Measuring properties of a heavy Higgs boson in the H→ZZ→4ℓ decay

Abstract

Abstract In many extensions of the standard model, there exist a few extra Higgs bosons. Suppose a heavy neutral Higgs boson H is discovered at the LHC, one could then investigate CP and CPT˜ $$ \mathrm{C}\mathrm{P}\tilde{\mathrm{T}} $$ properties of its couplings to a pair of Z bosons through H → ZZ → 4ℓ. We use the helicity-amplitude method to write down the most general form for the angular distributions of the four final-state leptons, which can cover the case of CP-even, -odd, and -mixed state for the Higgs boson. We figure out there are 9 types of angular observables and all the H couplings to Z bosons can be fully determined by exploiting them. A Higgs-boson mass of 260 GeV below the tt threshold is illustrated with full details. With a total of 103 events of H → ZZ → 4ℓ, one can determine the couplings up to 12-20% uncertainties.

Keywords

• Beyond Standard Model
• Higgs Physics