We study an extension of the Higgs sector of the minimal supersymmetric standard model (MSSM), considering the effects of new degrees of freedom at the TeV scale and allowing for sources of $CP$ violation beyond the MSSM. We analyze the impact of the beyond-the-MSSM sources of $CP$ violation on the Higgs collider phenomenology and on low energy flavor and $CP$-violating observables. We identify distinct Higgs collider signatures that cannot be realized, either in the case without $CP$-violating phases or in the $CP$-violating MSSM, and investigate the prospects to probe them at the Tevatron and the LHC. The most striking benchmark scenario has three neutral Higgs bosons that all decay dominantly into $W$ boson pairs and that are well within the reach of the 7 TeV LHC run. On the other hand, we also present scenarios with three Higgs bosons that have masses $M_{H_i}\gtrsim 150\mathrm{GeV}$ and decay dominantly into $b\overline{b}$. Such scenarios are much more challenging to probe and can even lie completely outside the reach of the 7 TeV LHC run. We explore complementary scenarios with standard MSSM Higgs signals that allow us to accommodate a nonstandard $B_s$ mixing phase as indicated by D0, as well as the excess in $B_s\to {\mu }^{+}{\mu }^{-}$ candidates recently reported by CDF. We find that, in contrast to the MSSM, a minimal flavor-violating soft sector is sufficient to generate significant corrections to $CP$-violating observables in meson mixing, compatible with Electric Dipole Moment constraints. In particular, a $B_s$ mixing phase $S_{\psi \varphi }\lesssim 0.15$ can be achieved for specific regions of parameter space, compatible with all the presently available experimental constraints on flavor observables. Such a nonstandard $B_s$ mixing phase would unambiguously imply a sizable suppression of $S_{\psi K_S}$ with respect to the standard model prediction and a $\mathrm{BR}(B_s\to {\mu }^{+}{\mu }^{-})$ close to its 95% C.L. upper bound of $1.1\times {10}^{-8}$.

• Received 29 July 2011

DOI:https://doi.org/10.1103/PhysRevD.84.095027