Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://nuclphys.sinp.msu.ru/b/old/Belle_ICHEP04.pdf Äàòà èçìåíåíèÿ: Fri Apr 22 14:45:55 2005 Äàòà èíäåêñèðîâàíèÿ: Tue Oct 2 00:33:31 2012 Êîäèðîâêà:

Recent Results on B decays
- Rare B Decay Highlights + Belle b sqq Time-dependent CPV [Includes updates/corrections after ICHEP04 talk]

Y.Sakai (Belle/KEK)
ICHEP 2004, Beijing 1


Outline
Introduction KEKB and Belle Detector [PEP-II/BaBar: by Giorgi] New Results on Rare decays (Belle/BaBar) (Highlights) Updated/New results on b s TCPV from Belle
[Results are preliminary unless references are given] Apology; cannot cover all of the many interesting results from the parallel sessions Contributed papers available Belle: http://belle.kek.jp/conferences/ICHEP2004/ BaBar: http://www.slac.stanford.edu/BFROOT/ www/Public/ichep2004/
ICHEP 2004, Beijing 2


B Decays & the SM
Quark level Electro-weak Hadrons Final state
* Vud Vub () 2 * Vtd Vtb



3()



* Vcd Vcb

1()

QCD/Lattice QCD/Lattice New Resonances New Resonances b-quark: Heavy variety of decay modes Rich field for fundamental SM parameters
ICHEP 2004, Beijing 3


B decays & New Physics
Experimental measurements New Physics ? New Physics ? agree? No SM predictions Yes Deeper understanding Deeper understanding

Key point: ANP ~ ASM (small/forbidden) Penguin W

b

t

s,d
g,,Z

+

b

x

s,d
4

New particle, Phase
ICHEP 2004, Beijing


KEKB Collider
Mt. Tsukuba

8 GeV e- x 3.5 GeV e+
±11mrad crossing
Energy High Electron for (LER)
TSUKUBA Area (Belle)

KEKB

Belle
Ring Low for Energy Positron

HER LER Interaction Region

Ring (HER)

WIGGLER

WIGGLER

RF

NIKKO Area

Lpeak = 1.39 x 1034 sec-1cm-2 @ 1.2A x 1.6A -1

RF

(TRISTAN Accumulation Ring)

Electron

Positron

253 fb on Y(4S) 275M BB ~287 fb 28 fb-1 below Y(4S)

-1

RF RF FUJI Area

LER

HER

RF

RF
OHO Area

~1 km in diameter

ICHEP 2004, Beijing

e

+

/e

-

Linac

5


Continuous Injection
No need to stop run Always at ~max. currents, luminosity ~30% more L dt
normal injection (old)
[CERN courier Jan/Feb 2004] both KEKB & PEP-II

continuous injection (new) HER current LER current Luminosity
0 12

~1 fb-1/day ! (~1x106 BB)
Time
6

24

ICHEP 2004, Beijing


Belle Detector
SC solenoid
1.5T

Aerogel Cherenkov cnt.
n=1.015~1.030

CsI(Tl)
16X0

3.5 GeV e

+

TOF conter 8 GeV e
-

Central Drift Chamber
small cell +He/C2H5

Si vtx. det.
3(4) lyr. DSSD

µ / KL detection
ICHEP 2004, Beijing

14/15 lyr. RPC+Fe
7


SVD Upgrade

2003 summer

Impact parameter resolution

r
SVD1 SVD2

Z

· · · ·

1 MRad >20 MRad 3 layers 4 layers 23º<<139º 17º<<150º Rbp = 2.0 cm 1.5 cm Better I.P. resolutions

_ _ 152M BB pairs with SVD1 + 123M BB pairs with SVD2
ICHEP 2004, Beijing 8


B-meson Reconstruction
Utilize special Kinematics at Y(4S)

Energy difference:

E Ei - ECM 2 Beam-constrained mass:
M bc = ( E
(ES)

CM

2) - (
2



r pi )

