View
222
Download
0
Embed Size (px)
Citation preview
Belle/KEB status & plans
φ1, φ2, φ3; penguins; new particles;…
+plans for Super-KEKB/Belle
S.L. OlsenU. of Hawai’i
P5 meetingSLAC 10/5/05
KEKB Collider
The KEKB Collider (8 x 3.5 GeV, X angle)
L=(1.6 x 1034)/cm2/sec Int(L dt)= 469 fb-1 On- resonance~420fb-1
Status of Asymmetric B FactoriesStatus of Asymmetric B Factories
KEKB
PEP-II
Used this summer
Ldt 2(t/14mo)
Normal injection Continuous injection
1182 pb/day661/pb/day
collaboration
Detector performance
0.3%
Pt resolution ( in %) M(0) resolution ( in MeV)
4.5MeV
100MeV1 GeV/c 1 GeV
(B: 8MeV) (B: 21MeV)
Particle ID in Belle
~8%
~80%
SVD Occupancy
Present : layer 1 of SVD
~10% occupancy / 200 Krad.yr-1
L~1.6x1034 → L~5x1034 cm-2s-1 ???
~10% ~4%
~2% ~2%SVD2
w/o Event Builder
Upgrade
DAQ upgrades
Present operation
Faster signal processingwith CMS chip in SVD(Silcon vertex det.)
New pipelined dataAcquisition system (COPPER)
The B Factory Physics Program
1) Measure of Fundamental SM Params:
CKM elements & phases
2) Search for New Physics:
look for evidence of new particles in loops
3) Unanticipated new phenomena:
large (e+e-cccc), X(3872),Y(3940),..
4) + lots of “bread & butter”
c’, c2’, D**,c*, -physics, spin frag-fcn,…
Warning: I can only give a few small tastes from this rich & flavorful menu
B0
B0B0
Vcb
VtbV*
V*Vtb
J/
J/
KS
KS
sin21 from BfCP + BBfCP interf.
V*2
td
td
td
Sanda, Bigi & Carter:
Principle of CPV Measurement
t z/(cβγ)
(B0 or B0 ?)
B - B
B + B
= (1-2w)sin21= (1-2w)sin21
more B’s
more B’s
fCP
t=0z
J/ (
KS
2005: B2005: B00 J/ J/ K K00 w/386 M BB pairs w/386 M BB pairs
2*/
2*KsJbeambc PEM
B0 J/ KS B0 J/ KL
Nsig = 5264Purity 98 %
CP odd Nsig = 4792Purity 60 %
CP even
0 0
__
CP side:t0.5ps tag side:t0.9ps
2005: B2005: B00 J/ J/ K K00
BG subtracted distributions(good tag region)
sin21= 0.652 ±0.039 (stat) ±0.020 (syst) A = 0.010 ±0.026 (stat) ±0.036 (syst)
previous resultsin2= 0.728 0.061
(152 M BB pairs)consistent ~1.2
B0 tag_B0 tag
_
_
11 measurement measurement
1~20o
1~70o
sin21
1
2-fold ambiguity21 -21
?
?
BB00 D D00hh00
Belle’s New Method for Direct measurement of Belle’s New Method for Direct measurement of 11
__(D0 KS
M(KS)
M(KS)
f-+
M(KS)
M(KS)f+-
AB0D0h0(t) =
cos(Mt/2)
sin(Mt/2) -ei21 h0
Reconstruction of BReconstruction of B00 D[K D[KSS++--]h]h00
D0 0 D0 D0 D*0 0,
Nsig = 157 ±24purity : 59%
Nsig = 67 ±10purity : 86%
Nsig = 58 ±13purity : 60%
Nsig = 27 ±11purity : 52% D*0 D0 0
TOTALNsig = 309 ±31
purity : 63%
__
Time-Dependent Dalitz fit resultsTime-Dependent Dalitz fit results
Final state 1 (o)
D0 0 11 ± 26
D0 28 ± 32
D*0 0, 25 ± 35
combined 16 ±21(stat) ±11(syst)
-30o < 1 < 62o
(95% C.L.)
Belle preliminary
Implications of Time-dependent Dalitz analysisImplications of Time-dependent Dalitz analysis
1~20o
1~70o
sin21
1
?
?
(^_^)
2-fold ambiguityresolved !
Consistent with B0J/K* results cos21 = 0.87 ±0.75, hep-ex/0504046
Disfavored>2
07.015.058.0 A07.021.000.1 S
5.2CPV,
First evidence for DCPV (3.2σ)
Belle 152 M BB
with 372±32 B0→+− events
04.015.009.0 A03.017.030.0 S
BABAR 227M BB
hep-ex/0501071
Also ~3.2 difference between Belle and BaBar
PRL 93, 021601 (2004)
with 467±33 B0→+− events
Experimental Situation for B+ - in 2004
E-Mbc 2D fits to individual time intervals
B0 tagged B0 tagged
t (ps)
+−
AC
P
+−
Yie
ld2005 results: Bkg subtracted B+ - projections
06.016.067.0
06.012.056.0
S
A
4signal for Direct CPV
& 18071 2
190 2
2005: Status of B+ -
Belle 275M
BABAR 227M
A
~2.3 difference between Belle and BABAR
S
S
- A(C)
275M BBbar pairs
62.04.03.05.0
00 10)3.2()( Br
17.044.0)( 53.052.0
00 CPA
hep-ex/0408101published in PRL
Belle’s measurement of ACP(B0 0 )
CPV in B0 +
B VV: not a single CP eigenstate + +0: wide resonance, two 0’s in the final state.
