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BELLE

B

A N D R E L AT E D R E S U LT S

Dmitri Liventsev (KEK)
on behalf of the Belle collaboration

QFTHEP'2013, St. Peterburg, Russia, June 28, 2013

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BELLE

Belle experiment
? cc, q q , e+ e- (4S ) B B ??

G

KEKB
! !

Asymmetric-energy e+ e- collider: 3.5GeV з 8GeV Record luminosity L = 2.1 з 1034 cm-2 s-1 Designed for C P violation study in B decays Suitable for many other studies: charm, etc.
Dmitri Liventsev - B and related results - 2 / 23

G

Belle
! !

QFTHEP'2013 - June 28, 2013


BELLE

Integrated luminosity

Data was taken in 1999 - 2010 G World largest accumulated luminosity > 1ab-1 ? G 711f b-1 on (4S ) resonance correspond to 772 з 106 B B pairs
G

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BELLE

Standard Model and New Physics

The Standard Model describes known processes very well; G However, there are indications, that the Standard Model is not complete:
G

! !
G

neutrino oscillations, baryon asymmetry, dark matter; too many parameters, hierarchy problem;

There should be something beyond the Standard Model -- New Physics. G New Physics effects are expected to be small, therefore the best way to look is to study rare decays.

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BELLE

New Physics and B
b B
-

W (H )
_

-

-

l

-

u

fBV

ub



_

m2 2 2 G2 mB m2 F (1 - 2 ) fB |Vub |2 B (B ) = ? 8 mB
- -

B

Leptonic B decays are clean since there are no hadronic uncertainties. G Leptonic decays are helicity-suppressed: B (B - e- e ) B (B - Е- Е ) B (B - - ). ? ? ? G Good place to look for New Physics, e.g. charged Higgs exchange: BN P (B - - ) = BS M (B - - ) з rH , ? ? where rH depends on the Higgs model, but not on the mode.
G

In Type II 2HDM (W. S. Hou, PRD 48, 2342 (1993)) r
QFTHEP'2013 - June 28, 2013

H

= (1 -

2 mB m2 H

tan2 )2 .

Dmitri Liventsev - B and related results - 5 / 23


BELLE

Full reconstruction tagging

At B factory events are clearly separated; G (4S ) decays into two B mesons; G All particles (but neutrinos) are detected; G Initial energy is known.
G

We can resonstruct one B meson in hadronic or semileptonic mode (Btag ), reconstruct some particles from the other B meson (Bsig ), and restrict unreconstructed part from the information about the whole event.
D(*) K, , ,... l

B tag

Y(4S)

B sig

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BELLE

Full reconstruction types
Hadronic tagging
!
E = EB - Ebeam , Mbc = q
2 Ebeam - p2 B

G

Exclusive tagging:
I I

Btag is reconstructed as D Bsig is reconstructed;

()

X combination;

Btag signal

d

d

!

Inclusive tagging:
I I

Bsig is reconstructed; The rest of the event is combined into Btag and checked if it is consistent co with B meson hypothesis;

s B ,D =

2 2Ebeam ED -m2 -MD B 2PB PD

!
G

Efficiency 0.2%; B meson is reconstructed as D ; Efficiency 0.7%, but more background;
()

Btag signal

Semileptonic tagging
! !

d

d

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BELLE

Existing experimental results
Belle
+ B = [1.79-0 0 +0 B = [1.54-0 . . . . 56 49 38 37 +0 -0 +0 -0 .46 .51 .29 .31

G

Hadronic tagging, 449M Semileptonic tagging, 657M
G

] з 10 ] з 10

-4 -4

BaBar
+ .57 B = [1.80-0.54 Б 0.24] з 10- 0 B = [1.7 Б 0.8 Б 0.2] з 10-4
з10
-3

Hadronic tagging, 468M Semileptonic tagging, 459M
CKM
fitter
Summer 11

4

0.30

p-value

1.0 0.9

CKM fit w/o BR(B ) Measurements (WA)

0.25

0.8 0.7 0.6

1.0

0.8

BR(B )

