New Physics in Rare Decays at Belle
Toru Iijima
Nagoya University
March 4, 2006KEK Theory Meeting 2006
“Particle Physics Phenomenology”
2
Conclusion
No New Physics Indication Yet in Rare Decays ! (except for some puzzles)
How significant is this fact ?
Many peoples expect NP at TeV.
3
Search for New Physics in 3rd Gen. Quark (B) and Lepton () Decays
Hadronic Penguin decayssome puzzles ?
Radiative decays
Electroweak decays
Tauonic decays
Tau decays Lepton flavor violation
Talk Outline
, .b s d etc
, .b c etc
.etc
Figure by Dr.Hayasaka (Nagoya Univ.)
, .b s s etc
At present and future (Super-B)
4
Pattern of B Decays B meson is the heaviest meson in the 3rd generation and
its decay has several patterns.– Large b quark mass– Huge top mass– Small Vcb– Non-zero Vub
B meson is an unique lab. To explore flavor mixing and CP violation. 1, , 3
- Vcb, Vub, Vtd
Many loops - box and penguin
W exchange coupled to
b u
l
W
ubV
b s
b d
d bW W
t,c,u
t,c,u
b du
u
g
b s
, Z
t
W b s
W W
t
b c
W
b
u
W
5
Belle Detector7 sub-detectors for precise
– Vertexing, – Tracking, – Particle ID, – Calorimetry
6
Belle Collaboration
13 countries, 57 institutes, ~400 collaborators
IHEP, ViennaITEPKanagawa U.KEKKorea U.Krakow Inst. of Nucl. Phys.Kyoto U. Kyungpook Nat’l U. EPF Lausanne Jozef Stefan Inst. / U. of Ljubljana / U. of MariborU. of Melbourne
Aomori U.BINPChiba U.Chonnam Nat’l U.U. of CincinnatiEwha Womans U.Frankfurt U.Gyeongsang Nat’l U.U. of HawaiiHiroshima Tech.IHEP, BeijingIHEP, Moscow
Nagoya U.Nara Women’s U.National Central U.Nat’l Kaoshiung Normal U.National Taiwan U.National United U.Nihon Dental CollegeNiigata U.Osaka U.Osaka City U.Panjab U.Peking U.U. of PittsburghPrinceton U.RikenSaga U.USTC
Seoul National U.Shinshu U.Sungkyunkwan U.U. of SydneyTata InstituteToho U.Tohoku U.Tohuku Gakuin U.U. of TokyoTokyo Inst. of Tech.Tokyo Metropolitan U.Tokyo U. of Agri. and Tech.Toyama Nat’l CollegeU. of TsukubaUtkal U.VPIYonsei U.
7
e+ source
Ares RF cavity
Belle detectorSCC RF(HER)
ARES(LER)
The KEKB Collider e- (8.0GeV) × e+ (3.5GeV)
⇒(4S) →BB⇒Lorentz boost: = 0.425
Finite crossing angle- 11mrad ×2
Operation since 1999.
Peak luminosity 1.63 x 1034 cm-2s-1 !Integrated luminosity >560fb-1
8
KEKB PerformanceRecords as of Mar.1,’06 L peak = 1.63x1034cm-2s-1
L day = 1182.5pb-1/day L int = 563.3 (Mar 1,’06)
CESR
KEKB Lint/month
Record = 27.9fb-1
9
KEKB Upgrade Scenario
~1010 BB/year !!& similar number
of +-
Lpeak = 1.41034cm-2s-1
Ltot = 330fb-1 (Nov.30, 2004)
1.4x1034
330 fb-1
5x1034
~1 ab-1
5x1035
~10 ab-1
Lpeak (cm-2s-1)Lint
Crabcavities
Major upgrade ofKEKB & Belle detector(>1yr shutdown)
world records !
10
Rare Decay Milestone
Observation of BK l+ l-Large CP Violation in B
Observation of Large CPV and evidence of direct CPV in B+-
Beginning of B->K0 saga
Direct CPV in B0K+
Observation of bd
FB asymmetry in BK* l+l-
Successful operation of B factories has enabled us to–Measure the B decays in different patterns.–Measure not only branching fraction, but also more details
•CP asymmetry•B+/B0 difference•Distribution (Mx in bs, AFB in BK*ll)
Successful operation of B factories has enabled us to–Measure the B decays in different patterns.–Measure not only branching fraction, but also more details
•CP asymmetry•B+/B0 difference•Distribution (Mx in bs, AFB in BK*ll)
11
Direct CPV in BK Remarkable progress in the B-factory era.
CLEO w/ 2.6M BB: [PRD53,1039(1996)]
PID for high momentum K/.
