LHC has found hints for a Higgs particle of 125 GeV. We investigate the possibility that such a particle is a mixture of scalar and pseudoscalar states. For definiteness, we concentrate on a two-Higgs doublet model with explicit $CP$ violation and soft $Z_2$ violation. Including all Higgs production mechanisms, we determine the current constraints obtained by comparing $h\to \gamma \gamma$ with $h\to V{V}^{*}$, and comment on the information which can be gained by measurements of $h\to b\overline{b}$. We find bounds $|s_2|\lesssim 0.83$ at one sigma, where $|s_2|=0$ ($|s_2|=1$) corresponds to a pure scalar (pure pseudoscalar) state.

• Received 29 May 2012

DOI:https://doi.org/10.1103/PhysRevD.86.015022