Transcript Bファクトリーの成果とSuperKEKB

Bファクトリーの成果とSuper-B
Jan.19, 2005 ＠京都大学
山内正則
KEK
0
0
CP violation in B B system
Af =
| lf |2 - 1
Standard model predictions
| lf |2 + 1
Sf = -xf
lf ≡e-2ifM
2Im( lf )
| lf |2 + 1
A( Bgf )
A( Bgf )
Note: Af = 0 a G(Bgf ) = G(Bgf ) a direct CP violation.
The fi’s and CKM matrix
CKM quark mixing matrix
Unitarity
Unitarity triangle
f1≡p-arg(
f2≡arg(
-Vtb*Vtd
)
-Vcb* Vcd
Vtb*Vtd
* Vud
-Vub
)
Principle of the measurement

Large data sample
G(BgfCP;t ) can be measured.
Af and Sf
Old result of sin2f1
(Belle, Feb. 2002, hep-ex/0205020)
1550 events
441.8 fb-1
4 6 bgccs decay modes
(BgJ/yKS, J/yKL etc.)
4 Sccs = sin2f1
= 0.82±0.12±0.05
+0.08
4|lccs| = 1.01 -0.07 (stat.)
i.e., Accs is consistent
with 0.
KEKB Collider
Mt. Tsukuba
KEKB
Belle
~1 km in diameter
Lpeak = 1.39 x 1034 sec-1cm-2
@ 1.2A x 1.6A
253 fb-1 on Y(4S)
275M BB
~287 fb-1
28 fb-1 below Y(4S)
8 GeV e- x 3.5 GeV e+
11mrad crossing
Continuous Injection
No need to stop run
Always at ~max. currents, luminosity
~30% more  L dt
[CERN courier Jan/Feb 2004]
both KEKB & PEP-II
continuous injection (new)
normal injection (old)
HER current
LER current
Luminosity
0
~1 fb-1/day !
(~1x106 BB)
12
Time
24
Belle Collaboration
Aomori U.
BINP
Chiba U. ww w w
w
w
w
Chuo U.
U. of Cincinnati
Frankfurt U.
w
Gyeongsang Nat’l U.
w w
Hiroshima Tech.
IHEP, Beijing
ITEP
Kanagawa U.
KEK
Korea U.
Krakow Inst. of Nucl. Phys.
Kyoto U.
Kyungpook National U.
U. of Lausanne
Jozef Stefan Inst.
U. of Maribor
U. of Melbourne
Nagoya U.
Nara Women’s U.
National Central U.
w w ww
ww
Nat’l w
Kaoshiung
Normal U.
w
Nat’l
w Lien-Ho Inst. of Tech.
w
Nat’l Taiwan U.
Nihon Dental College
Niigata U.
Osaka U.
Osaka City U.
Panjab U.
w
w
Peking U.
Princeton U.
Riken
Saga U.
USTC
Seoul National U.
Sungkyunkwan U.
U. of Sydney
Tata Institute
w
w
w
Toho U.
Tohoku U.
Tohuku Gakuin U.
U. of Tokyo
Tokyo Inst. of Tech.
Tokyo Metropolitan U.
Tokyo U. of A and T.
Toyama Nat’l College
U. of Tsukuba
Utkal U.
IHEP, Vienna
VPI
Yokkaichi U.
Yonsei U.
Belle Detector
Aerogel Cherenkov cnt.
n=1.015~1.030
SC solenoid
1.5T
3.5GeV e+
CsI(Tl) 16X0
TOF counter
8GeV eTracking + dE/dx
small cell + He/C2H5
Si vtx. det.
3 lyr. DSSD
m / KL detection
14/15 lyr. RPC+Fe
Sub decay modes
cc1,cc2J/y
+g
J/y
m+m-
s=7.0
MeV/c2
s=9.6MeV
/c2
cc
1
J/y
e+e-(g)
cc
y’
2
s=10.7MeV
/c2
p0
sM=4.1 MeV/c2
Mll (GeV/c2) y’m+m,e+es=12.1
2
MeV/c
Mll
(GeV/c2)
M(KSp+p-)
(GeV/c2)
Mllg-Mll
(GeV/c2)
sM=9.3 MeV/c2
in inclusive J/y events
M(K p0p0) (GeV/c2)
sin2f1: charmonium K0
0
( cc ) K S (C P odd) m odes
Belle
BABAR
2003
bkg
Update for ICHEP04
sin 2   + 0 . 722  0.040  0.023
l  A / A  0.950  0.031  0.013
205 fb
-1
Belle CONF-0436
BABAR PUB-04/038
0
( cc ) K S +
0
( cc ) K L
on peak or 227 M BB pairs
7730 CP events (tagged signal)
sin 2   + 0 . 728  0.056  0.023
l  A / A  1.007  0.041  0.033
140 fb
-1
on peak or 152M BB pairs
4347 CP events (tagged signal)
Current Results for sin2f1
sin2f1 (2004 World Av.)
= 0.726±0.037
[LP2003: 0.736 ±0.049]
precision measurement
(~5%)
Good SM reference
B0 p+p- CPV Result
152M BB
App
Direct CPV
3.2s
good tag Dt (ps)
Spp
App = +0.58 0.15(stat) 0.07(syst)
Spp = -1.00 0.21(stat) 0.07(syst)
[PRL93,021801
(2004)]
History of App and Spp
B0 p+pTCPV
Difference
at ~3.1s level
(was ~2.2s)
Belle
227MBB
New
BaBar
Direct CPV: B  Kp

