Articulo
Measurement of ZZ production in pp collisions at √s = 7 TeV and limits on anomalous ZZZ and ZZγ couplings with the ATLAS detector
Autor
Alonso, Francisco
Anduaga, Xabier Sebastián
Dova, María Teresa
Monticelli, Fernando Gabriel
Tripiana, Martín F.
The ATLAS Collaboration
Institución
Resumen
A measurement of the ZZ production cross section in proton-proton collisions at √s = 7 TeV using data recorded by the ATLAS experiment at the Large Hadron Collider is presented. In a data sample corresponding to an integrated luminosity of 4.6 fb-1 collected in 2011, events are selected that are consistent either with two Z bosons decaying to electrons or muons or with one Z boson decaying to electrons or muons and a second Z boson decaying to neutrinos. The ZZ(*) → ℓ+ℓ-ℓ0+ℓ0- and ZZ → ℓ+ℓ-vv cross sections are measured in restricted phase-space regions. These results are then used to derive the total cross section for ZZ events produced with both Z bosons in the mass range 66 to 116 GeV, σ tot ZZ = 6.7 ± 0.7 (stat.) +0.4 -0.3 (syst.) ± 0.3 (lumi.) pb, which is consistent with the Standard Model prediction of 5.89+0.22 -0.18 pb calculated at next-to-leading order in QCD. The normalized differential cross sections in bins of various kinematic variables are presented. Finally, the differential event yield as a function of the transverse momentum of the leading Z boson is used to set limits on anomalous neutral triple gauge boson couplings in ZZ production. Facultad de Ciencias Exactas