2.8 deviation "Tension" in CKM global fit?
p-value

0.20

0.15

0.5 0.4

0.6

0.10

0.4
0.05

0.3 0.2 CKM
fitter
Summer 11

0.2

0.1 0.0
0.7 0.8 0.9 1.0

0.0

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

0.00 0.5

0.6

BR(B ) x 104

sin 2

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BELLE

Improvement in hadronic tagging

Analysis of B with hadronic tag was already made by Belle at smaller data sample (PRL 97, 251802 (2006)). What is new in this analysis?
G G G G G G

All data reprocessed; better efficiency of low pT tracks and neutrals reconstruction; Increased data sample 449M 772M (factor of 1.7); Improved hadronic tagging efficiency NIM A654, 432 (2011) due to new algorythm (factor of 2.2); Improved signal efficiency due to less restricive requirements (factor of 1.8); 2D fit (residual calorimeter energy EE C L vs missing mass Mmiss ) instead of 1D fit (residual energy only); Background rejection with reconstructed KL .

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BELLE

Analysis procedure
? 772M B B PRL 110, 131801 (2013)

- is identified in the e- e , Е- Е , - , and - 0 decay channels; ? ? G No tracks, 0 , KL left in the event after Btag , Bsig reconstruction;
G

!
G

KL efficiency checked in D0 KS , KL KS vs K + K - ;

Backgrounds were simulated by MC; 2 G EE C L , Mmiss distributions were validated in number of samples: - ? sidebands, B 0 sample, Bsig D0 - .
160 140 120 100 80 60 40 20 0 0 0.5

Events / 0.02 (GeV2/c4)

80 70 60 50 40 30 20 10 0 -0.4 -0.2 0 0.2
2 4

Events / 0.05 GeV

- 2 EE C L and Mmiss for Bsig D 0 - ?

Semileptonic control sample

Semileptonic control sample

Dots with error bars -- data Rectangles -- normalized MC

1

0.4

EECL (GeV)
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M2 miss

(GeV /c )

Dmitri Liventsev - B and related results - 10 / 23


BELLE

New B study results
Simultaneous fit to different decay modes. Signal yield N = 62+23 Б 6 -22 + .27 B (B - - ) = [0.72-0.25 Б 0.11] з 10-4 ? 0 Significance = 3.0 including systematic error Results for individual decay modes are consistent. Result at the data sample used earlier is consistent with the previous result.

G G G G G G

Events / 1 (GeV2/c 4)
1 1.2

Events / 0.05 GeV

120 100 80 60 40 20 0 0

25 20 15 10 5 0 0 5 10 15
2

' A
0.2

data background signal

T

0.4

0.6

0.8

20
4

25

30

EECL (GeV)
QFTHEP'2013 - June 28, 2013

M2 miss

(GeV /c )

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BELLE

Comparison of the B results
Latest Belle result Latest Belle average Measured world average CKM global fit
CKM
fitter
Summer 11

B B B B

(B (B (B (B

- - - -





- - - -

? ? ? ?

) ) ) )

= = = =
0.30

+ .27 [0.72-0.25 Б 0.11] з 10 0 [0.96 Б 0.26] з 10-4 [1.15 Б 0.23] з 10-4 + .12 [0.73-0.07 ] з 10-4 0
-3

-4

з10

p-value

1.0 0.9

CKM fit w/o BR(B ) Measurements (WA)

0.25

0.8 0.7 0.6

1.0

0.8

BR(B )

0.20

0.15

0.5 0.4

p-value

0.6

0.10

0.4
0.05

0.3 0.2 CKM
fitter
Summer 11

0.2

0.1 0.0
0.7 0.8 0.9 1.0

0.0

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

0.00 0.5

0.6

BR(B ) x 104

sin 2

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BELLE

Comparison of the B results
Latest Belle result Latest Belle average Measured world average CKM global fit
CKM
fitter
Summer 12 Summer 11

B B B B

(B (B (B (B

- - - -





- - - -

? ? ? ?

