Search for a new scalar resonance decaying to a pair of Z bosons and study of the off-shell Higgs boson in the H->ZZ->2l2nu channel with the CMS detector

by Mr Nicolas Postiau (Université libre de bruxelles)

Monday 12 Mar 2018, 10:00 → 11:00 Europe/Brussels

Large seminar room (Universe)

In 2012, the CMS and ATLAS collaborations have discovered a new particle with a mass close to 125 GeV at the LHC, with properties compatible with the Standard Model (SM) Brout-Englert-Higgs boson. This discovery filled the last missing piece of the Standard Model. However, some phenomena, such as matter-antimatter asymmetry or the presence of dark matter, remain unexplained. Many models beyond the SM predict the existence of other scalar bosons at higher masses, with properties similar to the SM one. In this talk, I will present a search for such a high-mass resonance, performed in the H->ZZ->2l2nu final state (where l represents an electron or a muon). More emphasis will be put on the modelization of the diboson backgrounds, including electroweak corrections, and on systematic uncertainties associated. This final state also allows to study the properties (width and couplings) of the SM scalar boson by studying its off-shell production. Such studies will be also discussed.