Collaboration, D0 and Bertram, Iain and Borissov, Guennadi and Fox, Harald and Williams, Mark and Ratoff, Peter and Love, Peter and Rakitin, Alexander and Sopczak, Andre (2008) Observation of ZZ production in ppbar collisions at sqrt(s) = 1.96 TeV. Physical review letters, 101 (17): 171803. ISSN 1079-7114
Abstract
We present an observation for ZZ -> l+l-l'+l'- (l, l' = e or mu) production in ppbar collisions at a center-of-mass energy of sqrt(s) = 1.96 TeV. Using 1.7 fb-1 of data collected by the D0 experiment at the Fermilab Tevatron Collider, we observe three candidate events with an expected background of 0.14 +0.03 -0.02 events. The significance of this observation is 5.3 standard deviations. The combination of D0 results in this channel, as well as in ZZ -> l+l-nunubar, yields a significance of 5.7 standard deviations and a combined cross section of sigma(ZZ) = 1.60 +/- 0.63 (stat.) +0.16 -0.17 (syst.) pb.