Observation of ZZ Production in pp Collisions at √s = 1.96 TeV

Authors

V. M. Abazov, Joint Institute for Nuclear Research, Dubna, Russia
Kenneth A. Bloom, University of Nebraska-LincolnFollow
D0 Collaboration

Date of this Version

October 2008

Comments

Published in PRL 101, 171803 (2008). Copyright 2008. Used by permission.

Abstract

We present an observation for ZZ → ℓ⁺ ℓ^-ℓ‘⁺ℓ‘^- (ℓ, ℓ‘ = e or μ ) production in pp collisions at a center-of-mass energy of √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^-vv, yields a significance of 5.7 standard deviations and a combined cross section of σ (ZZ) = 1.60 ± 0.63(stat)^+0.16 _-0.17 (syst) pb.