386 x 106 BB
hep-ex/0507045
12
K puzzle ? Ratio of branching fraction Different sign of
Acp(K+-) and Acp(K+0).0
0
( )2 1.00 0.08
( )c
B B KR
B B K
0
0 0 0
1 ( )0.79 0.08
2 ( )n
B B KR
B B K
Possible reasons; Large EW-penguin (with large phase) Large color suppressed diagram ? Or both
NP (ex. Z’) ??
No conclusion yet.
13
Possible to search for NP in theoretically clean way.
Many observables;– Branching fractions– Mixing induced CPV– Direct CPV– Forward-backward asym.– Ratio of exclusive modes
bs/sl+l-
b s
t
W b s
, Z
t
W b s
W W
t
M(H+) > 350 GeV alreadyin TYPE II 2HDM
Effective Hamiltonian for bs10
*
1
4( ) ( )
2F
eff ts tb ii
GH V V C O
|C7| by BXs, Sign of C7, C9, C10 by BXsll
14
bs BK*, PRD69,112001 (2004)
– 85.0MBB
0 *0
*
0.0260 0.026
*
( ) 4.01 0.21 0.17
( ) 4.25 0.31 0.24
0.012 0.044
( ) 0.015 0.044 0.012CP
Br B K
Br B K
A K
0 *0
*
0.0260 0.026
*
( ) 4.01 0.21 0.17
( ) 4.25 0.31 0.24
0.012 0.044
( ) 0.015 0.044 0.012CP
Br B K
Br B K
A K
bs(inclusive) PRD93,061803 (2004)
– 152MBB
0.30 0.11 40.31 0.07
( )
(3.55 0.32 ) 10
Br b s
0.30 0.11 40.31 0.07
( )
(3.55 0.32 ) 10
Br b s
140fb-1
E > 1.8 GeV
(M.Nakao @ CKM2005)
15
bd 386M BB qq background suppression;
– Event shape– Decay vertex– Flavor tagging quality
Hep-ex/0506079v2BELLE preprint 2006-5Submitted to PRL
0.42 0.090.36 0.08( ) 0.55Br B
0 0 0.37 0.070.33 0.06( ) 1.25Br B
0 0.34 0.050.27 0.10( ) 0.56Br B
0.34 0.100.31 0.09( ( , ) ) 1.32Br B
w/ constraint from isospin relation
0.026 0.0180.025 0.0150.199 (exp.) ( .)td tsV V theo 0.026 0.0180.025 0.0150.199 (exp.) ( .)td tsV V theo
w/ Br(BK*)
16
Measurement of B(BXsl+l-)
Semi-inclusive technique– Xs is reconstructed from K+ or K
s + 0-4 (at most one 0 is allowed)
– MXs < 2.0 GeV
Electron or muon pair– Mll>0.2GeV– Charmonium veto
140/fb data
Theoretical prediction by Ali et al.
Wrong flavor
MXs q2
M. Iwasaki et al. submitted to PRD, hep-ex/0503044
17
C7 = -C7SM
Constraints on Ci from B(BXsl+l-)
Clean prediction for B(BXsll) with 1<q2<6GeV2 is available.– Combine Belle and Babar results– Sign of C7 flipped case with SM C9 and C10 value is unlikely.
P.Gambino, U.Haisch and M.Misiak PRL 94 061803 (2005)
BF Belle Babar WA SM C7 = -C7SM
q2>(2m)2 4.11±1.1 5.6±2.0 4.5±1.0 4.4±0.7 8.8±0.7
1<q2<6GeV2 1.5±0.6 1.8±0.9 1.60±0.5 1.57±0.16 3.30±0.25
C10NP C10
NP
C9NP
Donut : 90% CL
allowed region
C7SM
SM
18
BK*ll FB Asymmetry Good electroweak probe for bs loop.
q2 distribution has different pattern depending on sign(C7).
*10 9 7( ( ) ( ) )eff
FBA C sC s r s C
FBA
2( )GeV2q
b s
, Z
t
W b s
W W
t
q0(the point w/ AFB=0) is sensitive for New PhysicsSM; q0
2=(4.2±0.6)GeV2
B
K*
l
l
B
K*
l
l
Forward Backward
T. Rizzo
M=1.5TeV
M=1 TeV
AFB w/ KK gravition exchange
19
A9/A7
A1
0/A
7
AFB: Belle Summer ‘05
357fb-1 (386M BB) N(K*ll)=114+-14 (purity 44%) Unbinned M.L. fit to d2/dsd(cos)
– 8 event categories• Signal + 3 cross-feed + 4 bkg.
– Ali et al’s form factor– Fix |A7| to SM
– Float A9/A7 and A10/A7
Results;w/negative A7 (SM like)
w/positive A7
SMA9/A7
A10/A7
Sign of A9A10 is negative !