Vus/d
b
B
0
d
d
_ _
s/d
W
u
Vub
u
d
K/p+
p-
b
B 0d
d
Vtb
W
t

Vts/d
g
s/d
+
K/p
u
u
d
p-
Tree
Penguin
• Simplest charmless rare decay modes
• Tree - Penguin interference  Direct CP Violation
_ _
Key prediction of
Kobayashi-Maskawa model
Observation in B
G(B f ) - G(B f )
_ _
ACP =
G(B f ) + G(B f )
Strong support of KM
274M BB
New
0
+
ACP(B  K p )
_
B0 K-p+
B0 K+p-
Signal:
2139 53
[submitted to PRL]
ACP = -0.101  0.025  0.005
3.9s significance
[PID efficiency bias correction: dA = -0.01  0.004]
2nd Evidence for DCPV at Belle ! [A(p+p-) 3.2s]
ACP(B0  K+p-)
hep-ex/0408057,
submitted to PRL
227M BB
Signal (227 M BB pairs): 1606  51
+
BABAR B 0  K -p
B  K p
0
4.2s
AC P  - 0.133  0.030  0.009
Average of Belle and BaBar
AC P  - 0.114  0.020 > 5s
First established Direct CPV in B decays !
+
ACP(B  K+p0 )
274M BB
New
Kp0 : 728 53
ACP(Kp0 ) = 0.04  0.05  0.02
0.06  0.06  0.06 (BaBar, 227M)
AC P  + 0.049  0.040
hint that ACP(K+p- )  ACP(Kp0 ) ? (3.6s)
Average
Large EW penguin
New Physics ?
(Z0)
?
B-
d
_
d
b
s
u
u
p0
K-
New physics Search : b  sqq
b
_
B0
d
t
s f
s
s
d KS
B0 fKs
b
+
d
X
s f
s
s K
d S
68 ev
“sin2f1”=
-0.96  0.51
Belle @LP03
3.5s deviation
from the SM !
B0  f K0
274M BB
fKS
Nsig=139 14
purity 0.63
fKL
Nsig= 36 15
purity 0.17
pB*
includes Ks  p0po
(Nsig=13 5)
Similar to J/yKL recon.
+ sophisticated continuum
suppression
B0  f K0 : CPV Result
f K0
S = 0.736
fit
Good tags
Poor tags
Good tags
fKS + fKL : S (fK0) = +0.06  0.33  0.09
A (fK0) = +0.08  0.22  0.09
~2.2s away from SM
274M BB
B0h’KS
h’KS
high statistics modes
Raw Asymmetry
Nsig=512 27
purity 0.61
BABAR
h’ rg,
hp+p(h gg,
p+p-p0)
+
0
S = 0.736
fit
Good tags
B  h K S
0
0
Signal: 819  38
 sin 2  [ cc ] @ 3.0s
(~0.5s @SM)
S = +0.65 0.18 0.04
A = -0.19 0.11 0.05
