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
Experimental issues
Continuum suppression: multidimensional cuts exploiting event topology (Fox-Wolfram moments, thrust...) angle of B-flight direction...
Continuum suppression: multidimensional cuts exploiting event topology (Fox-Wolfram moments, thrust...) angle of B-flight direction...
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
B-→DCP K-
81.2 fb-181.2 fb-1
Preliminary
2211
32
1,2 coscosδ21
RARA
R
Φrr
32
31,2 coscosδ21
sinδsin2
Φrr
Φr
A
D1DCP=+ D2DCP=-D1DCP=+ D2DCP=-
B D1K
D1 = KKD1 = KK
D1 = D1 =
E(GeV)
24.27.2
Observables:asymmetries
branching ratios
Observables:asymmetries
branching ratiosD01,2
1,2 R/RR
)f(Bf)(B
)f (Bf)(B-
-
f
B BB B
A
3 independent equations with 3 unknowns (Φ3 ,r, )
3 independent equations with 3 unknowns (Φ3 ,r, )
2
/R
/R
fBfBf
DKD
D0DKD
1,2
00
1,21,2
B
BB
BB
= 0.17 ± 0.23(stat) ± 0.08(sys) = 1.06 ± 0.26(stat) ± 0.17(sys)
1A
1R
Maria Różańska, INP Kraków
HEP2003 Europhysics Conference –Aachen, July 18th 8
B-→DCP K-
D1=KK, D1=KK,
D2=Ks, Ks, Ks, Ks, Ks’ D2=Ks, Ks, Ks, Ks, Ks’
78 fb-178 fb-1
hep-ex/0304032
179.615 165.414.5
25.06.5 22.16.1
20.55.6 29.96.5
Signal yields extracted with a likelihood fit to the E
= -0.19 ± 0.17(stat) ± 0.05(sys) = 1.41 ± 0.27(stat) ± 0.15(sys) 2A
2R
= 1.21 ± 0.25(stat) ± 0.14(sys)
= 0.06 ± 0.19(stat) ± 0.04(sys) 1A
1R
sin2(Φ3 )≤
r 1/4 | |
sin2(Φ3 )≤
r 1/4 | |
1,2R
21 -RR
Maria Różańska, INP Kraków
HEP2003 Europhysics Conference –Aachen, July 18th 9
Similar analysis can be performed with K*- replacing K-
Similar analysis can be performed with K*- replacing K-
88 fb-188 fb-1
Preliminary
coshel from P→PV
No indication for non-resonant DK
MK*-
D0 → K, K,K 0D0 → K, K,K 0
= -0.02 ± 0.33(stat) ± 0.07(sys) = 0.19 ± 0.50(stat) ± 0.04(sys)
1A
2A 4-*0- 10))0.6()(0.55.2()KD(B sysstatB
B-→DCP K*-
(6.1 ± 1.6(stat) ± 1.7(sys)) x 10-4 CLEO
13.14.34.4.3
D1=K+K-, +D1=K+K-, +
D2=Ks, Ks, KsD2=Ks, Ks, Ks
7.23.6 2.4
Maria Różańska, INP Kraków
HEP2003 Europhysics Conference –Aachen, July 18th 10
B → D*0 K*- ALL
81.2 fb-
1
81.2 fb-
1
PreliminaryB- → D*0 K*- B→V V can be also used,
angular analysis required,
B→V V can be also used,
angular analysis required,
D*0 → D0 0 D*0 → D0
)KDB(**0B
(8.0 ± 1.0(stat) ± 1.2(sys)) x 10-4 (7.7 ± 2.2(stat) ± 2.6(sys)) x 10-4 CLEO
Maria Różańska, INP Kraków
HEP2003 Europhysics Conference –Aachen, July 18th 11
both amplitudes are color suppressed r ~ 0.4
both amplitudes are color suppressed r ~ 0.4
B0 → D0 K(*)0
B0 → D0 K*0 , K*0 → K+- (kaon tags B0
flavour)
rates and asymmetries B0 → D1,2 K*0 ⇒ Φ3
isospin relations ⇒ extract Φ3 and
B0 → D0 K0s , B0 – B0 mixing
time dependent asymmetries
(B0-decay vertex needed)
Maria Różańska, INP Kraków
HEP2003 Europhysics Conference –Aachen, July 18th 12
78 fb-178 fb-1 B0 → D0 K(*)0
PRL 90, 141802 (2003)
M(D0) sidebands
27.07.3
41.08.4
E
5000
5*000
10))0.6()(1.35.0()KD(B
10))0.5()(1.14.8()KD(B
sysstat
sysstat
B
B
50*0*0
50*00
50*0*0
50*00
100.4)KD(B
108.1)KD(B
109.6)KD(B
106.6)KD(B
B
B
B
B
90% CL
Vub.
08.013.0)KD(B
)KD(B
10.025.0)KD(B
)KD(B
*-0
0*00
-0
000
BB
BB
04.022.0)D(B
)D(B2-0
000
BB
Maria Różańska, INP Kraków
HEP2003 Europhysics Conference –Aachen, July 18th 13
PDGPDG
| |||
||
5000
50*00
4-*0*-
4-*0-
4-0-
10))0.6()(1.35.0()KD(B
10))0.5()(1.14.8()KD(B
10))1.2()(1.08.0()KD(B
10))0.5()(5.02.5()KD(B
10)6.073.()KD(B
sysstat
sysstat
sysstat
sysstat
B
B
B
B
B 347±20 @ 78 fb-1 D K 360±20 @ 56 fb-1 D K
70±10 @ 88 fb-1 D K
10±4 @ 78 fb-1 D K
15±5 @ 78 fb-1 D K
Summary of Br’s, event yields, .....
Maria Różańska, INP Kraków
HEP2003 Europhysics Conference –Aachen, July 18th 14
Some other approaches
Atwood,Dunietz, Soni (ADS):
use doubly Cabibbo-suppressed D decays
Dalitz plot analysis of BDK
BDK, Dalitz plot analysis of multibody D decays
( e.g. DKs+-)
................
f)KD(B
f)K(DBallowedsuppr.
suppr.allowed
r ~ 1, Br ~ 10-7
b c b u
uu
us
cu
us
u u u u
Both amplitudes are color allowed
Both amplitudes are color allowed
Maria Różańska, INP Kraków
HEP2003 Europhysics Conference –Aachen, July 18th 15
Summary and outlook
No direct CPV observed in B→DXs, no direct constraints on Φ3
yet,
but there is a steady progress:
new relevant decay modes observed:
B- → D K(*)- D→fCP, CP=+,-
B0 → D K(*)0
o other analyses in progress
accelerator performance
KEKB: Lpeak>1034cm-2 s-1 PEP-II: Lpeak>61033cm-2 s-1
o Belle and BaBar aiming for ≈ 0.5 ab-1 in 2005
some meaningful constraints on Φ3 possible by that time
new theoretical ideas
precise measurements in D sector ........
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