Measuring properties of a Heavy Higgs boson in the $H\to ZZ\to 4\ell$ decay

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~ properties of its couplings to a pair of $Z$ bosons through $H\to ZZ\to 4\ell$. 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 $t\bar{t}$ threshold is illustrated with full details. With a total of $10^3$ events of $H\to ZZ\to 4\ell$, one can determine the couplings up to 12-20\% uncertainties.

Comments: 23 pages, 4 figures, 3 tables, to appear in JHEP