Observation of Anomalous e+e-  (nS)h+hProduction at (5S) Energies
November 8, 2007, HEP Seminar @ NTHU
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 1
Outline
• Motivation
• (4S), (3S)  (1S)p+p- Template
• Dataset on (5S)
• Event Selection for (nS)h+h• Results
• Discussion
• Summary
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 3
Motivation
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 4
Motivation I: because it’s there
Belle has ~ 20 fb-1 (5S) data
G ≃ 110 MeV
Gee ≃ 0.13 keV
G ≃ 20.5 MeV
Gee ≃ 0.27 keV
477 fb-1
20.5
110
~ 1.7 x 10-5
expect limits only ...
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 5
Motivation II: Enhancement?
PRD 74, 017504 (2006)
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 6
Motivation II: Enhancement?
Conceived during FPCP2006
April ’06 in Vancouver
New (5S) decays from Belle
George W.S. Hou (NTU)
PRD 74, 017504 (2006)
NTHU HEP, 11/08/2007 7
Motivation of Motivation
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 8
Motivation of Motivation
1- -
Shuwei YE
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 9
Y(4260)
Motivation II: Enhancement?
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 10
Note to myself
~ 7/13/05
Shuwei YE
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 11
Shuwei YE
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 12
Shuwei YE
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 13
Guestimates
─
Mass: Use QQg hybrid (CLEO favored) lattice work to illustrate
- 10600 - 10900 MeV (Michael)
─
Could scale down, ∵ ccg
prediction typically higher than Y(4260)
➯ Could show up in ISR on (5S) 10865
- 10900 – 11000 MeV (Juge, Kuti, Morningstar)
─
Predicted ccg
state ~ 4260
➯ Prefers Higher Energy Scan
Width: 100 MeV (~ Yc = Y(4260)) plausible
Product BR:
Assume
~
BaBar/CLEO
Could be smaller or larger
Xb/Yb
New (5S) decays from Belle
George W.S. Hou (NTU)
George W.S. Hou (NTU)
ICHEP’06, 7/28/06 11
NTHU HEP, 11/08/2007 15
Motivation II: Enhancement?
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 16
Backdrop: Data on (5S)
• 1985: CUSB, CLEO @ CESR ~ 116 pb-1
• 2003: CLEO III @ CESR
~ 0.42 fb-1
• June 2005: Belle @ KEKB ~ 1.86 fb-1
engineering run
• June 9-31, 2006: Belle @ KEKB
≅ 21.7 fb-1
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 17
Hint of events above background
1.86 fb-1
(2S)
(3S) (4S)
(5S)
Rough study
~ 9/2006
(post summer)
Took a year to analyze 21.7 fb-1, solely because of “computing”.
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 18
(3S), (4S)  (1S)p+p- Template
Old subject
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 19
(3S)  (1S)p+p- Understanding
(for (3S)  p+p- + nothing)
PRL 98, 132001 (2007)
2.9 fb-1
PRD 75, 072001 (2007)
1.14 fb-1
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 20
Data from (3S) Run
528 ± 24
3S
2S
(3S)(2S)p+p-
(3S)(1S)p+p-
1315 ± 39
1S
(2S)(1S)p+p4556 ± 70
More can be done at Belle ...
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 21
Data from (3S) Run
(2S)(1S)p+p-
(3S)(1S)p+pMoxhay Model
Brown-Cahn Model
CLEO Model
CLEO Model
(3S)(2S)p+pCLEO Model
Brown-Cahn Model
Much better
data than CLEO
PRD 75, 072001 (2007)
☞ allow Ep1Ep2 term !
CLEO Model
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 22
(4S)  (1S)p+p- Template
PRD 75, 071103(R) (2007)
~ 10-4
477 fb-1
2S
3S
4S
211 fb-1
PRL 96, 232001 (2006)
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 23
Data on (4S)
(2S)(1S)p+p-
(3S)(1S)p+p-
CLEO Model
CLEO Model
(4S)(1S)p+p-
Brown-Cahn Model
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 24
(3S), (4S)  (1S)p+p- Template
Published papers by
Belle, BaBar and CLEO
So, (5S) straightforward.
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 25
Dataset on (5S)
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 26
International Collaboration: Belle
BINP
Chiba U.
U. of Cincinnati
Ewha Womans U.
Fu-Jen Catholic U.
