First evidence of new physics in b ↔ stransitions

CP violation in B{s} mixing from heavy Higgs boson exchange

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}-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{-}→τν and B{s}→μ^{+}μ{-} 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}-B{s} mixing but also in ΔB=1 transitions or in B{d}-B{d} mixing.