See Hep-ex/0508009 &A.Ishikawa’s talk at EPS05
20
Prospect at Super-B
@ 5ab-1
C9 ~ 11%C10 ~14%q0
2/q02 ~11%
1000 pseudo experiments w/ SM input values
Expected precision
5% at 50ab-1
21
Bl; leptonic decays
Proceed via W annihilation in the SM.
Branching fraction is given by
Provide information of fB|Vub|– |Vub| from BXu l fB cf) Lattice (~16%)
– Br(Bl)/md |Vub| / |Vtd|
Expected branching fraction3| | (3.67 0.47) 10ubV
(0.196 0.032)Bf GeV 5( ) (9.3 3.9) 10Br B
4 6 9~ 1 10 ( ) :~ 0.5 10 ( ) :~ 1 10 ( )Br e
22
Status of Leptonic Decay Search
Results @ Summer’05
23
Full Reconstruction Method
Fully reconstruct one of the B’s to tag– B production– B flavor/charge– B momentum
Υ(4S)
e (8GeV)
e+(3.5GeV)
B
B
full (0.1~0.3%)reconstructionBD etc.
Single B meson beam in offline !
Decays of interests BXu l , BK BD,
Powerful tools for B decays w/ neutrinos
24
Fully Reconstructed Sample
Belle (253fb-1): 275M BB 2.5x105 B0B0 + 4.2x105 B+B-
25
BStatus (Belle LP05/EPS05)
NBB (produced) = 275M NB+B- (full recon.)
= 4.0 x 105 (purity 0.55) Searched decay
modes
– Cover 81% of the decay
Event selection– Residual ECL energy
– Total net charge
etc.
, e 0, ,
0ii
Q
0.3residualE GeV
Obtained EresidualK.Ikado’s talk at EPS05hep-ex/0507034
4( ) 1.8 10 (90% )Br B CL
26
Prospect
Will soon reach the SM.– 3 at ~700 fb-1
– 5 at ~2 ab-1
Expected precisionat Super-B– 13% at 5 ab-1
– 7% at 50 ab-1
B will be the next major milestone ofthe Belle mission for rare decay search !B will be the next major milestone ofthe Belle mission for rare decay search !
27
Impact to Charged Higgs Br. with exchangeH
90%CL excluded regionat present
95% CL excluded regionat 5ab-1 (if Bobs = BSM)
rH
tan/mH
b
u H/W
28
Charged Higgs in BD Charged Higgs modifies semileptonic decay rates.
cb
W
(the heaviest lepton) is the most sensitive.
( )tan cotb c um m
tanm cb
H
+ exchangeH exchange (SM)W
Tanaka/ Miura
29
BD (MC studies)
Use fully reconstructed samples. T decay modes
Analysis cuts;– Reject events w/ p, KL– Reject D(*) contamination
– No remaining charged or 0 tracks– ECL residual energy
– Angle between two ’s
– Missing mass
0 02142 10MeV/D Dm m c
100residualE MeV
1.0 cos 0.8
2 2 21.2 ( / )B Dp p p GeV c
Signal
BG
, e , ,
30
Cont’d
5ab-1 50ab-1
Mode Nsig Nbkg dB/B Nsig Nbkg dB/B
280 55012.7 7.9%
2800 550040.3 2.5%
620 3600 6200 36000
0 ( )D
0 ( )D h
Expectation at 5 / 50 ab-1 for B+ decay
5 observation possible at 1ab-1
Signal selection efficiency0
0
( )
( )
e
e
D e
D
0
0
( )
( )
D
D
10.2%2.6%
26.1%13.3%
Major background sourceMissing charged and tracks from BD(*) l X (incl. slow )
31
Cont’d
(Fo
rm-fa
ctor
) ~15
%
(Fo
rm-fac
tor)
~5%Constraint
From bs
Present limit From B
32
Lepton Flavor ViolationQuarks have flavor mixing.
Neutrino mixing has been found.What about charged leptons ?
e
e
? ?
(Original figure by Dr. Kuno / Osaka Univ.)
B factory is also a tau factory
33
l SUSY + Seasaw Large LFV
l3ll
Br()=O(10-7~9)
2
32
4
262
( a101
) t nL
L
SUSY
BTeV
m
mr
m
3l,l • Neutral Higgs mediated decay.• Important when MSUSY >> EW scale.
462
7 322
tan 100
60
( 3 )
4 10A
L
L
B
G
m
r
m
m
eV
( ) : ( 3 ) : ( )
5 :1: 0.5
Br Br Br
( )e
0
( )e223(13)l
(m )
( )s
( )s
h
34
Analysis Method
Signal extraction– Calc. Minv and DE
• DE=Erec-Ebeam
– Blinded signal region Event selection study
– Estimate backgroundusing sideband data
– Open blind and estimate signal yield• Estimate upper limits
Signal MC of Signal
region
Background
35
/eat Belle
Background: /e + ISR (or beam background) Small amount of mm events in E>0
Br<3.1x10-7 at 90%C.L.