U. of Giessen
Gyeongsang Nat’l U.
Hanyang U.
U. of Hawaii
Hiroshima Tech.
IHEP, Beijing
IHEP, Moscow
IHEP, Vienna
ITEP
Kanagawa U.
KEK
Korea U.
Krakow Inst. of Nucl. Phys.
Kyoto U.
Kyungpook Nat’l U.
EPF Lausanne
Jozef Stefan Inst. / U. of
Ljubljana / U. of Maribor
U. of Melbourne
Nagoya U.
Nara Women’s U.
National Central U.
National Taiwan U.
National United U.
Nihon Dental College
Niigata U.
Nova Gorica
Osaka U.
Osaka City U.
Panjab U.
Peking U.
Princeton U.
Riken
Saga U.
USTC
Seoul National U.
Shinshu U.
Sungkyunkwan U.
U. of Sydney
Tata Institute
Toho U.
Tohoku U.
Tohuku Gakuin U.
U. of Tokyo
Tokyo Inst. of Tech.
Tokyo Metropolitan U.
Tokyo U. of Agri. and Tech.
INFN Torino
Toyama Nat’l College
VPI
Yonsei U.
14 countries, 55 institutes, ~400 collaborators
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 27
The KEKB Collider
SCC RF(HER)
Belle detector
World record:
L = 1.7118 x 1034/cm2/sec
First successful op. of Crab cavities
ARES(LER)
8 x 3.5 GeV
22 mrad crossing
Ares RF
cavity
Mt. Tsukuba
KEKB
Belle
e+ source
since 1999
New (5S) decays from Belle
~ 1 km in diameter
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 28
Belle Detector
ACC (PID)
Aerogel Cherenkov Counter
SC Solenoid
n=1.015~1.030
1.5T
3.5 GeV e+
ECL CsI(Tl)
16X0
TOF
8 GeV e-
CDC
Central Drift Chamber
small cell +He/C2H6
KLM
SVD Si Vertex Detector
3(4) lyr. DSSD
New (5S) decays from Belle
George W.S. Hou (NTU)
m / KL detection
14/15 lyr. RPC+Fe
NTHU HEP, 11/08/2007 29
Dataset on (5S)
Main Purpose
e.g.
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 30
Event Selection for (nS)h+h-
h = p, K
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 31
Event Selection for (nS)h+h Track
Prompt: within 5 cm of IP in z (beam direction)
1 cm
in transverse
 m+m- + h+h - (+ X0
Muon ID;
loose h = p, K
No other charged tracks with pT > 100 MeV/c2
 |M(m+m-) - M((nS))| < 150 MeV/c2 (3s)
(nS) candidate
Main bkg : m+m-   m+m- e+e- that mimic (1S)e+e cos pp < 0.95
 reject e ’s faking p ’s
Electron ID
 h = K case
Kaon ID
(conversions)
Remark: Looser than (4S)  (1S) p+p- analysis
Crosschecks w/ (4S) and (3S)
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 32
e+e-  (nS)h+h- at 10.87 GeV
Signal box to optimize on background
21.7 fb-1
3S
2S
1S
m+m-[→ e+e-]
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 33
Results
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 34
“(5S)”  (1S)p+p-, (2S)p+p(2S)p+p3S
“(5S)”
3S
2S
4S
1S
(4S)  (1S) p+p-
Striking !
(1S)p+p-
2S
3S
4S
2S
4S
“(5S)”
3S
>
Expect to vanish
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 35
Remarks
e+e-  (1S)p+p4S
2S
“(5S)”
3S
>
some other reflection ?
 Structure at ~ 0.84 GeV/c2 below 3S:
“(5S)” → (2S) p+p↳ (1S) + X0
 “(5S)”: single ECM energy at 10.87 GeV
No clear indication of radiative tail
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 36
(3S)p+p-
3.2s
“(5S)”  (nS)p+p-, (1S)K+KSignal box to optimize on background
(2S)p+p-
14 s
(1S)p+p-
20 s
square box gives ~ 3.9 s
(1S)K+K-
4.9s
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 37
Yield: Unbinned extended ML Fit
signal
yield
bkg
yield
(1S)p+p-
signal PDF
[two Gaussians
20
325+-19
10.5+-4.0
3.3
3.2s
New (5S) decays from Belle
[linear ⇐ optimze box
(2S)p+p- 186 15
14s
20s
(3S)p+p-
bkg PDF
(1S)K+K- 20.2+-5.2
4.5
George W.S. Hou (NTU)
4.9s
NTHU HEP, 11/08/2007 38
M(pp) and cosqHel Distributions
(1S)p+p-
(2S)p+p-
phase space
Brown-Cahn Model
cosqHel
CLEO’07
Efficiency estimate: re-weighted MC according to data
N.B. other two modes use B-C model due to limited statistics
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 39
Systematic Uncertainty
(1S)p+p-
Source
(2S)p+p- (3S)p+p- (1S)K+K-
Tracking
4.1%
4.6%
5.6%
4.1%
Lepton Ident.
