Search for $ZZ$ and $Zgamma^*$ production in $parp$ collisions at $sqrts$ = 1.96 TeV and limits on anomalous $ZZZ$ and $ZZgamma^*$ couplings

Abstract

We present a study of four muon, four electron, and two muon two electron events using 1 fb^(-1) of data collected with the D0 detector at the Fermilab Tevatron p-barp Collider at sqrt(s) = 1.96 TeV. Requiring the lepton pair masses to be greater than 30 GeV, we observe one event, consistent with the expected background of 0.13 _s16- 0.03 events and with the predicted standard model ZZ and Zgamma^* production of 1.71 _s16-0.15 events. We set an upper limit on the ZZ and Zgamma^* cross section of 4.4 pb at the 95% C.L. We also derive limits on anomalous neutral trilinear ZZZ and ZZgamma^* gauge couplings. The one-parameter 95%$ C.L. coupling limits with a form factor scale Lambda = 1.2 TeV are -0.28 < f_(40)^Z < 0.28, -0.31 < f_(50)^Z < 0.29, -0.26 < f_(40)^gamma < 0.26, and -0.30 < f_(5 0)^gamma < 0.28.