ZZ cross section measurements and limits on anomalous coupling constants for neutral triple gauge boson

The measurement of the $Z$ boson pair production cross section at 7 and 8 TeV is presented. In the Standard Model (SM), a $Z$ boson pair is produced through non-resonant processes or through the decay of a Higgs boson, and the predictions of the SM for this rare electroweak process can be tested wit...

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Detalles Bibliográficos
Autor principal: Pernie, Luca
Lenguaje:eng
Publicado: 2013
Materias:
Acceso en línea:https://dx.doi.org/10.1142/9789814663618_0029
http://cds.cern.ch/record/1640977
Descripción
Sumario:The measurement of the $Z$ boson pair production cross section at 7 and 8 TeV is presented. In the Standard Model (SM), a $Z$ boson pair is produced through non-resonant processes or through the decay of a Higgs boson, and the predictions of the SM for this rare electroweak process can be tested with precision for the first time at the LHC. In addition, new physics can appear as deviations from the SM, e.g. in the $Z$ boson $p_T$ spectrum. This new physics can be parametrized as anomalous coupling constants for neutral triple gauge boson interactions $\gamma$ZZ and ZZZ, which are forbidden at tree level in the SM. Data corresponding to an integrated luminosity of about 5.1 fb$^{-1}$ at 7 TeV and 19.5 fb$^{-1}$ at 8 TeV have been analyzed; 7 TeV data for $2l2\nu$ and $4l$ final states and 8 TeV for $2l2\nu$ final state. The cross-sections measurement is in good agreement with the SM NLO predictions. The data are also analyzed to search for anomalous neutral triple gauge couplings. The sensitivity of the $ZZ \rightarrow 2l2\nu$ channel per fb$^{-1}$ is demonstrated to be comparable to that of the $ZZ \rightarrow 4l$ channel, which lead to the most stringent limits published with only 5 fb$^{-1}$ of data at 7 TeV. Latest public results will be presented and discussed.