Speaker
Description
We evaluate the experimental sensitivity to the $CP$-odd admixture in the standard Higgs
boson for the process $e^+e^-\to HZ$. The analysis is performed assuming the future lepton collider CEPC reference
detector operating at $\sqrt{s}=240~\text{GeV}$ with statistics of $5.6~\text{ab}^{-1}$.
Using the \footnotesize WHIZARD \normalsize
generator with the Higgs Characterisation model and the \footnotesize DELPHES \normalsize detector simulation framework we obtain data samples for
different $CP$-odd Higgs admixture parameters $\tilde{c}_{ZZ}$. The initial state radiation (ISR) effects are taken into
account in \footnotesize WHIZARD \normalsize. Angular and ISR energy shift variables are used to distinguish the $CP$-odd and $CP$-even Higgs components.
The upper limit on the $CP$-odd Higgs admixture is improved by 20\% with this method compared to the standard analysis
with three angular variables.
