CMS-PAS-FSQ-12-035

CMS-PAS-FSQ-12-035
Measurement of pure electroweak production of a Z boson in
CMS Collaboration
2013

Abstract: The measurement of the electroweak production cross section of aZ-boson with two foward/backward jets (EWK Zjj) in proton-proton collisions at $\sqrt{s} = 8$ TeV is presented based on a data sample recorded by the CMS experiment at the LHC with an integrated luminosity of 19.7 fb $^{-1}$ . Different methods are used to extract the signal, including a data-driven approach that models the QCD Zjj background based on $\gamma$ jj events. The cross section for this process is measured in di-electron and di-muon final states in the kinematic region $m_{\ell\ell} >50$ GeV, $m_{\rm jj} >120$ GeV, transverse momenta $p_{{\rm T}j} > 25$ GeV and pseudorapidity $\lvert\eta_j\rvert< 5$ . The measurement, combining different methods and channels, yields $\sigma=226 \pm 26_{\rm stat} \pm 35_{\rm syst}~~{\rm fb}$ , in agreement with the theoretical cross section. The hadronic activity in events with Z-boson production in association with jets is also studied, in particular in the rapidity interval between the jets.
Links: CDS record (PDF) ; inSPIRE record ; Public twiki page ; CADI line (restricted) ; These preliminary results are superseded in this paper, EPJC 75 (2015) 66. The superseded preliminary plots can be found here.

CMS Publications