B(00) << B(+), B(+0) < 1.1 30 6 (26 6 ) x 10-6 (HFAG Winter05)
small Penguin pollution () 2A00
A+0
A+-/ 2
fL ~ 100% CP +1
Similar to B+, but in principle more complicated …
Three miracles:
B()NR and int. small
B = 24.4 2.2
x 10-6
275M BB275M BB
B0 + signalB0 + signal
3.84.1
fL= 0.951 0.0290.031
0.0330.039 [Belle-CONF-0545]
continuum
b c
b u
Helicity M
signal
signal
continuum
continuum
2005: Belle Results on CPV in B2005: Belle Results on CPV in B++--
)(08.0)(42.009.0
)()(30.000.0 10.009.0
syststatS
syststatA
Results:
Low quality tag
High quality tag
q=1 q=-1
Preliminary (274 106 BB pairs)
No CPV φ2 is near 900
Belle Constraints on Belle Constraints on 2 2 ((αα))
11559
1787
2
2
at 90% CL
B [hep-ex/0502035] & combined
11375
93
2
12112
at 90% CL
B only
3 () measurement
1
2
3
Vtd Vtb
Vcd Vcb
Vud Vub*
*
*
u
b
u
uc
sW
B+d
D0
Vcs
Vub
u
b
u
su
c
W
B+d D0
+Vus
Vcb _fCOMfCOM
Interference of bc and bu diagrams
Simple mixing CPV 3 (with Bd )+
Tree
3) 3)
Tree
Belle method for 3: Dalitz 3) fCOM = D KS
B+:
B-:
m+=m(Ks+), m=m(Ks) CPV: Asymmetry in Dalitz dist.:
r
r |A2|
|A1|r =
2m
2m
0 D 2m
2m
0 D obtainfromtagged D0
(D*+ D0+)sample
BD(*) K(*), DKS +-275M BB275M BB
D0K D*0K[D00]
D0K*36signal
209signal
58signal
[hep-ex/0411049]
[hep-ex/0504013]
3 Results (Belle and BaBar)
[hep-ex/0504039]
[hep-ex/0411049,0504013]
3 = 63 deg.3 = 63 deg.1513
(Non-trivial constraint)
Current status
consistent with constraints from measmts of lengths of sides only:
η=0.342±0.022
=0.216±0.036
CPV angles only:η=0.321±0.027=0.193±0.57
Simplistic(?) summation: 1+ 2+ 3 182o ~20o
SM with KM ansatz works remarkably well for tree-level
processes
Next step: use bs penguinsExample:
no KM phase
SM: sin21 = sin21 from BJ/ KS (bc c s)
unless there are other, non-SM particles in the loop
eff
Vtd
Vtd
+
1
B B
, ’,
1
, ’,
_
*
*
How New Physics contributes to bs
0B
b ss
sd
d
W
g
, ,u c t
“Internal Penguin”
0SK
0B
0SK
0 0 B K
0 0 B K
0SK
0B
b
s
s
sd d
0SK
0B
b
s
s
sd d
Many new phases are possible in SUSY
New physics in loops?
Belle 2005:
Significant CP Violation in a bs penguin mode!!
>>all systematically below sin(2)
>>QCD corrections : sin2(penguin)>sin2(tree)
[Beneke, hep-ph/0505075][Cheng,Chua,Soni, hep-ph/0506268]
recent QCD factorization estimates :
sin2φ1(penguin)-sin2φ1(tree)
Many bs modes were studied:
sin21(penguin) = 0.50 0.06
(HFAG’s “naïve average”)
0.4-
B Kl +l - K*l +l -
(loops with virtual
t’s, W’s, & Z’s)
EW penguins
1st measurement of AFB(BK* l l)
Interference btw and Z
AFB (Kl +l -) = 0.09 0.14 (stat)AFB(K*l +l - ) = 0.56 0.13 (stat)
already rules out some new physics scenarios
First Observation of bd
Addresses the same physics issue as Bs- Bs mixing (future Tevatron RunII goal).
_
signal
K*other B
2BR( / )
BR( )td
ts
B
B
V
VK
Same physics as Bs mixing
68%CL
95%CL
Full UT fit
Implications of Belle’s observation of bd
bonuses: new mesons, many puzzles!
c’X(3872)
Z(3931)c2’?
e+e-cccc Y(4260)
Y(3940)
M(J/) MeV
c”??
not seen in (e+e-hadrons)at Ecm =4.26 GeV
Y(4260)
???