274M BB
-
h   r g ,h p p
+
0
h  gg , p p p
0
+
0
0
K S  p p ,p p
-h C P  S h K 0  + 0 . 27  0.14  0.03
S
C h K 0  - 0 . 21  0.10  0 . 03
S
208 M BB pairs
Averages for sin2 and s-penguin modes
3.6s from s-penguin
to sin2b (cc)
No sign of Direct CP in averages
Radiative & EW Penguins
Loops  Sensitive to New Physics
l+
l-
aEW
b  sl+l- penguin
~1/100
b  sg penguin
Br, ACP ~SM
K*g TCPV
b  dg penguin
B  K(*) l+lLP03: B  Xsll, K(*)ll : first observed by Belle, confirmed by BaBar
Br, ACP ~SM
274M BB update >10s signals
B
B
(Kll)= (5.50  0.75
0.70  0.27  0.02)
(K*ll)= (16.5  2.3
2.2  0.9  0.4 )
x 10-7
79 10
signals
82 11
signals
[Belle-conf-0415]
B  K* l+l- :FB Asymmetry
274M BB
AFB(K*ll ) : very sensitive to NP
that may not be seen in B(bsg)
AF B 
G ( B l +  p / 2) - G ( B l +  p / 2)
G ( B l +  p / 2) + G ( B l +  p / 2)
raw AFB
q2
K*
First Look !
2
q
[Belle-conf-0415]
Road Map of B Physics
sin2f1, CPV in Bgpp,
f3, Vub, Vcb, bgsg,
bgsll, new states etc.
Yes!!
Anomalous
CPV in bgsss
Identification of SUSY
breaking mechanism
if NP=SUSY
Study of NP effect
in B and t decays
Precise test of SM
and search for NP
NP discovered
at LHC(2010?)
Discovery of CPV
in B decays
Now
340 fb-1
Physics Program at Super-B
New CPV phase
FCNC decays
B  f K , h  K , ...
0
0
B  X Sg
B  K g , X Sg
*
B K
(*)
,XS
Precision CKM
sin 2f1 ( B  J / y K )
0
LFV decays
t  g
t 
, h
sin 2f 2 ( B  pp , rp , rr )
f3 ( B  D K )
| V ub ( cb ) | ( B  X u ( c )  )
Higgs Search
B  t
B  D t
(*)
Global Analysis of
B Physics
(Study of New Physics Scenario)
Investigating SUSY in flavor physics
Mass+mixing angle+phase
• MSSM parameters > 100 !
• The squark/slepton mass matrix
– Sensitive to SUSY breaking mechanism.
Baryon asymmetry ?
– New sources of flavor mixing
 mq
2
)

