Distinctive heavy Higgs boson decays

For a heavy Higgs boson above the $t\overline{t}$ threshold we consider three decay modes that could compete with decay to $t\overline{t}$, even in the alignment limit of a 2-Higgs doublet model. The decays $H\to AZ$, $Z^{\prime }{Z}^{\prime }$ and ${\tau }^{\prime }{\tau }^{\prime }$ show that heavy Higgs decays can be an effective probe of new physics both within and beyond this model.

Figure 1

Bounds on $\alpha B$ as a function of the heavy lepton masses. From high to low the curves are for $M_H=1000\mathrm{GeV}$ (black), $M_H=900\mathrm{GeV}$ (orange), $M_H=800\mathrm{GeV}$ (magenta), $M_H=700\mathrm{GeV}$ (red), $M_H=600\mathrm{GeV}$ (blue), and $M_H=500\mathrm{GeV}$ (cyan).