Implications of large dimuon CP asymmetry in B_{d,s} decays on minimal flavor violation with low tan beta

TL;DR

The paper explores how a large dimuon CP asymmetry in B_{d,s} decays constrains minimal flavor violation models with low tan beta, identifying specific operators and predicting universal effects on B meson CP asymmetries.

Contribution

It identifies the specific four-quark operators in MFV that can produce the observed CP asymmetry and predicts their effects, constraining the new physics scale and testing MFV structure.

Findings

New physics scale must be below 260 GeV sqrt{tan beta}

Universal effects on S_{psi K} and S_{psi phi} predicted

MFV supersymmetry with low tan beta is excluded

Abstract

The D0 collaboration has recently announced evidence for a dimuon CP asymmetry in B_{d,s} decays of order one percent. If confirmed, this asymmetry requires new physics. We argue that for minimally flavor violating (MFV) new physics, and at low tan beta=v_u/v_d, there are only two four-quark operators (Q_{2,3}) that can provide the required CP violating effect. The scale of such new physics must lie below 260 GeV sqrt{tan beta}. The effect is universal in the B_s and B_d systems, leading to S_{psi K}~sin(2beta)-0.15 and S_{psi phi}~0.25. The effects on epsilon_K and on electric dipole moments are negligible. The most plausible mechanism is tree-level scalar exchange. MFV supersymmetry with low tan beta will be excluded. Finally, we explain how a pattern of deviations from the Standard Model predictions for S_{psi phi}, S_{psi K} and epsilon_K can be used to test MFV and, if MFV holds, to probe its structure in detail.