CDF Logo ZZ Cross section measurement in lll'l' and llνν final states
using the full CDF dataset

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ZZ→lll'l'          ZZ→llνν
Combined results


Abstract:

The ZZ production cross section measurement is an important test of the Standard Model: this process is sensitive to predictions of the electroweak couplings and anomalies observed experimentally can be interpreted as hints of new physics. Moreover, the good knowledge of this process is particularly relevant as it is a background for several exotic searches involving production of boson pairs. In this note we report an analysis aiming to measure the ZZ production cross section in the leptonic decay modes lll'l' and llνν using 9.7 fb-1 of integrated luminosity, corresponding to the full dataset collected by CDF. This is an update of the previous measurement done in the lll'l' channel using 4.8 fb-1 and llνν channel using 5.9 fb-1. Since the lll'l' decay mode is quite peculiar, we exploited a clean sample of such events to extract the cross section from a counting experiment. The ZZ→llνν production is overwhelmed by other background processes (mainly Drell-Yan) hence, after a kinematic selection of the candidate events, we exploited an artificial Neural Network to further extract the signal and measure precisely the production cross section. In the four lepton channel we measure a cross section σ(p-pbar→ZZ)=0.99+0.45-0.35(stat.)+0.11-0.07(syst.) pb while in the two leptons and two neutrino we measure σ(p-pbar→ZZ)=1.18+0.32-0.31(stat.)+0.22-0.17(syst.) pb, which are in agreement with the NLO Standard Model prediction σZZNLO= 1.4 ± 0.1 pb.

 

Supporting Documents:

  • The results will be available for public presentation from June 2013
  • More details are provided in the public note
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    General Remarks:

  • The preliminary results will be blessed in the Standard Model group on June 20, 2013
  • Please contact us if you have any questions about including these results in a presentation
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     Updated by Matteo Bauce
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    Last updated: June 20 2013.