2

ICHEP 2004, Beijing

9


Continuum Suppression
Dominant Background for rare decays:

e

+e-

qq "continuum"
(~3x BB)

Continuum Jet-like

qq e
+

e

-

To suppress: use event shape variables
Other B

continuum

e

+

e

-

Y (4S) -


BB spherical
Signal B
ICHEP 2004, Beijing 10


B /
Vus/d

__

s/d u u d

b

W

/
-

+

b

V

W
tb

V
g

B

0 d

V

ub

B

0 d

t

ts/d

s/d u u d

/
-

+

Tree Penguin · Simplest charmless rare decay modes · Tree - Penguin interference Direct CP Violation __
Key prediction of Key prediction of Kobayashi-Maskawa model Kobayashi-Maskawa model A
CP

d

d

=

(B f ) - (B f ) __ (B f ) + (B f )

Understanding of Penguin

Anomaly (New Physics)
ICHEP 2004, Beijing 11


ACP(B0 K+-)
275M BB New

_ B0 K-+

B0 K+-

Signal: 2139 ±53
[submitted to PRL]

ACP = -0.101 ± 0.025 ± 0.005

3.9 significance

[PID efficiency bias correction: A = -0.01 ± 0.004] 2nd Evidence for DCPV at Belle ! [A(+-) 3.2]
ICHEP 2004, Beijing 12


B0
152M BB

+- CPV Result

A



Direct CPV 3.2
good tag t (ps)

S
[PRL93,021801 (2004)]
13

A = +0.58 ±0.15(stat) ±0.07(syst) S = -1.00 ±0.21(stat) ±0.07(syst)

ICHEP 2004, Beijing


ACP(B K+0 )
275M BB New K±0 : 728 ±53

ACP(K±0 ) = 0.04 ± 0.05 ± 0.02 hint that ACP(K+- ) ACP(K±0 ) ? (2.4) Large EW penguin New Physics ? (Z0 )?
B- b u

[also seen by BaBar]

d _ d s u



0

K-
14

ICHEP 2004, Beijing


Observation of B0 00
275M BB, New

Key mode for 2() in B CPV isospin analysis



Evidence (LP03) Observation !

Signal: 82 ± 16 (6.0) B = (2.32 ±0.44 ±0.22 ) x 10-6 0.48 0.18 Large Br established
[Belle-conf-0406] Mbc

ACP = 0.44 ± 0.51 ±

0.17 0.16

uses same Flavor-tagging as TCPV analysis 1st measurement ! BaBar results & 2() Giorgi's talk
ICHEP 2004, Beijing 15


B0
224M BB

B0 00
N
sig

= 23 ±

B = (1.19

x 10-6 "pure b d Penguin"
+

7.7 ±2.0 (4.5) 6.7 ± 0.40 ± 0.13) 0.35

B0 0
N
sig

= 41 ±14 ±3 (3.5) B = (1.46 ±0.50 ± 0.07) (<2.35) x 10-6

First signals for B0
ICHEP 2004, Beijing 16


B VV : Polarization Puzzle
NaÎve Factorization : Longitudinal fL = 1 ­ O(1/mb2) (BaBar/Belle) +-, +0, (0K+) : fL 1 Penguin Anomaly ? Tree dominated New physics effect ? fL(K*) ~ 0.5 K*(bsss) only ? Penguin only QCD penguin annihilation: O(1/mb2) O(1) f/ f// = 1 + O(1/mb) ? fL(+K0) < fL(K*) ?
b

Vtb

W

[+K0 : pure b s Penguin] s d

V
g

B

+ u

t

ts

[e.g. A.Kagan hep-ph/0405134]

s s s u


*+



*0 +
ICHEP 2004, Beijing 17

u

d u




+K0 Polarization
152M BB

-

Mbc

+,K0 mass region
2D(Mbc,E,) ML fit

E

peak: 6.3 signif.

