) cross section for the production of two jets in association with a Z boson, in proton–proton collisions at $\sqrt{s}=8\,\text {TeV}$ , is measured using data recorded by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of 19.7 $\,\text {fb}^\text {-1}$ . The electroweak cross section for the $\ell \ell \mathrm {jj}$ final state (with $\ell = \mathrm {e}$ or $\mu $ and j representing the quarks produced in the hard interaction) in the kinematic region defined by $M_{\ell \ell } >50$ $\,\text {GeV}$ , $M_\mathrm {jj} >120$ $\,\text {GeV}$ , transverse momentum $p_\mathrm {T j}> 25$ $\,\text {GeV}$ , and pseudorapidity $|\eta _\mathrm {j} |< 5$ , is found to be $\sigma _\mathrm {EW}(\ell \ell \mathrm {jj})=174 \pm 15\,\text {(stat)}\pm 40\,\text {(syst)}\text {\,fb}$ , in agreement with the standard model prediction. The associated jet activity of the selected events is studied, in particular in a signal-enriched region of phase space, and the measurements are found to be in agreement with QCD predictions.engjournal article2019-02-04