) ) ) )

= = = =
0.30

+ .27 [0.72-0.25 Б 0.11] з 10 0 [0.96 Б 0.26] з 10-4 [1.15 Б 0.23] з 10-4 + .12 [0.73-0.07 ] з 10-4 0
-3

-4

з10

p-value

1.0 0.9

CKM fit w/o BR(B ) Measurements (WA)

0.25

0.8 0.7 0.6

1.0

0.8

BR(B )

0.20

0.15

0.5 0.4

p-value

0.6

0.10

0.4
0.05

0.3 0.2 CKM
fitter
Summer 11 Summer 12

0.2

0.1 0.0
0.7 0.8 0.9 1.0

0.0

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

0.00 0.5

0.6

BR(B ) x 104

sin 2

"Tension" in CKM global fit is reduced (1.6 ).
QFTHEP'2013 - June 28, 2013 Dmitri Liventsev - B and related results - 12 / 23


BELLE

B with hadronic tagging
? 772M B B ICHEP2012
signal region signal region

G

SM expectation: B (B ee ) 1 з 10-11 B (B ЕЕ ) 5 з 10-7

Sideband

E

' E

Exclusive hadronic tagging G Zero events observed G B (B ee ) < 3.5 з 10-6 B (B ЕЕ ) < 2.5 з 10-6
G
Sideband

? G Inclusive tag with 277M B B (PLB 647, 67 (2007)) B (B ee ) < 1.7 з 10-6 B (B ЕЕ ) < 0.98 з 10-6
QFTHEP'2013 - June 28, 2013

E

' E

Dmitri Liventsev - B and related results - 13 / 23


BELLE

? B D() study

- - -

? Semileptonic B D() decays are sensitive to charged Higgs and are complementary to leptonic B decay.
b

W (H )

_

c V
cb

To reduce experimental and theoretical uncertainties we use ratio ? B (B D ) R(D) ? B (B D ) SM expected values: ? B (B D ) 0.7% ? B (B D ) 1.4%
R( D )
1

T. Miura, M. Tanaka:hep-ph 0109244
0.8

MSSM
0.6

0.4

SM

0.2

5

10

15

20

25

30

35

40

mW tan mH

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BELLE

B 0 D- + with inclusive tagging
? 535M B B PRL 99, 191807 (2007)

Inclusive tagging is a variant of "full reconstruction" tagging: Bsig is reconstructed as D- + ; G The rest of the event is checked to be consistent with B hypothesis.
G

The first observation of exclusive B decay due to b c transition.
N / 5 MeV/c
2
40

30

20

10

$ $$ W $ A ? ? ? % ?
5.22 5.24 5.26

signal combinatorial background

B (B 0 D- + ) = + .40 (2.02-0.37 Б 0.37)%, 0 5.2 significance

peaking background (D () )

0 5.2

M

tag

[GeV/c2 ]

5.28

5.3

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BELLE

? B+ D
? 657M B B

()0 +

with inclusive tagging
PRD 82, 072005(2010)

Simultaneous extraction of D and D yields; G 2D fit to Mtag and PD .
G
100
a) b)

40

50

D
0 5.2 5.22 5.24

E
5.26 5.28 5.3

20

0 0

0.5

1

1.5

2

? B (B + D0 + ) = + .28 (2.12-0.27 Б 0.29)%, 0 8.1 significance ? B (B + D0 + ) = (0.77 Б 0.22 Б 0.12)%, 3.5 significance

N / 4 MeV/c2

Mtag [GeV/c2] N / 4 MeV/c2
150
c)

N / 80 MeV/c

PD0 [GeV/c] N / 80 MeV/c
100
d)

100

a), b) D 0
50

c), d) D 0

50

D D
0 5.2 5.25

E E
5.3
tag

M

[GeV/c ]

2

0 0

0.5

1

1.5

2

P

D0

[GeV/c]

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BELLE

B0 D
? 657M B B

()- +

with exclusive tagging
arXiv:0910.4301

Exclusive hadronic tagging method; G Simultaneous extraction of D and D yields; 2 G 2D fit to Mmiss and EE C L .
G
Events / 0.4 GeV2/c Events / 0.05 GeV 40
4

30

Data D D* BG

30

Data D D* BG

20

B 0 D

20

2 Mmiss : EE C L < 0.2GeV

10

10

EE C L : 2 Mmiss > 2.0GeV2 /c4
4

0 -2

0 0 2 4 6 8 2 24 Mmiss (GeV /c ) Data D D* BG Events / 0.05 GeV 0 0.25 0.5 0.75 1 ECL Eextra(GeV) Data D D* BG