1.0%
1.0%
1.0%
1.0%
Electron rejection
0.2%
0.2%
0.4%
3.6%
Fitting
pp model
1.5%
4.4%
3.7%
6.8%
1.7%
3.2%
1.4%
13.6%
M(mmpp) selection
2.6%
2.6%
2.6%
2.6%
Bhabha rejection
1.9%
1.9%
1.9%
1.9%
Trigger
0.9%
3.1%
4.5%
1.0%
Luminosity
1.4%
1.4%
1.4%
1.4%
Cross-section
5.0%
5.0%
5.0%
5.0%
(nS) → mm bf
2.0%
8.8%
9.6%
2.0%
Total
9.0%
14.4%
14.0%
16.1%
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 40
Summary Table
Assume “(5S)” = (5S)
PDG value taken for (nS) properties
N.B. Resonance cross section 0.302 ± 0.015 nb at 10.87 GeV
PRD 98, 052001 (2007) [Belle]
Cf
(2S)  (1S)p+p(3S)
(4S)
~ 6 keV
0.9 keV
1.8 keV
• Echoes Y(4260)
Need Mechanism
• Is this (5S), or the Yb state?
Need Scan to tell
N.B. G(5S)  e+e- ≃ 0.13 keV normal
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 41
Discussion
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 42
Scan ?
~ 8 fb-1
PRL 98, 052001 (2007)
6/2005 “scan”
5 points,
30 pb-1 each
Yb!?
(stat error)
fit with
G = 110 MeV
10.75
10.8
10.85
10.9
10.95
11.0
Compare (1S)p+p-, (2S)p+p- vs Hadrons
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 43
Certainly “Anomalous” !
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 44
More Y’s from BaBar and Belle
Y(4320)
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 45
Two Y’s ?
Y(4360) = Y(4320) ?
Y(4660) !
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 46
Scan ?
~ 8 fb-1
PRL 98, 052001 (2007)
6/2005 “scan”
5 points,
30 pb-1 each
Yb!?
(stat error)
fit with
G = 110 MeV
10.75
10.8
10.85
10.9
10.95
11.0
Compare (1S)p+p-, (2S)p+p- vs Hadrons
Scan could uncover richer structure !
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 47
Corrected (4S)  (1S)p+p477 fb-1
43.9 7.9
Uncover from this study
- Data and signal yield correct
- Efficiency estimate for signal
normalization was wrong
New preliminary Result:
112 fb-1
93+-11 56
18
-4
Bf = 1.06+0.
±
0.09
10
-0. 17
37
Γ = 2.17 +0.
-0. 35± 0.33 keV
• Based on new data skim
(112 fb-1) w/ 4x efficiency
• Now consistent w/ BaBar
Revised publication
coming soon
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 48
Summary
• Observation of “(5S)” 
Evidence for
arXiv:0710.2577
(1S)p+p-, (2S)p+p-
“(5S)”  (3S)p+p-, (1S)K+K-
• Assuming (5S) properties,
B((5S)  (1S)p+p-) = 0.53 0.03 0.05 %
B((5S)  (2S)p+p-) = 0.78 0.06 0.11 %
0. 18
B((5S)  (3S)p+p-) = 0.48+-0.
15  0.07 %
0. 016
B((5S)  (1S)K+K-) = 0.061+-0.
014  0.010 %
w/ partial widths 0.52 – 0.85 MeV ⇐ Very Large
Cf. ~ 0.018 MeV for (4S)  (1S)p+p-
• New preliminary Bf for (4S)  (1S)p+pNew (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 49
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 50
New (5S) decays from Belle
George W.S. Hou (NTU)
NTHU HEP, 11/08/2007 51