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

TL;DR

This paper explores how minimal flavour violating models with multiple scalars can explain deviations in B meson mixing observed experimentally, proposing specific scalar interactions and extensions to fit the data.

Contribution

It introduces a model extension with multiple scalars that naturally accounts for the observed CP violation in B meson mixing within the MFV framework.

Findings

MFV models with multiple scalars can explain the dimuon asymmetry

Constraints from electric dipole moments influence scalar couplings

Extended models can naturally produce the required scalar interactions

Abstract

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. We construct an extension of the MFV two scalar doublet model where this occurs naturally.