On theories of enhanced CP violation in B_s,d meson mixing

Understand

The DO collaboration has measured a deviation from the standard model (SM) prediction in the like sign dimuon asymmetry in semileptonic b decay with a significance of 3.2 sigma.

• We discuss how minimal flavour violating (MFV) models with multiple scalar representations can lead to this deviation through tree level exchanges of new MFV scalars.
• We review how the two scalar doublet model can accommodate this result and discuss some of its phenomenology.
• Limits on electric dipole moments suggest that in this model the coupling of the charged scalar to the right handed u-type quarks is suppressed while its coupling to the d-type right handed quarks must be enhanced.