KEKB near term
• During the recent summer shutdown (2005)– one more RF station for ARES cavity (a klystron, low level
control …) in HER (to be named as D5E)• Increase of the HER beam current by about 150mA• One RF station costs about 2 Oku-yen.
– new movable masks in LER: Cu head – solenoids for electron cloud
• Upgrade the 50 power supplies for solenoid coils (3A -> 5A)• test of thin coils inside quadrupole magnets
– 3.5 3.27 (lower?) bucket spacing?• Crab cavity (Jan 2006)
– A crab cavity for the purpose of raising the beam-beam parameters is scheduled to be installed in each ring at the beginning of 2006.
Comparison of Specific Luminosity3.5 bucket spacing
3.77 bucket spacing
Crab crossing in Jan 2006
crossing angle 22 mrad
Head-on (crab)
◊
◊◊
◊◊
ξy
(Strong-weak simulation)
(Strong-strong simulation)
Crab crossing may boost the beam-beam parameter up to 0.19 !
Superconducting crab cavities are under development, will be installed in KEKB in early 2006.
K. Ohmi
K. Hosoyama, et al
Lumiinosity projections for KEKB
~1010 BB/year !!& similar number
of +-
Lpeak = 1.61034 cm-2s-1
Ltot = 469fb-1
1.6x1034
469 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 !
Interaction RegionCrab crossing
=30mrad.y*=3mm
New QCS
SuperKEKB: 2010
Linac upgrade
More RF power
Damping ring
New Beam pipe
Ante-chamber & solenoid coilsto reduce photo-electron clouds
Bkg & TRG rate in futureBkg & TRG rate in future
KEKB SuperB
Luminosity(1034cm-2sec-1)
~1 50
HER curr. (A)
LER curr. (A)vacuum (10-7Pa)
1.2
1.6
~1.5
4.1
9.4
5
Bkg increase - x 20
TRG rate (kHz)phys. origin
Bkg origin
0.40.2
0.2
1410
4Shynchrotoron radiationBeam-gas scattering (inc. intra-beam scattering)Radiative Bhabha
SVD CDC PID / ECL KLM
KEKBBkg
x10 Bkg
x20 Bkg
Belle tracking with 20x background
now Bkg x 20
- low p identification s recon. eff.- hermeticity “reconstruction”
- radiation damage and occupancy- fake hits and pile-up noise in the EM
- higher rate trigger, DAQ and computingIssues:
Higher background ( 20)
Higher event rate ( 10)
Require special features
Belle Upgrade for Super-B
SC solenoid1.5T
New readout and computing systems
CsI(Tl) 16X0
pure CsI (endcap) Aerogel Cherenkov counter + TOF counter
“TOP” or DIRC
Si vtx. det. 4 lyr. DSSD 2 pixel/striplet lyrs. + 4 lyr. DSSD
Tracking + dE/dx small cell + He/C2H5
remove inner lyrs.
fast gas+Si r<20 cm
/ KL detection 14/15 lyr. RPC+Fe
tile scintillator
CKM Unitarity Triangle at 50 ab1
1(penguins) (indiv. Modes)
1(trees)
AFB(BK l+ l-)[q2] at Super Belle
• Assume 1 year of running at 5x1035/nb/sec 5/ab integrated luminosity, 10 billion B
mesons!!– At present, ~0.46/ab
A9/A9~11%, A10/A10~13%– A7 fixed to SM value
Belle Toy MC with 5/abC10
NP
C9NP
Donut : B(BXsll) with140/fb + 100/fb
AFB K*ll with 5/ab
Determine location of the zero crossing
Possible schedule for Super B
2004 05 06 07 08 09 10 11 12
KEKB SuperKEKB>1000fb-1
Calendar year
Crab cavity
KEKBmachine
SuperKEKB const.
J-PARC 1 construction ILC constructionConstruct.fund
“Minor” upgrade “Major” upgradeBelle
Operationfund
T2K
budget for Super B
J-PARC constructionends here
A “balanced” world program for HEP
Newphysics
Quark sectorLepton sectorEn
ergy
fron
tier
experiments,g-2, e, etc.
Super B factory, LHCb, K experiments etc.
LHC, ILC
mass and mixing,CPV, and LFV
Mass spectrum,interactions
Flavor mixing,CP phases
LFV, CPV
Final comment
The most important single contributing element to whatever success Belle & KEKB has had to date has been the stimulating & enervating competition with BaBar and PEP-II.
Belle & KEKB people sincerely hope this very productive competition will continue.
Backup Slides
.“Observation” of Direct CP violation in BK- +
One more nail in the Superweak coffin.
Evidence for BK0 K (hadronic bd s s processes)
Belle@250 fb-1
_
Measurements of B K0 K0 CPV at Super B will be possible.
Super KEKB parameters