ij
m
2
11
m
2
21
m
2
31
m
2
12
m
2
22
m
2
32
m
2
13
m
2
23
m
2
33
Off-diagonal terms
Flavor Physics
Luminosity frontier
qi
qj
qDiagonal
terms:
i
2
LHC/ILC
(m q )2 3 (1 3 )
Energy frontier
Physics at Super-B = SUSY Flavor Physics
Its importance is independent of LHC results.
(VCKM could not be pin down only with energy frontier)
qj
Super-KEKB
Lpeak (cm-2s-1)
Lint
1.4x1034
280 fb-1
Projection of
KEKB luminosity
5x1034
1 ab-1
Super-KEKB
(major upgrade)
Taget Luminosity
5x1035 cm-2s-1
Crab cavity
5x1035
10 ab-1
5x109 BB
/year !!
& also t+t-
Expected Precision
Statistical significance w/
the present central value
Expectation atMode
5ab-1 DS error
KS0
fK0 (input S=+0.24)fK0 J/y0.079
0.049
h’K0
K+K-K0 0.056
Signif.
4.9
6.4
3.5
DS theory error
fK0: ~0.05
h’K0: ~0.10
Pattern of the deviation from the SM prediction
Unitarity triangle
Bdunitarity
mSUGRA
SU(5)SUSY
GUT + R
Rare decay
D m(Bs)
e
B->fKs
B->Msg
Y.Okada
b->sg
indirect CP direct CP
-
-
-
-
-
+
-
+
+
-
+
-
(degenerate)
SU(5)SUSY
GUT + R
(nondegenerate)
U(2) Flavor
symmetry
-
-
+
++
++
+
+
+
++
++
+
++
++: Large, +: sizable, -: small
Acp(BfKs) vs SUSY models
280fb-1
Acpmix
5ab-1
mSUGURA
tan=30
SU(5)+R
tan=30
degenerate
U(2)
tan=30
SU(5)+R
tan=30
non-degenerate
m g ( G eV )
50ab-1
Acpが比較的小さけ
れば早期にズレは
はっきりする。
その場合、
M(gluino)~500GeV
を示唆する。
Acp(BXsg) vs SUSY models
5ab-1
50ab-1
Mixing CPV
U(2)
tan=30
mSUGURA
tan=30
Acpmix
Acpdir
Direct CPV
mSUGURA
tan=30
SU(5)+R
tan=30
SU(5)+R
tan=30
degenerate
SU(5)+R
tan=30
non-degenerate
degenerate
m g ( G eV )
U(2)
tan=30
SU(5)+R
tan=30
non-degenerate
m g ( G eV )
5ab-1 ではM(gluino)=1TeV, 50ab-1では2TeVまで攻める。
FB asymmetry in bsl+l• Sensitive probe for NP
(theoretically clean)
*
eff
A F B    C 10 ( sC 9 ( s ) + r ( s ) C 7 ) 
Br(BXsg), D0+(BK*g)
+
-
B
B
-
+
C7 < 0
2
C
NP
10
SM(0,0)
SM
1
AF B
3
3
Bound from
present Br(Xsl+l-)
2
1
NP
C9
SUSY Scan (MFV)
sˆ
FB asymmetry in bsl+l- (cont’d)
• Present status (250fb-1)
• At Super-B
どこで Zero-cross するか？
MC (5ab-1)
MC (50ab-1)
Identify rough pattern
(sign flip bet. low q2/high q2)
dC9~10%, dC10~14%
まで制限可能
PID（m/p ）も重要。
Branching fraction のdilepton mass 分布の測定も有効。
Full reconstruction
• 片側のB中間子を完全再構成して反対側のB崩壊をtagする。
• 特に、, t を含む崩壊の精密測定や探索に威力。e+e- B factory でのみ可能。
“オフラインB中間子ビーム”
運動量、電荷、フレーバー既知
e- (8GeV)
B
Υ(4S)
e+(3.5GeV)
B
• B Dt: 12 s observation
at 5 ab-1.
• BK: 5 s observation
at 50ab-1.
Interesting decays
•B → ul
•B → t, K
•B → Dt
•etc
p
full tagging
Charged Higgs 探索
m b tan  + m c ( u ) cot 
• Bt (leptonic decay)
b
G(B   ) 
rH  1 - tan 
2
2
F
2
G mBm f
8p
2
B
2
m
mH 
Present status
2
B

