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New Physics in Bs-Bsbar Mixing. Seungwon Baek (Korea U) KISTI Sep 29, 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.
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New Physics in Bs-Bsbar Mixing Seungwon Baek (Korea U) KISTI Sep 29, 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 supported 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 • Also the B-physics experiments are getting more precise …
Lunghi, Soni (2009) sin2β measurements involving b→s penguins are ~2σ different from S(B→J/ψ KS).
● ● Forward-backward asymmetry in http://www.kek.jp/intra-e/press/2009/BellePress14e.html
deviates from the SM by 2.2σ ● HFAG (2008)
However, CDF data shows improved agreement with the SM. M. Heck, SUSY10
All these deviations are in b→s transitions • These will be much more precisely measured at LHCb • Bs→μ+μ- • .
D0 like-sign dimuon charge asymmetry • With 6.1 fb-1 data, D0 measured : difference
D0 like-sign dimuon charge asymmetry • “Wrong sign” charge asymmetry (CPV in mixing) 2.5σ difference
Bs-Bsbar mixing • Mass eigenstates in terms of flavor eigenstates: • Time evolution: • Mass and width difference:
NP in Bs-Bsbar mixing U. Nierste, SUSY10
If NP only in M12s, • then, imposing from , ???
NP both in M12s and M12d ? U. Nierste, SUSY10
NP both in M12s and M12d ? U. Nierste, SUSY10
NP both in M12s and M12d ? U. Nierste, SUSY10 Not enough to fully explain the D0 dimuon asymmetry.
Mixing induced CPA in B-decay I, Yu, KIAS workshop (2010)
Mixing induced CPA in B-decay • Indirect CPA • Exp • SM
NP in Γ12s • NP in can solve the problem ! • The SM tree amplitude b→s c cbar is λ2-suppressed. • The b→s τ τ vertex is weakly constrained.
With NP in the decay b→s f fbar … • NP in b→s c cbar helps explain CPV in both and Chiang et al 2009 • No more
Non-universal Z’ model • Tree-level FCNC • M12Γ12
M12 and Γ12 in the SM • M12 • Γ12
M12 and Γ12 in the Z’ model • M12 • Γ12(Z’): considered c, τ-loop only, can compete with the SM when
Constraints on Z’ FCNC model • We imposed
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
Constrains on the NP coupling • B(B→Xsμμ) sensitivity • 1<q2<6 (GeV2): dominated by photon • 7<q2<12: dominated by charm resonances • 14<q2<mb2 : dominated by Z, W • We use the high q2 data to constrain Z FCNC model
FC Z contributions to asl, Sψϕ,△Γs Cannot explain 1σ of asl, Sψϕ. But enhancement by factor ~40 in asl is possible. Sψϕ: 0.040.1
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´, marginal but cannot explain 1σ of