Post on 28-Dec-2015
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