Mbc, E signal region
simultaneous fit to ,K* masses

+mass

K0mass

+K0 : 26.6 ±8.7

(Stat. sig: 3.2)
[Belle-conf-0404]
ICHEP 2004, Beijing 18


+K0 Polarization
+ helicity K0 helicity
bkg (fixed) +K (fixed)

152M BB

-

Transverse Longitudinal 2D(,K* helicity) ML-fit
(Mbc, E, mass signal region)

(3.1 away from fL= 1 ) fL =0.50 ± 0.19 ± 0.05 0.07 B = (6.6 ± 2.2 ± 0.8 ) x 10-6

[Belle-conf-0404]
19

ICHEP 2004, Beijing


+K0 Polarization
89M BB [BaBar-conf-04/34]

-

ML fit to all distributions simultaneously 1st observation

Nsig = 141 ± 23 (>5) 24 fL =0.79 ± 0.08 ±0.04 ±0.02 B = (17.0 ± 2.9 ± 2.9 ±0.0 ) 1.9
A
CP

x 10-6 = -0.14 ± 0.17 ±0.04 Belle Belle

BaBar + BaBar + likely ff likely L

L

<1 <1

non-resonant contribution
ICHEP 2004, Beijing 20


B K* : New Physics Search
Transversity basis: Angular distribution PK*( tr, tr, K* ; A0, A//, A )
2 sets_ (B, B) (12-1 parameters) _ _ Direct CPV = f= (|A|2+ |A|2_ )/2, = (|A|2- |A|2)/2 _ _ _ i = -Im(AAi*+AAi*), i = -Im(AAi*-AAi*) Triple-prod. __ __ (T-violation) *+A A *), = Re(A A *-A A *) //0 = Re(A//A0 // 0 //0 // 0 // 0
(i = 0, //)

A0 : longitudinal (CP= +1) A// : transverse CP= +1 A : transverse CP= -1

( |A0|2+ |A//|2 + |A|2 =1 )

"0" NP

[e.g. London, Sinha2, PRD69,114013(04)]
ICHEP 2004, Beijing 21


152M BB

-

B K*
[Belle-conf-0419]

97 ± 12 11 signals

K*0

fL =0.51 ± 0.06 ±0.04
confirm low f
L

46 ± 9 8 signals

K*+

ICHEP 2004, Beijing

22


B K* : New Physics Search
152M BB

-

f/ f// ~ 1 Triple product (T-conserving)
FSI

"0" NP

Triple product (T-violating)
[Belle-conf-0419]
ICHEP 2004, Beijing 23


B K* : New Physics Summary
arg(A// /A0 ) 2.34 ±0.23 ±0.05 (-2.34) BaBar/Belle -2.21 ±0.22 ±0.05 consistent arg(A /A0 ) 2.47 ±0.25 ±0.05 (0.67) "0" 0.64 ±0.21 ±0.06

BaBar (227M) Belle (152M)
* *

NP

No indication of NP except fL puzzle

(* recalculated from fit values)
ICHEP 2004, Beijing 24


Radiative

&

EW Penguins
l+ l-

Loops Sensitive to New Physics


EW

b sl+l- penguin ~1/100 b s penguin Br, ACP ~SM K* TCPV
ICHEP 2004, Beijing 25

b d penguin


B K(*) l+l-
LP03: B Xsll, K(*)ll : Belle/BaBar Br, ACP ~SM 275M BB update >10 signals 79 ±10 signals

[Belle-conf-0415]

B (Kll)= (5.50 ± B (K*ll)= (16.5 ±

0.75 ± 0.70 2.3 2.2

0.27 ± 0.02) ± 0.9 ± 0.4 ) x 10-7

82 ±11 signals

Mbc

q2 (GeV2/c2)
ICHEP 2004, Beijing 26


B K* l+l- :FB Asymmetry
AFB(K*ll ) : very sensitive to NP
that may not be seen in B(bs)
AFB = ( (
Bl Bl
+ +

