Transcript Slide 1
Belle/KEB status & plans
P5 meeting
SLAC 10/5/05
S.L. Olsen
U. of Hawai’i
φ1, φ2, φ3; penguins; new particles;…
+plans for Super-KEKB/Belle
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
KEKB Collider
Status of Asymmetric B Factories
Used this summer
KEKB
Ldt 2(t/14mo)
PEP-II
Normal injection
Continuous injection
661/pb/day
1182 pb/day
collaboration
Detector performance
Pt resolution (s in %)
M(p0) resolution (s in MeV)
(Bp+p-: s(DE)21MeV)
(Bp0p0: sM(p0)8MeV)
4.5MeV
0.3%
1 GeV/c
100MeV
1 GeV
Particle ID in Belle
~80%
~8%
SVD Occupancy
Present : layer 1 of SVD
~10%
~4%
~2%
~2%
~10% occupancy / 200 Krad.yr-1
SVD2
L~1.6x1034 → L~5x1034 cm-2s-1 ???
DAQ upgrades
w/o
Event Builder
Upgrade
Present
operation
Faster signal processing
with CMS chip in SVD
(Silcon vertex det.)
New pipelined data
Acquisition 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 s(e+e-cccc), X(3872),Y(3940),..
4) + lots of “bread & butter”
hc’, cc2’, D**,Sc*, t -physics, spin frag-fcn,…
Warning: I can only give a few small tastes from this rich & flavorful menu
sin21 from BfCP + BBfCP interf.
Sanda, Bigi & Carter:
Vcb
J/y
B0
KS
+
V*td
J/y
Vtb
B0
B0
Vtb
V*
td
KS
2
V*
td
Principle of CPV Measurement
(B0 or B0 ?)
J/y (r+)
fCP
t=0
B-B
B+B
KS (r-)
Dz
more B’s
more B’s
t Dz/(cβγ)
= (1-2w)sin21
= (1-2w)sin21
_
2005: B0 J/y K0 w/386 M BB pairs
B0 J/y KS0
Nsig = 5264
Purity 98 %
CP odd
*2
M bc Ebeam
- PJ*/2yKs
B0 J/y KL0
Nsig = 4792
Purity 60 %
CP even
CP side:s(Dt)0.5ps tag side:s(Dt)0.9ps
_
2005: B0 J/y K0
sin21= 0.652 ±0.039 (stat) ±0.020 (syst)
A = 0.010 ±0.026 (stat) ±0.036 (syst)
B0 tag
_
B0 tag
BG subtracted distributions
(good tag region)
previous result
sin21= 0.728
_ 0.061
(152 M BB pairs)
consistent ~1.2s
1 measurement
1~70o ?
sin21
?
1~20o
1
2-fold ambiguity
21 p-21
_
(D0 KSp+p-)
Belle’s New Method for Direct measurement of 1
B0 D0h0
AB0D0h0(Dt) =
M(KSp-)
f-+
cos(DMDt/2)
M(KSp+)
-)
i2
M(K
p
1
S
-e hh0
f+M(KSp+)
sin(DMDt/2)
_
Reconstruction of B0 D[KSp+p-]h0
D0 p 0
Nsig = 157 ±24
purity : 59%
D0 w
Nsig = 67 ±10
purity : 86%
D0 h
D*0 p0, h
Nsig = 58 ±13
purity : 60%
Nsig = 27 ±11
purity : 52%
D*0 D0 p0
TOTAL
Nsig = 309 ±31
purity : 63%
Time-Dependent Dalitz fit results
Belle preliminary
Final state
1 (o)
D0 p0
11 ± 26
D0 w, h
28 ± 32
D*0 p0, h
25 ± 35
combined
16 ±21(stat) ±11(syst)
-30o < 1 < 62o
(95% C.L.)
Implications of Time-dependent Dalitz analysis
Consistent with B0J/yK* results
cos21 = 0.87 ±0.75, hep-ex/0504046
1~70o ?
sin21
(^_^)
?
1~20o
1
2-fold ambiguity
resolved !
