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Observation of a Higgs Boson in the H to zz to 4L decay channel and using Z to 4L decays as a calibration tool in studies of the Higgs boson properties

A search for the Higgs boson in the decay channel H to ZZ to 4 leptons is performed using data from proton-proton collisions corresponding to and integrated luminosity of 5.1 inverse femtobarns at a center-of-mass energy of 7 TeV and 19.7 inverse femtobarns at a center-of-mass energy of 8 TeV data....

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Detalles Bibliográficos
Autor principal: Snowball, Matthew Alexander
Lenguaje:eng
Publicado: 2014
Materias:
Acceso en línea:http://cds.cern.ch/record/1754329
Descripción
Sumario:A search for the Higgs boson in the decay channel H to ZZ to 4 leptons is performed using data from proton-proton collisions corresponding to and integrated luminosity of 5.1 inverse femtobarns at a center-of-mass energy of 7 TeV and 19.7 inverse femtobarns at a center-of-mass energy of 8 TeV data. A new boson is observed as a narrow resonance with a local significance of 6.8 standard deviations, a measured mass of 125.6 0.4(stat.) 0.2(syst.) GeV, and a total width less than or equal to 3.4 GeV at a 95% confidence level. The production cross section of the new boson times the branching fraction to four leptons is measured to be 0.93^{+0.26}_{-0.23}(stat.)^{0.13}_{0.09}(syst.)$ times that predicted by the standard model. Its spin-parity properties are found to be consistent with the expectations for the Standard Model Higgs boson. In addition, measurements of the Z to 4 lepton mass and width are presented. The mass of Z boson decaying to 4 leptons is found to be 91.16 0.23 GeV while the width is found to be 2.98 +0.54