1. Dimuon CP asymmetry and new physics in Bs-Bsbar mixing Seungwon Baek (Korea U) LHC Workshop, Konkuk U. Aug 11, 2010 Work in progress with A. Alok, D. London

2. Outline Introduction D0 anomaly and NP in Bs-Bsbar mixing Non-universal Z’ model Flavor changing Z model with vector-like b’ Conclusions

3. B physics in the LHC era The SM CKM paradigm has been strongly reinforced in B, D, and K decays. Several rare decays sensitive to NP also support the SM: ΔM d, ΔM s, B→X s γ, ε K, … However, ν-oscillations, evidence for DM, the hierarchy problem of the SM suggests NP, hopefully at TeV scale

4. sin2β measurements involving b→s penguins are ~2σ different from S(B→J/ψ K S ). Lunghi, Soni (2009)

5. ● ● Forward-backward asymmetry in http://www.kek.jp/intra-e/press/2009/BellePress14e.html

6. deviates from the SM by 2.2σ ● HFAG (2008)

7. All these deviations are in b→s transitions These will be much more precisely measured at LHCb – B s →μ + μ - –. –

8. Bs-Bsbar mixing Mass eigenstates: Time evolution: Mass and width difference:

9. D0 like-sign charge asymmetry With 6.1 fb -1 data, D0 measured Wrong sign charge asymmetry : 2.5σ difference

10. If NP only in M 12 s, then, imposing from, NP in can solve the problem ! ???

11. With NP in the decay … No more

12. Mixing induced CPA in B-decay Indirect CPA Exp SM

13. Non-universal Z’ model Tree-level FCNC M 12 Γ 12

14. M 12 Γ 12 Γ 12 (Z’): considered c, τ-loop only, can compete with the SM when

15. L couplings only After imposing constraints

17. Flavor changing Z with VL b’ Introduce vector-like isosinglet b’ 4x4 down-quark mass matrix 3x4 “CKM” matrix V U≡V † V≠1 → Z-mediated FCNC at tree-level

20. Conclusions Explained semileptonic charge asymmetry as well as, In non-universal Z´-model, all the three observables can be accommodated with non- standard operators In FC Z-model with VL b´, large, marginal but cannot explain 1σ of