Disfavored
>2s
Experimental Situation for Bp+ p- in 2004
Belle 152 M BB
with 372±32 B0→p+p− events
Spp -1.00 0.21 0.07
App +0.58 0.15 0.07
PRL 93, 021601 (2004)
BABAR 227M BB
with 467±33 B0→p+p− events
Spp -0.30 0.17 0.03
App +0.09 0.15 0.04
hep-ex/0501071
5.2s CPV,
First evidence for DCPV (3.2σ)
Also ~3.2s difference between Belle and BaBar
B0 tagged
B0 tagged
4s signal for Direct CPV
App +0.56 0.12 0.06
Spp -0.67 0.16 0.06
p+p− A
CP
p+p− Yield
2005 results: Bkg subtracted Bp+ p- projections
DE-Mbc 2D fits to individual
time intervals
0 2 19
&
Dt (ps)
71 2 180
App
2005: Status of Bp+ p-
Belle
275M
Spp
BABAR 227M
~2.3s difference between
- App
Belle and BABAR
(Cpp )
Spp
Belle’s measurement of ACP(Bp0 p0 )
Br(p 0p 0 ) (2.3+-00..45+-00..23 ) 10-6
ACP (p 0p 0 ) +0.44+-00..53
52 0.17
275M
BBbar
pairs
hep-ex/0408101
published in PRL
CPV in B0 r+rSimilar to Bp+p-, but in principle more complicated …
B VV: not a single CP eigenstate
r+ p+p0: wide resonance, two p0’s in the final state.
Three miracles:
fL ~ 100% CP +1
Br(pp)NR and int. small
B(r0r0) << B(r+r-), B(r+r0)
(26 6 ) x 10-6 (HFAG Winter05)
A+-/ 2
2q
small Penguin pollution (q )
A00
< 1.1
30 6
A+0
B0 r+r- signal
275M BB
continuum
bc
signal
bu
B = 24.4 2.2
3.8
4.1
x 10-6
Mpp
Helicity
continuum
continuum
signal
r pp
0.029
fL= 0.951 0.033
0.039
0.031
[Belle-CONF-0545]
2005: Belle Results on CPV in Br+rPreliminary (274 106 BB pairs)
q=1
q=-1
Low quality
tag
High quality
tag
Results:
Arr 0.00 0.30( stat ) +-00..10
09 ( syst )
S rr 0.09 0.42( stat ) 0.08( syst )
No CPV φ2 is near 900
Belle Constraints on 2 (α)
Bpp [hep-ex/0502035] & rr combined
Brr only
2 87 17
59 2 115
2 93
at 90% CL
+12
-11
75 2 113 at 90% CL
3 () measurement
Vud Vub* (a)
2
Vtd Vtb*
3()
Simple mixing CPV
3 (with Bd )
1(b)
*
Vcd Vcb
Tree
b
+
d
B
u
Vub
W
Vcs
O(l3)
Vus
u
c
s
u
D0
fCOM
K+
b
B
+
d
u
Tree
W
Vcb
O(l3)
Interference of bc and bu diagrams
s
u
K+
c
_
D0
u
fCOM
Belle method for 3: Dalitz
3) fCOM = D0 KSp+pB+:
m-2
r
D0
m
D0
2
-
m+2
B-:
obtain
from
tagged D0
(D*+ D0p+)
sample
m+2
r
r
|A2|
= |A |
1
CPV: Asymmetry in Dalitz dist.: m+=m(Ksp+), m-=m(Ksp-)
BD(*) K(*), DKS p+p-
275M BB
209
signal
D0K
58
signal
D*0K
[D0p0]
36
D0K*
signal
[hep-ex/0411049]
[hep-ex/0504013]
3 Results (Belle and BaBar)
[hep-ex/0411049,0504013]
3 = 63
[hep-ex/0504039]
15
13
deg.
(Non-trivial constraint)
Current status
CPV angles only:
η=0.321±0.027
r=0.193±0.57
consistent with
constraints from
measmts of lengths
of sides only:
η=0.342±0.022
r=0.216±0.036
Simplistic(?)
summation: 1+ 2+ 3 182o ~20o
SM with KM ansatz works
remarkably well for tree-level
processes
Next step: use bs penguins
Example:
no KM phase
*
Vtd
, h’, K+K-
+
Vtd*
SM:
, h’, K+K-
B
B
eff
sin21 = sin21 from
1
1
_
BJ/y KS (bc c s)
unless there are other, non-SM particles in the loop
How New Physics contributes to bs
B 0 K 0
b
d
W+
New physics in loops?
u , c ,t
g
B0
s
s
s K0
d S
b
d
s
KS0
d
Many new phases are
possible in SUSY
B 0 h K 0
h
B0
s
B0
“Internal Penguin”
s
h
KS0
b
s
s
B0
d
h
s
KS0
d
Belle 2005:
Significant CP Violation in a bs penguin mode!!
