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

Document Type

Article

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.