Testing the new CP phase in a supersymmetric model with [formula omitted] family symmetry by [formula omitted] mixing

Kenji Kawashima,Jisuke Kubo,Alexander Lenz

doi:10.1016/j.physletb.2009.09.064

Kenji Kawashima, Jisuke Kubo + Show 1 more

Open Access

https://doi.org/10.1016/j.physletb.2009.09.064

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Abstract

The new contribution to the non-diagonal matrix element M12 of the neutral Bs meson system is investigated in a supersymmetric extension of the standard model based on the discrete Q6 family symmetry. We assume that CP is explicitly, but softly broken only by the b terms in the soft supersymmetry breaking sector. We find that the new contributions to M12 are real, and that nevertheless there exists an observable difference in the CP phase compared with the standard model. We focus our attention on the flavor-specific CP asymmetry afss, and find that afss of the model is mostly negative and its size can be one order of magnitude larger the standard model value. This prediction is consistent with the current experimental value, and might be experimentally tested in future.

Highlights

Recent experimental data from TeVatron, see e.g. [1] give some hints for possible deviations from the standard model (SM) in the Bs mixing system
The dispersive part of these diagrams is denoted by M12, it is due to heavy internal particles and sensitive to possible new physics contributions
The absorptive part of the box-diagrams - denoted by Γ12 - is due to light internal particles and it can not be affected by large new physics contributions, see e.g. [2] for more details

Summary

INTRODUCTION

Recent experimental data from TeVatron, see e.g. [1] give some hints for possible deviations from the standard model (SM) in the Bs mixing system. The standard model predicts very small numerical values for the mixing phases, βs ≈ (2.2 ± 0.6)◦ and φs ≈ (0.24 ± 0.04)◦ [2]. If new physics contributes to M12, φs and −2βs are shifted by the same value, which we denote by φ∆s , see the note added in [7] for more details. Both CDF [8] and D0 [9] did tagged analyses of the decay Bs → J/ψφ and they obtain values for the mixing phase which differ about 2.2 σ [5] from the SM. We find that asfs of the model is mostly negative and can be one order of magnitude larger the SM value in size

THE MODEL

The Yukawa sector and the CKM parameters

Soft-supersymmetry-breaking sector and the phase alignment

The neutral Higgs bosons and their mixing

CONCLUSION