m 
1
 rH

2 
mB 

mt tan 
t
2
Vub
2
u
H+/W+
M  mt tan 
2
t+
Charged Higgs 探索
• BDt (semileptonic decay)
B
G ( B  Dt vt )
G ( B  D m vm )
m b tan  + m c ( u ) cot 
バンド幅：Form-factor
による不定性
c
b
H+/W+
mt tan 
t+
t
• Signal  large missing mass
• Expected at 5ab-1
Mode
Nsig
0 +
+
D t (  t ) t 280
+
+
D t ( h  t ) t
0
620
Nbkg dB/B
550
3600
7.9%
Sensitivity for charged Higgs
BXs g による制限
LHC
100fb-1
BDt
現在のBt
による制限
D(form-factor)は
現在のBDm
データで測定可能
LHCとの先陣争い。
Lepton Flavor Violation
LFV in neutrino sector already seen (at maximal mixing).
⇒LFV in charged leptons ?
Tau lepton
• The heaviest lepton
• 3rd generation
Enhancement in the rate
ex.) Br(tmg)~104-5 x Br(meg)
Both 32(m)/31(e) transition can be
explored ⇒slepton flavor structure.
B-factory = “Tau-factory”
• s(tt) ~ s(BB)
• 5x109 t pairs at 5ab-1
Rare decay sensitivity at O(10-9)
tmg measurements
• Present Belle results (86fb-1, 7.9x107 t-pairs)
Expected signal
– Br(tmg) < 3.1 x 10-7 (90%CL)
distribution
– Br(teg) < 3.8 x 10-7 (90%CL)
g
Belle
(tmg)
Background
mmg
Mis-id (mp)
ttg generic
Escape from
missing mass cut
Improvement
• Analysis (selection criteria, cut analysis likelihood analysis)
• Particle ID (better rejection of mp fake)
• g energy resolution
Tau LFV search (pastfuture)
w/ improvement
tlg
tlp/h/h’
Extrapolation
Expected sensitivity
for t→mg
Simple extrapolation
from the present
t3l
tl Ks
tB g/p
w/ improvement
Search region enters into O(10-810-9)
tmg/eg
g
• SUSY + Seasaw
– Flavor violation by -Yukawa coupling.
– Large LFV
Br(tmg)=O(10-7~9)
B r (t  mg )
 m2 )
L 32
-6
10  
 m L2

Present Belle
  1 T eV  4
2

 ta n 
  m SU SY 

Super-B
tanβ = 30, A0 = 0, μ > 0
Gaugino mass = 200GeV
c0
t
t
m (e)
m (e )
2
(m l )2 3 (1 3 )
Similar for eg case
探索可能な領域
(max.  m )
2
L
32
)
tmg in SUSY GUT
SU(5) GUT+R
Squark/slepton mass matrix relation

