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. 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 -0.50 GeV. Spin-parity properties of the Z boson are shown to be consistent with expectation from the Standard Model.