Maria Różańska, INP Kraków HEP2003 Europhysics Conference – Aachen, July 18th 1 CPV in B → D (*) K (*) (and B → D K ) in BaBar and Belle Outline: • CPV in B→D (*) X s • theoretical ideas • experimental issues • experimental results B ∓ → D (*)0 K (*)∓ B 0 → D (*)0 K (*)0 • some other approaches • summary
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CPV in B → D (*) K (*) ( and B → D K ) in BaBar and Belle
CPV in B → D (*) K (*) ( and B → D K ) in BaBar and Belle. Outline: CPV in B → D (*) X s theoretical ideas experimental issues experimental results B ∓ → D (*) 0 K (*) ∓ B 0 → D (*) 0 K (*)0 some other approaches summary. Φ 2 ( α ). V td V * tb. V ud V * ub. - PowerPoint PPT Presentation
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Maria Różańska, INP Kraków
HEP2003 Europhysics Conference –Aachen, July 18th 1
CPV in B → D(*) K(*) (and B → D K )in BaBar and Belle
Outline:
• CPV in B→D(*)Xs
• theoretical ideas
• experimental issues
• experimental results
B∓ → D(*)0 K(*)∓
B0 → D(*)0 K(*)0
• some other approaches
• summary
Maria Różańska, INP Kraków
HEP2003 Europhysics Conference –Aachen, July 18th 2
CPV in B → DXs
Φ3(γ )≡ arg(-VudV*ub/
VcdV*cb)
Φ3(γ )≡ arg(-VudV*ub/
VcdV*cb)
VcdV*cb
VtdV*tbVudV*
ub
Φ3(γ)
Φ2(α)
Φ1(β)
CPV in interference between b→c & b→u
B → DXs is a good place to look
A 'A
theoretically clean: only tree diagrams
theoretically clean: only tree diagrams
interference between
B →D(*)0 K( Xs) ⊕ B→ D(*)0 K(Xs)
f
experimentally challenging:
sensitive to
experimentally challenging:
sensitive to AA
r'
Maria Różańska, INP Kraków
HEP2003 Europhysics Conference –Aachen, July 18th 3
D→fCP ( Gronau, London & Wyler
method)
2
DDD
00
CP
δ - relative strong phase
A(B-→D0K-)
δ
2Φ3
δ
2A(B+→DCPK+)
A(B-→D0K-)= A(B+→D0K+)
2A(B-→DCP
K-)
A(B+→D0K+)
amplitude triangles
amplitude triangles
extensions and modifications
various f
various Xs , (D)
many observables ...
statistics required:
∼ 0.5 ab-1
Ways to measure Φ3 in B→DXs
PROBLEMS:
r = A(B-→D0K-)/A(B-→D0K-) ~ 0.1(0.2)
A(B-→D0K-) difficult to measure directly
Maria Różańska, INP Kraków
HEP2003 Europhysics Conference –Aachen, July 18th 4
Experimental issues
*2B
*2beambc pEM
ΔE (B-→D0h-)
E -49 MeV for
DK-
075.0tan)πD(B
)KD(BR 2
2
2K
-
--
Cf
f
B
B
Use beam constraints
to reconstruct B:
Use beam constraints
to reconstruct B:
Apply tight
K-ID cut:
Apply tight
K-ID cut:
*beam
*B EEE
Mbc(GeV)
K/ separation
Babar : dE/dx in SVT & DCH, DIRC
Belle: dE/dx in CDC, TOF, ACC
≥2.5 (K/) separation up to 3.5 GeV
K/ separation
Babar : dE/dx in SVT & DCH, DIRC
Belle: dE/dx in CDC, TOF, ACC
≥2.5 (K/) separation up to 3.5 GeV
Maria Różańska, INP Kraków
HEP2003 Europhysics Conference –Aachen, July 18th 5
Background suppression from other B decays depends on specific final states: veto for some B-decays, ....
Background suppression from other B decays depends on specific final states: veto for some B-decays, ....
Signal extraction: Maximum likelihood fits with signal shape from MC and data control samples, background from side bands and off-resonance data (combinatorial), MC (B-decays)
Signal extraction: Maximum likelihood fits with signal shape from MC and data control samples, background from side bands and off-resonance data (combinatorial), MC (B-decays)
Maria Różańska, INP Kraków
HEP2003 Europhysics Conference –Aachen, July 18th 6
PreliminaryB- → D0 h-
measurements
56 fb-
1
56 fb-
1
D0 →KD0 →KD0 →KD0 →KD0 →K0D0 →K0
E(GeV) E(GeV) E(GeV)
±±
±0.2)%(8.31 0.35 ±0.6 )% (7.7 0.9 ±
0.7)% (9.9 1.3 ±
)πD(B
)KD(BR
0-
-0-
BB
CLEO, hep-ex/0302026 15.3 fb-1
Babar, hep-ex/0207087 56 fb-1
Belle, PRL 87,111801(2001) 10.4 fb-1
h- identified as K
h- identified as K
Signal extracted wit ML fit to the E,Mbc,PID(/K)
For other B→D(*)K- modes see Belle, PRL 87,111801(2001)
Maria Różańska, INP Kraków
HEP2003 Europhysics Conference –Aachen, July 18th 7