Higgs to ZZ to four leptons

Higgs to ZZ to four leptons is one of the three decay channels which contributed to the discovery of the Higgs-like boson in 2012. On one of the early figures shown below, a peak is visible around 125 GeV in the four lepton invariant mass distribution.


Over the years, we have moved from discovery to precision physics and search for rare processes. The group members are involved in the H -> ZZ* -> 4l in the electron channel, with the following activities:

  • Final analysis of Run 1 data : electron identification efficiency at low energy using J/Psi decays. Data driven techniques for background level studies.
  • Run 2 data : calorimeter inter-calibration and acceptance optimisation. Study of the separation of the Higgs production modes (VBF, VH), measurement of the couplings and possible deviations with effective field theory (EFT) using Simulation Based Inference an advanced Machine Learning technique.

Group members: Lydia Iconomidou-Fayard (staff), David Rousseau (staff), RD Schaffer (staff), Reisaburo Tanaka (staff), Arnaud Maury (student).