>>all systematically below sin(2b)
Many bs modes were studied:
>>QCD corrections :
sin2b(penguin)>sin2b(tree)
recent QCD factorization estimates :
[Beneke, hep-ph/0505075]
[Cheng,Chua,Soni, hep-ph/0506268]
sin2φ1(penguin)-sin2φ1(tree)
sin21(penguin) = 0.50 0.06
(HFAG’s “naïve average”)
0.4-
EW
penguins
(loops with virtual
t’s, W’s, & Z’s)
B Kl +l - K*l +l -
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
signal
qq
K*
other B
_
Addresses the same physics issue as Bs- Bs mixing
(future Tevatron RunII goal).
Implications of Belle’s observation of bd
BR(B ( r / w ) )
BR(B K )
Vtd
Vts
2
Same physics as Bs mixing
68%CL
95%CL
Full UT fit
r
bonuses:
new mesons, many puzzles!
hc’
Z(3931)
cc2’?
X(3872)
Y(3940)
e+e-cccc
not seen in s(e+e-hadrons)
at Ecm =4.26 GeV
Y(4260)
Y(4260)
hc”??
M(wJ/y) MeV
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 Luminosity
3.5 bucket spacing
3.77 bucket spacing
Crab crossing in Jan 2006
Crab crossing may boost the beam-beam parameter up to 0.19 !
y
(Strong-weak simulation)
K. Ohmi
Head-on (crab)
◊
◊
◊
◊
◊
(Strong-strong simulation)
crossing angle 22 mrad
Superconducting crab cavities are
under development, will be installed in
KEKB in early 2006.
K. Hosoyama, et al
Lumiinosity projections for KEKB
Lpeak = 1.61034 cm-2s-1
Ltot = 469fb-1
world records !
~1010 BB/year !!
& similar number
of t+t-
Major upgrade of
KEKB & Belle detector
(>1yr shutdown)
crab
cavities
Lpeak (cm-2s-1) 1.6x1034
Lint
469 fb-1
5x1034
~1 ab-1
5x1035
~10 ab-1
SuperKEKB: 2010
Interaction Region
Crab crossing
q=30mrad.
by*=3mm
New QCS
New Beam pipe
More RF power
Ante-chamber & solenoid coils
to reduce photo-electron clouds
Damping ring
Linac upgrade
Bkg & TRG rate in future
x20 Bkg
KEKB SuperB
Luminosity
~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)
0.4
14
phys. origin
Bkg origin
0.2
0.2
10
4
(1034cm-2sec-1)
x10 Bkg
KEKB
Bkg
SVD
CDC PID / ECL KLM
Shynchrotoron radiation
Beam-gas scattering (inc. intra-beam scattering)
Radiative Bhabha
Belle tracking with 20x background
Bkg x 20
now
4 Higher background ( 20)
Issues:
- radiation damage and occupancy
- fake hits and pile-up noise in the EM
4 Higher event rate ( 10)
- higher rate trigger, DAQ and computing
4 Require special features
- low p m identification f smm recon. eff.
- hermeticity f n “reconstruction”
Belle Upgrade for Super-B
SC solenoid
1.5T
m / KL detection
14/15 lyr. RPC+Fe
CsI(Tl) 16X0
g pure CsI (endcap)
Aerogel Cherenkov counter
+ TOF counter
“TOP” or DIRC
g tile scintillator
Tracking + dE/dx
small cell + He/C2H5
gremove inner lyrs.
fast gas+Si r<20 cm
New readout
and
computing
systems
Si vtx. det.
4 lyr. DSSD
g 2 pixel/striplet lyrs.
+ 4 lyr. DSSD
CKM Unitarity Triangle at
1(trees)
1(penguins)
(indiv. Modes)
50 ab-1
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
DA9/A9~11%, DA10/A10~13%
– A7 fixed to SM value
AFB K*ll with 5/ab
Donut : B(BXsll)
with140/fb + 100/fb
Belle Toy MC with 5/ab
Determine location of the zero crossing
C10NP
C9NP
Possible schedule for Super B
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
budget for Super B
J-PARC construction
ends here
A “balanced” world program for HEP
n experiments,
gm-2, mge, etc.
LHC, ILC
n mass and mixing,
CPV, and LFV
Mass spectrum,
interactions
New
physics
Quark sector
t LFV,
t CPV
Flavor mixing,
CP phases
Super B factory,
LHCb, K experiments etc.
Final comment
The most important single contributing
element to whatever success Belle & KEKB
has had to date has been the stimulating
& energizing competition with BaBar and
PEP-II.
Belle & KEKB people sincerely hope this
very productive competition will continue.
Backup Slides
.“Observation”
One more nail in the
Superweak coffin.
of Direct CP violation in BK- p+
0 K
Evidence for BK
_
(hadronic bd s s processes)
Belle@250 fb-1
Measurements of B K0 K0 CPV
at Super B will be possible.
Super KEKB parameters