Muon anomalous magnetic moment in two-Higgs-doublet models with vectorlike leptons
Mariana Frank, Ipsita Saha
Abstract
We show that inclusion of a single generation of vectorlike leptons in the two-Higgs doublet Models significantly enlarges the allowed parameter space consistent with the muon anomalous magnetic moment, as well as with other theoretical and experimental constraints. While previously $(g\ensuremath{-}2{)}_{\ensuremath{\mu}}$ could only be resolved in type-X scenario by requiring a light pseudoscalar Higgs boson and large $\mathrm{tan}\ensuremath{\beta}$, contributions of vectorlike leptons via two-loop Barr Zee diagrams broaden the allowed parameter space, allowing $\mathrm{tan}\ensuremath{\beta}$ as low as 10 and pseudoscalar masses as large as $\mathcal{O}(1\text{ }\text{ }\mathrm{TeV})$, while fulfilling the stringent constraints from precision and flavor observable. Similar results are obtained for type-II scenarios, but there the parameter space is more restricted by flavor observables.