275M BB
< / 2) - ( < / 2) + ( > / 2) > / 2)

Bl Bl

+ +

raw AFB q K*
2

First Look !

q [Belle-conf-0415]

2
27

ICHEP 2004, Beijing


b d : B (,)
Suppress K* with PID and M(`K') cut
[Belle-conf-0401]

B(B(,)) = (0.72

± 0.27 )x 10-6 (1.9) [< 1.4 x 10-6 @90% CL]

+0.43 -0.39

275M BB

Simultaneous fit to 3 modes: (B(,)) = (B++) = 2(B00) = 2(B0)

B(B(,)) = (0.6 ± 0.3
± 0.1) x 10-6 (2.1) [< 1.2 x 10-6 @90% CL] 219M BB
[hep-ex/0408034]
ICHEP 2004, Beijing 28

|Vtd|/|Vts| [ A.Ali's talk]


- Penguin CPV b sqq
Belle @LP03 (140 fb-1)
B0Ks
[PRL 91, 261602 (2003)]

B0 J/Ks etc

"sin21"= -0.96 ± 0.51

sin21=0.728 ± 0.06

3.5 deviation from the SM !
ICHEP 2004, Beijing 29


Time-dependent CP Violation
B0
mixing

f B0

CP

=

B0 B0
Direct CPV

f

(TCPV)
CP

ACP (t) = S sin(mt) + A cos (mt)
Mixing induced CPV
b B0 d

Vtb Vts
t



W

s s

~ g



b

g

s d

+
Ks

B

0

( ~ + RR)23 bR ~ g sR
d

s s s d

'
Ks

d

SM: b s Penguin phase = J/KS (b c) Sbs =sin21, A=0

+ New Physics with New Phase Sbs sin21 , A can 0
ICHEP 2004, Beijing 30


B0 K0
275M BB

KS
Nsig=139 ±14 purity 0.63

KL
Nsig= 36 ±15 purity 0.17 Similar to J/KL recon. + sophisticated continuum suppression
ICHEP 2004, Beijing 31

pB*

includes Ks 0 (Nsig=13 ±5)


B0 K0 : CPV Result
K0
S = 0.73 fit Good tags

Poor tags

Good tags

KSS+ KL :: S ((K00)) = +0.06 ± 0.33 ± 0.09 K + KL S K = +0.06 ± 0.33 ± 0.09 A ((K0) = +0.08 ± 0.22 ± 0.09 K0) = +0.08 ± 0.22 ± 0.09 A
~2 away from SM ~2 away from SM

275M BB

ICHEP 2004, Beijing

32


Checks: sin21 (B0 J/ KS/L)
Validation of new data sample (SVD2)
SVD1 Good tags

_ SVD1: 152M BB S = 0.696 ± 0.061 (stat) S = 0.696 ± 0.061 (stat) A = 0.011 ± 0.043 (stat) A = 0.011 ± 0.043 (stat) _ SVD2: 123M BB

SVD2 Good tags t (ps)
SVD1: S = -0.68 ± 0.46 A = -0.02 ± 0.28

S = 0.629 ± 0.069 (stat) S = 0.629 ± 0.069 (stat) A = 0.035 ± 0.044 (stat) A = 0.035 ± 0.044 (stat)
many systematic checks, all ok
ICHEP 2004, Beijing 33

K0

~2.3


SVD2: S = +0.78 ± 0.45 A =+0.17 ± 0.33


B0'KS & K+K-KS
'KS
high statistics modes ' , +- ( , +-0)

K+K-KS ( excluded)
Nsig=399 ±28 purity 0.56

Nsig=512 ±27 purity 0.61

Raw Asymmetry

Raw Asymmetry

S = 0.73 fit

CP=+1: 1.03 ±0.15 ±0.05

Good tags

Good tags

(~0.5 @SM) (~1.0 @SM) "sin21" S = +0.65 ±0.18 ±0.04 -S = +0.49 ±0.18 ±0.04 (± A = -0.19 ±0.11 ±0.05 A = -0.08 ±0.12 ±0.07