PRL 92, 171892 (2004).
Br<3.1x10-7 at 90%C.L.
PRL 92, 171892 (2004).
86.3fb-1 datae
Br<3.9x10-7 at 90%C.L.
PLB 613, 20 (2005).
Br<3.9x10-7 at 90%C.L.
PLB 613, 20 (2005).
36
l Belle: 87.1fb-1, PLB 598, 103 (2004)
Br<(1.1~3.5)x10-7 at 90%C.L.
Background: low level– qq for E<0, QED( or Bhabha) for DE>0
Signal region
37
B.R. Summary
Br < O(10-6) in PDG (by CLEO) Br < O(10-7) by Belle and BaBar
38
Super B-factory : >10 times more data
– B.R. sensitivity: ~1/n for negligible BG case ~1/n for BG dominating modes
Future prospect
39
Future prospect (2)
Possible sensitivity with Super B-factory – Red band for 5~10ab-1
SuperB-factory
40
l SUSY + Seasaw Large LFV
Constraint to NP
Br()=O(10-7~9)
0tanβ=30,A =0,μ>0Gaugino mass = 200GeV
Super-BPresent Belle
2
32
4
262
( a101
) t nL
L
SUSY
BTeV
m
mr
m
3l,l • Neutral Higgs mediated decay.• Important when MSUSY >> EW scale.
462
7 322
tan 100
60
( 3 )
4 10A
L
L
B
G
m
r
m
m
eV
41
Interplay between B and
J.Hisano @ Tau04Workshop, Nara,Nov, 2004.
J.Hisano, Y.ShimizuPLB565(2003)183.
42
Concluding Remarks
No New Physics Indication Yet ! Need more luminosity.
This year:Crab cavity installation
Future: Super-KEKB
Stay tuned !
43
Future
Let’s discuss together– Role of flavor physics– Synergy with LHC YES NO
YES 1 3
NO 2 4LHC
Flavor Phys(ex. Super-B)
NP evidence
1. We will be busy! Scenario of studies ?2. Scenario of studies ? 3. How significant is the null result at F.P. to constrain NP model.4. Where do we go ?
1. We will be busy! Scenario of studies ?2. Scenario of studies ? 3. How significant is the null result at F.P. to constrain NP model.4. Where do we go ?
44
CERN Flavor WS
Nov. 7-10, 2005 Feb. 6-8, 2006 May.15-17, 2006 Final report at
2006/end or 2007/beg.
Discuss synergy between Flavor Physics (B/C/K/t/m etc.) and LHC.
Bench mark model & parameters for studies.
Let’s discuss together !
45
Backup
46
Radiative Decays
Inclusive Br(bs) |C7|, SF for |Vub| BK* isospin asymmetry (+-)sign of C7
Mixing induced CPV Direct CPV in BXs BXd
Summary by M.Nakao1st Super-B workshopat Hawaii
47
B0KS0 tCPV: Belle Summer ‘05
386MBB M(Ks0) < 1.8GeV/c2
– NP effect is independent of the resonance structure. Two M(Ks0) regions(MR1:0.8-1.0GeV/c2 / MR2: <1.8GeV/c2) 70+-11 (45+-11) events in MR1(2).
Atwood, Gershon, Hazumi, Soni, PRD71, 076003 (2005)
ResultS= +0.08 ±0.41 ±0.10 A= +0.12±0.27±0.10
Good tag (0.5<r<1.0)
0.0050.0110.051 / 0.038Acpdir(BXs)
0.040.140.41 / 0.10Acpmix(BK*K*Ks0)
50ab-15ab-1Present Belle (stat./syst.)
48
Acp(BXs) vs SUSY models
mSUGURAtan=30
U(2)tan=30
SU(5)+R
tan=30degenerate
SU(5)+R
tan=30non-degenerate
( )gm GeV
mSUGURAtan=30
U(2)tan=30
SU(5)+R
tan=30degenerate
SU(5)+R
tan=30non-degenerate
( )gm GeV
Mixing CPVDirect CPV
Acp
dir
Acp
mix
5ab-1 50ab-1
T. Goto, Y.Okada, Y.Shimizu,T.Shindou, M.Tanakahep-ph/0306093, also in SuperKEKB LoI
49
Constraint to Charged Higgs
Once branching fraction is measured, we can constrain R.
tanW
H
MR
M
Form factor error
M.Tanaka, Z.Phys. C67 (1995) 321
11R at 5ab-1 can be determined experimentallyby B semiletonic decays