Higgs search in H→ZZ→llqq

Higgs mass limits  We have been involved in the search for the Higgs boson in the decay into a pair of leptons and two jets from quark fragmentation. The identification of b quarks in the final state allows to reduce the background from Standard Model processes.

We are now involved in the measurement of the Higgs boson properties. The decay channel with 4 leptons in the final state is very well suited for measuring the eigenvalues of parity and charge conjugation of the newly discovered resonance.
The signal selection strategy is based on the reconstruction and identification of the 4 final state leptons (4e, 4μ and 2e2μ), whose transverse momentum spectra vary between 5 and 200 GeV/c, where one of them has always low momentum (pT<10 GeV/c).
The data analysis and the determination of the new signal properties are carried out with appropriate statistical techniques for hypothesis testing, developed by building "likelihood" functions for the modeling of complex statistical fluctuations and of systematic uncertainties related to the experimental apparatus and background estimation. The Higgs boson is predicted to be a scalar particle with positive eigenvalues of parity and charge conjugation (JPC = 0++) and these parameters can be extracted separately from angular variables in both production and decay processes.