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

Outline

• Introduction

• D0 anomaly and NP in Bs-Bsbar mixing

• Non-universal Z’ model

• Flavor changing Z model with vector-like b’

• Conclusions

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: ΔMd, ΔMs, B→Xsγ, εK, …

• However, ν-oscillations, evidence for DM, the hierarchy problem of the SM suggests NP, hopefully at TeV scale

• sin2β measurements involving b→s penguins are ~2σ different from S(B→J/ψ KS).

Lunghi, Soni (2009)

●

● Forward-backward asymmetry in

http://www.kek.jp/intra-e/press/2009/BellePress14e.html

deviates from the

SM by 2.2σ●

HFAG (2008)

• All these deviations are in b→s transitions

• These will be much more precisely measured at LHCb– Bs→μ+μ-

– .

–

–

Bs-Bsbar mixing• Mass eigenstates:

• Time evolution:

• Mass and width difference:

D0 like-sign charge asymmetry• With 6.1 fb-1 data, D0 measured

• Wrong sign charge asymmetry

:

2.5σ difference

• If NP only in M12s,

• then, imposing from ,

• NP in can solve the problem !

???

• With NP in the decay …

• No more

Mixing induced CPA in B-decay

• Indirect CPA

• Exp

• SM

Non-universal Z’ model

• Tree-level FCNC

• M12 Γ12

• M12

• Γ12

• Γ12(Z’): considered c, τ-loop only, can compete with the SM when

L couplings only

• After imposing constraints

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

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