0.17 0.0

)
34

275M BB

ICHEP 2004, Beijing


KS

B0KS & f0(980)KS
additional modes f0(980)KS Nsig=94 ±14 purity 0.53 275M BB

Nsig=31 ±7

Raw Asymmetry

Good tags

Raw Asymmetry

purity 0.56

S = 0.73 fit

Good tags

(~0 @SM) "sin21" S = +0.75 ±0.64 ± 0.13 0.16 A = +0.26 ±0.48 ±0.15

-S = -0.47 ±0.41 ±0.08 A = -0.39 ±0.27 ±0.08

(~2.9 @SM)

ICHEP 2004, Beijing

35


B0 Ks0
Vertexing by Ks only
B vertex IP profile Ks track

+ -

Nsig=168 ±18 purity 0.55

Ks0

Validated by J/ Ks (use Ks only)
Raw Asymmetry



(+low purity: Nsig=83(0.17)) S = 0.73 fit

"sin21" S = +0.30 ±0.59 ±0.11 A = -0.12 ±0.20 ±0.07
275M BB

(~0.7 @SM)

Good tags

ICHEP 2004, Beijing

36


- CPV Summary of b sqq
"sin21"
275M BB

2.4
(A: consistent with 0)
ICHEP 2004, Beijing 37


B K* TCPV: New Physics
SM: polarized 0 & B0 opposite B S 2(ms/mb)sin 21 4% A ~ 1% New Physics Large S, A
[e.g. Atwood,Gronau,Soni]

B0

K*[Ks
0]


B vertex

Ks track

+ -

IP profile

Analysis Technique: similar to B0 Ks0


38

ICHEP 2004, Beijing


B K*[Ks0] TCPV
124M

BB

[hep-ex/0405082]

Nsig=57 ±9 purity 0.65

275M BB

S=0 fit

Nsig=105 ±14

S = +0.25 ±0.63 ±0.14 A = +0.57 ±0.32 ±0.09 = -C

First step for new era of b s !

S = -0.79 ± 0.63 ±0.09 0.50 A = -0.00 ±0.38
ICHEP 2004, Beijing 39


Summary
B decays: many new results from BaBar/Belle - Evidence for Direct CPV, ACP(K+-) ACP(K+0) ?
- B 00 decay established, 1st measurement of ACP(00) - fL(K*) Polarization Puzzle: fL(+K*0) < 1 No hint of T-violating NP in B K* - A first look at B K*ll FB-asymmetry - 1st B0 K*[Ks0] TCPV measurements

Belle b sqq TCPV updates - S (K0) = +0.06 ± 0.33 ± 0.09 (~2 away from SM) - average of b sqq : +0.43 ± 0.13 (~2.4 from SM) 0.11

(Giorgi's review for BaBar results)

More data needed to conclusively establish New Physics
ICHEP 2004, Beijing 40


Charmless B Br Summary

HFAG
P.Chang (NTU) J.Alexander (Cornell) J.Smith (Colorado) x10
ICHEP 2004, Beijing

Complete list (other Br & ACP ) http://www.slac.stanford.edu/xorg/hfag/rare/

-6

41


Backup

ICHEP 2004, Beijing

42


B PP/PV/VV Summary
+ 0 ' + 0 + 0 + 0
-

0 ' - 0



-

0

-

0

observed (>5) evidence (>3) upper limit Both, BaBar, Belle, CLEO DCPV: evidence in +-/+- only [extend to decays into scalar, axial-vector]
ICHEP 2004, Beijing 43


