The anomalous dimuon charge asymmetry reported by the D0 Collaboration may be due to the tree-level exchange of some spin-0 particles that mediate $CP$ violation in $B_s\mathrm{\text{−}}{\overline{B}}_s$ meson mixing. We show that, for a range of couplings and masses, the heavy neutral states in a two-Higgs doublet model can generate a large charge asymmetry. This range is natural in “uplifted supersymmetry” and may enhance the $B^{-}\to \tau \nu$ and $B_s\to {\mu }^{+}{\mu }^{-}$ decay rates. However, we point out that on general grounds the reported central value of the charge asymmetry requires new physics not only in $B_s\mathrm{\text{−}}{\overline{B}}_s$ mixing but also in $\Delta B=1$ transitions or in $B_d\mathrm{\text{−}}{\overline{B}}_d$ mixing.

• Received 24 May 2010

DOI:https://doi.org/10.1103/PhysRevLett.105.041801