Two Higgs doublet model with vectorlike leptons and contributions to $pp\to WW$ and $H\to WW$

Abstract

We study a two Higgs doublet model extended by vectorlike leptons mixing with one family of standard model leptons. Generated flavor violating couplings between heavy and light leptons can dramatically alter the decay patterns of heavier Higgs bosons. We focus on $pp \to H \to \nu_4 \nu_\mu \to W \mu \nu_\mu$, where $\nu_4$ is a new neutral lepton, and study possible effects of this process on the measurements of $pp \to WW$ and $H \to WW$ since it leads to the same final states. We discuss predictions for contributions to $pp \to WW$ and $H \to WW$ and their correlations from the region of the parameter space that satisfies all available constraints including precision electroweak observables and from pair production of vectorlike leptons. Large contributions, close to current limits, favor small $\tan \beta $ region of the parameter space. We find that, as a result of adopted cuts in experimental analyses, the contribution to $pp \to WW$ can be an order of magnitude larger than the contribution to $H \to WW$. Thus, future precise measurements of $pp\to WW$ will further constrain the parameters of the model. In addition, we also consider possible contributions to $pp\to WW$ from the heavy Higgs decays into a new charged lepton $e_4$ ($H\to e_4 \mu \to W \mu \nu_\mu$), exotic SM Higgs decays, and pair production of vectorlike leptons.