B0 KS : Mass & Helicity
Mass Helicity

bkg

ICHEP 2004, Beijing

44


B0 K0 : SVD1,2
SVD1 only SVD2 only

SVD1: S = -0.68 ± 0.46 A = -0.02 ± 0.28

~2.3


SVD2: S = +0.78 ± 0.45 A =+0.17 ± 0.33

many systematic checks, all ok
ICHEP 2004, Beijing 45


B0 KS, KL : CPV
KS only KL only

S = +0.00 ± 0.33 S = +0.00 ± 0.33 A = +0.06 ± 0.22 A = +0.06 ± 0.22

-S= +2.3 ± 2.0 -S= +2.3 ± 2.0 A = +0.6 ±1.2 A = +0.6 ±1.2

ICHEP 2004, Beijing

46


B0 K± : Validations
Control sample
Lifetime fit w/ B K± /KS B K± B K
S

Asymmetry fit w/ K±



B+

= 1.67

+0.12 ­0.11



B0

= 1.59

+0.20 ­0.19

S(K±) = ­0.03 ±0.20 A(K±) = +0.22 ±0.15
ICHEP 2004, Beijing 47


Systematic errors on S
Ks VTX flavor tag resolution fit bias signal fraction physics parameters background t shape tag side interference TOTAL 0.02 0.01 0.05 0.03 0.07 0.02 0.04 <0.01 0.11
0

K* 0.06 0.02 0.05 0.03 0.02 0.01 0.03 <0.01 0.10

Ks 0.01 0.04 0.07 +0.01 -0.10 0.10 0.01 0.02 0.01 +0.13 -0.16

' K s 0.01 0.01 0.03 0.01 0.02 <0.01 <0.01 <0.01 0.04

f0 Ks 0.02 0.01 0.03 0.03 0.05 0.01 0.04 <0.01 0.08

K

0

K+K-Ks 0.01 <0.01 0.03 0.01 0.02 <0.01 <0.01 <0.01 0.04
48

0.01 0.01 0.04 0.01 +0.08 -0.06 <0.01 0.01 <0.01 0.09

KKKS: effective sin21

0.17 for CP-even fraction

ICHEP 2004, Beijing


SVD2: lifetime & md

B
0

SVD2 only

D0+, J/ K± , D­+, D*­+/+, D*l
Belle preliminary

SVD1 _ (152M BB)

SVD2 _ (123M BB) (stat)



B

+



[ps]

B

0

1.534 ± 0.008 ± 0.010 1.518 ± 0 .0 12 1.635 ± 0.011 ± 0.011 1.652 ± 0 .0 14

[ps]

B

+

(stat)

md 0.511 ± 0.005 ± 0.006 0.516 ± 0 .0 07
[ps-1]

(stat)

md

[Belle-conf-0436]

New detector resolution is well understood
ICHEP 2004, Beijing 49


- CPV History of b sqq

ICHEP 2004, Beijing

50


f0(980)KS :+- Mass didtribution
fx

Non-f0 components are determined from the M(+-) distribution

[

f(f0KS) = 91% f(+-KS) = 2.3% f(0KS) = 4.8% f(fxKS) = 1.6%
ICHEP 2004, Beijing 51


Continuum Suppression
Event-shape variables combine Fisher Belle: cut on Likelihood Ratio LS/(Ls + LB ) BaBar: loose cut Fisher (or NN) pdf in fit
Flavor tagging info. also useful
ICHEP 2004, Beijing 52

signal

continuum
Fisher

signal continuum


CKM Matrix & UT
d ' s' b' VudVusVub = VcdVcsVcb V V V td ts tb d CKM matrix Complex phase s CP violation b (,)
* Vud Vub () 2

Unitarity triangle Vtd Vtb*

Wolfenstein representation

1-2 / 2 A3( -i) A2 - 1-2 / 2 A3(1- -i) - A2 1


(0,0)

3()

1() (0,1) * Vcd Vcb
53



ICHEP 2004, Beijing


BaBar B K*
use helicity basis angles: Angular distribution PK*( 1,2 , ; A0, A//, A )
_ 2 sets (B, B) 227M BB

B0 K*0 201 signals
ACP = -0.01 ± 0.09 ± 0.02
[hep-ex/0408017] cos1 cos2
ICHEP 2004, Beijing 54