B (B 0 D- + ) = + .46 + .13 (1.01-0.41 -0.11 Б 0.10)%, 0 0 2.6 significance B (B 0 D- + ) = + .75 + .31 (2.56-0.66 -0.22 Б 0.10)% 0 0 4.7 significance
+ .19 + .11 R(D0 ) = 0.70-0.18 -0.09 0 0 + .11 + .06 R(D0 ) = 0.47-0.10 -0.07 0 0

Events / 0.4 GeV2/c

40

20 15 10

30

B

0

D



20

10

5 0 0 2 4 6 8 2 Mmiss (GeV2/c4) 0 0.25 0.5 0.75 1 ECL Eextra(GeV)

0 -2

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BELLE

? B+ D
? 657M B B

()0 +

with exclusive tagging
arXiv:0910.4301

Exclusive hadronic tagging method; G Simultaneous extraction of D and D yields; 2 G 2D fit to Mmiss and EE C L .
G
Events / 0.05 GeV Events / 0.4 GeV2/c 10 8 6 4 2 2 0 -2 0 0 2 4 6 8 2 24 Mmiss (GeV /c ) Data D D* BG Events / 0.05 GeV 0 0.25 0.5 0.75 1 ECL Eextra(GeV) Data D D* BG 4
4

Data D D* BG

6

Data D D* BG

4

? B + D

2 Mmiss : EE C L < 0.2GeV

EE C L : 2 Mmiss > 2.0GeV2 /c4
Events / 0.4 GeV2/c
4

? B (B + D0 + ) = + .41 + .24 (1.51-0.39 -0.19 Б 0 0 3.8 signifi ? B (B + D0 + ) = + .69 + .40 (3.04-0.66 -0.47 Б 0 0 3.9 signifi

0.15)%, cance 0.22)%, cance

10 8 6 4

6

? B + D

+ .22 + .06 R(D- ) = 0.48-0.19 -0.05 0 0 + .14 + .06 R(D- ) = 0.48-0.12 -0.04 0 0

2 2 0 -2 0 0 2 4 6 8 2 Mmiss (GeV2/c4) 0 0.25 0.5 0.75 1 ECL Eextra(GeV)

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BELLE

Constraint for 2HDM type II
()

? Combining results from B and B D charged Higgs model 2HDM type II. G On all figures prefered regions are different. G 2HDM type II is excluded?
G

we can constrain
Belle B



R(D)

0.8 0.6 0.4 0.2

BaBar ? B D() ' c
0.2 0.4


theory

Belle ? B D() c c T
1



measurement

R(D*)

0 0.4 0.3 0.2 0

T

0.6

0.8

c T
0.2 0.4

c T

tan /mH + (GeV

0.6 -1

0.8

1

)

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BELLE

? B D() and SM
SM R(D) = 0.297 Б 0.017 R(D ) = 0.252 Б 0.003 Belle R(D) = 0.430 Б 0.091 R(D ) = 0.405 Б 0.047 Combined Deviation 2.0 2.7 3.4 Deviation 1.4 3.0 3.3

PRD 85, 094025 (2012)

PRL 109, 101802 (2012)

BaBar R(D) = 0.440 Б 0.058 Б 0.042 R(D ) = 0.332 Б 0.024 Б 0.018 Combined Belle & BaBar R(D) R(D ) Combined Deviation 2.4 3.8 4.8

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BELLE

Summary
B decay was studied at Belle with different tagging. Results are consistent with each other and BaBar result; Recent result is much closer to SM prediction, "tension" in CKM global fit is reduced; ? Results for B D() are consistent between tagging types and experiments; 2HDM type II seems to be excluded by combination of B and ? B D results; Results for R(D() ) are different from SM at 4.8 for combination of Belle and BaBar results.

G G G G G

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BELLE

Stay tuned for updated results and upcoming Belle II results.

Thank you!

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Dmitri Liventsev - B and related results - 22 / 23


BELLE

? Comparison of the B D() results

Good agreement between different tagging; G Good agreement with BaBar: ? B (B D ) = [1.76 Б 0.13 Б 0.12]% ? B (B D ) = [1.02 Б 0.13 Б 0.11]%; G All results are slightly larger than SM predictions.
G

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