2
md
R
)
23

 ml
2
L
)
e
i(φ 2 - φ 3 )
23
Correlation to Acpmix(BXsg) and Acpmix(BfKs)
m0
mg
These correlations provides non-trivial test of SUSY GUT
CKM fit
|Vub|
• Determine (r,h) only by tree
processes (SM dominant).
– |Vub| from bgul
f3 from BgDK
– f3 from BgDK
• Compare it with (r,h) determined through
– |Vtd| from BB mixing, i.e. DMd
– f1 from BJ/yKS
• This gives M12=M12SM+M12NP
|Vtd|
f1 from BJ/yKS
UT at Super-B
5
ab-1
D sin 2f1  0.019
D( fB
B d )  0.011  0.026
50
ab-1
D sin 2f1  0.014
D( fB
B d )  0.005  0.015
D | V u b | 5.8%
D | V ub | 4.4%
D f3  4
D f 3  1.2
Vub & f3
sin2f1 & Dmd
Vub & f3
sin2f1 & Dmd
UT vs SUSY models
Dm(Bs)/Dm(Bd)
5ab-1
50ab-1
mSUGRA
tan=30
SU(5)+R
tan=30
degenerate
U(2)
tan=30
SU(5)+R
tan=30
non-degenerate
f3 (degree)
Summary-1
• New CPV phase の発見可能性
– 中心値による
– 5ab-1 で可能（2012年頃？）
– Bsss 平均については1ab-1でも可（2007年）
“ずれ”>5sとなる領域
5ab-1
1ab-1
fKS
S
K+K-KS
h’KS
bsss
K*g
50ab-1
SM
Summary-2
2010
2005
1ab-1 SuperKEKB
KEKB
Discovery phase
New
CPV
phase
bsss
K*g
LFV
tlg,lh.lll
claim
2015
5ab-1
10ab-1
50ab-1 へ
Investigation phase
fKs, h’Ks
SU(5), mSUGRA?
Acp<0 or 小 なら早期発見もありうる。Study of NP scenario
M(gluino)~500GeVを示唆
2TeVまで可能。
Global B Analysis
~5x10-8
決着
~1x10-8
~5x10-9
発見の可能性大。
発見なら精密測定を目指す（検出器改良）。
Charged Higgs
BDt
発見の可能性はある（tan 大）。
LHCが100fb-1貯める前に逃げ切る。
LHC
確認
MSUSY 小
MSUSY 大
見つからない？
結論
Discovery:
Super-B は、ループ効果による新粒子探索のフロンティア
New Physics の間接発見をできる可能性は十分にある。
Investigation:
Super-B で、種々のフレーバー遷移過程を測定することに
よって、New Physics scenario の検証が可能。
2009年前後に Super-B へのアップグレードを行えば、上記の
ような研究をLHC実験と同時期にできる。
Super-Bの物理の重要性はLHC/ILCと補完的。LHCでSUSYが
見つからない（或いは重い）場合、Super-Bの物理はさらに重要。
FCNC＋LFV
Super-KEKB upgrades
Interaction region
Crab crossing
 = 30 mrad
y* = 3 mm
New QCS
New beam pipe
Ante-chamber & solenoid coils
for reduction of electron cloud
Linac upgrade
More rf power
Damping ring
LOI (Jan 04) for SuperKEKB
[http://belle.kek.jp/superb/]
HEP Scenario in Japan
J-PARC 1 construction
Construct.
fund
ILC construction
T2K
SuperKEKB const.
Operation
fund
Crab cavity
KEKB
machine
“Minor” upgrade
Belle
2004
05
SuperKEKB
1000fb-1
KEKB
06
07
08
“Major” upgrade
09
Calendar year
10
11
12
Possible Timeline for Super PEP Program
Super-B
Program
R&D, Design, Proposals Construct upgrades for
L = 5-7x1035
and Approvals
Super B
Operation
-1
 Ld t ~ 10 ab / yr
2001
2003
2005 2006
2008
2010 2011 2012
Construction
Installation
LOI CDR
P5
Commission
Planned PEP-II Program
 Ld t  14 0 fb
-1
(June 30, 2003)
 Ld t  5 0 0 f b
(End 2006)
-1
 Ld t ~ 1 - 2 ab
(PEP-II ultimate)
-1
結論とまとめ

Bファクトリーはこれまで．．．







この延長としてSuper-Bを提案






B中間子におけるCPVの発見、精密測定
ユニタリティ三角形の決定
直接的CPVの発見
ｂｓペンギンにおける異常CPV：新しい物理？
新しい共鳴の発見、４-quark？
Bの稀崩壊の系統的研究
異常CPVの確立と精密測定
ｂsl+l-などの測定によるループの直接測定
CKMの精密な決定
LFV、H±の探索
．．．などによって、新しいフレーバー混合とCPVを解明
SLACと協調し、新たな実験グループの創設へ
ILCと干渉しない国内計画として適正規模