Search for new particles decaying to ZZ using final states with leptons and jets with the ATLAS detector in sqrt(s) = 7 Tev proton-proton collisions

TL;DR

This paper reports a search for new particles decaying into ZZ boson pairs using ATLAS data at 7 TeV, setting limits on resonance masses and cross sections with no significant excess observed.

Contribution

It presents the first limits on a narrow resonance decaying to ZZ in final states with leptons and jets at 7 TeV, using 1.02/fb of data.

Findings

Excluded RS1 graviton masses between 325 and 845 GeV at 95% CL.

Set a fiducial cross section limit of 0.92 pb for ZZ production.

No significant deviation from Standard Model background observed.

Abstract

A search is presented for a narrow resonance decaying to a pair of Z bosons using data corresponding to 1.02/fb of integrated luminosity collected by the ATLAS experiment from pp collisions at sqrt(s) = 7 TeV. Events containing either four charged leptons (llll) or two charged leptons and two jets (lljj) are analyzed and found to be consistent with the Standard Model background expectation. Lower limits on a resonance mass are set using the Randall-Sundrum (RS1) graviton model as a benchmark. Using both llll and lljj events, an RS1 graviton with k/m_pl = 0.1 and mass between 325 and 845 GeV is excluded at 95% confidence level. In addition, the llll events are used to set a fiducial cross section limit of sigma_fiducial(pp -> X -> ZZ < 0.92 pb at 95% confidence level for any new sources of ZZ production with m_ZZ greater than 300 GeV.