1. New Result on (5S) Decay from Belle
Observation of “(5S)”  (1S) p+p-, (2S) p+p-
October 8, 2007, Frascati

2. In memory of C.C. Hou (06/08 (Lunar), 1928 – 19/09, 2007)
Professor of Economics
and International Trade

3. (4S), (3S)  (1S) p+p- Template Dataset on (5S)
Outline
Motivation
(4S), (3S)  (1S) p+p- Template
Dataset on (5S)
Event Selection for (nS) h+h-
Results
Discussion
Summary
Coming Soon: arXiv:0710.????
All Results Preliminary

4. Motivation I: because it’s there
Belle has ~ 20 fb-1 (5S) data
G ≃ 20.5 MeV
G ≃ 110 MeV
Gee ≃ 0.13 keV
Gee ≃ 0.27 keV
expect limits only ...
~ 1.7 x 10-5
477 fb-1

5. Motivation II: Enhancement?
PRD 74, (2006)

6. Motivation II: Enhancement?
Y(4260)

7. Motivation II: Enhancement?

8. (4S), (3S)  (1S) p+p- Template

9. (4S)  (1S) p+p- Template
477 fb-1 2S 3S 4S
211 fb-1

10. (3S)  (1S) p+p- Understanding
2.9 fb-1
arXiv:
1.14 fb-1

11. Dataset on (5S)

12. 14 countries, 55 institutes, ~400 collaborators
International Collaboration: Belle
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.
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
14 countries, 55 institutes, ~400 collaborators

13. The KEKB Collider World record: L = 1.7118 x 1034/cm2/sec since 1999
e+ source
Ares RF
cavity
Belle detector
SCC RF(HER)
World record:
L = x 1034/cm2/sec
First successful op. of Crab cavities
ARES(LER)
~ 1 km in diameter
Mt. Tsukuba
KEKB
Belle
8 x 3.5 GeV
22 mrad crossing
since 1999

14. Belle Detector n=1.015~1.030 3.5 GeV e+ 8 GeV e- m / KL detection
ACC (PID)
Aerogel Cherenkov Counter
n=1.015~1.030
SC Solenoid
1.5T
ECL
3.5 GeV e+
CsI(Tl)
16X0
TOF
8 GeV e-
CDC
Central Drift Chamber
small cell +He/C2H6
KLM
m / KL detection
14/15 lyr. RPC+Fe
SVD
Si Vertex Detector
3(4) lyr. DSSD

15. Dataset on (5S) 1985: CLEO,CUSB @ CESR ~ 116 pb-1
PRL 54, 381 (1985)
(5S)
1985: CESR ~ 116 pb-1
2003: CLEO CESR ~ 0.42 fb-1
2005: KEKB ~ 1.86 fb-1
engineering run
2006, June 9-31: KEKB
≅ 21.7 fb-1

16. Dataset on (5S)
Main Purpose
e.g.

17. Event Selection for (nS) h+h-
h = p, K

18. 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
cos  < 0.95
reject e ’s faking  ’s
Electron ID
h = K case
Kaon ID
Main bkg : m+m-   m+m- e+e- that mimic (1S)e+e- (conversions)
Remark: Looser than (4S)  (1S) p+p- analysis
Crosschecks w/ (4S) and (3S)

19. e+e-  (nS) h+h- at 10.87 GeV 3S 2S 1S 21.7 fb-1
Signal box to optimize on background 3S 2S 1S
m+m-g[→ e+e-]

20. Results

21. “(5S)”  (1S) p+p-, (2S) p+p-
Striking !
(1S) p+p- 2S 3S 4S
“(5S)”
>
Expect vanish

22. Remarks e+e-  (1S) p+p- 4S 2S “(5S)” 3S >
Structure at ~ 0.84 GeV/c2 below 3S: “(5S)” → (2S) p+p-
↳ (1S)+X
some other reflection ?
“(5S)” : single ECM energy at GeV
No clear indication of radiative tail

23. “(5S)”  (nS) p+p-, (1S) K+K-
square box gives ~ 3.9 s
(1S) K+K-
4.9 s

24. Yield: Unbinned extended ML Fit
signal
yield
bkg
yield
signal PDF
[two Gaussians
bkg PDF
[linear ⇐ optimze box
(1S) p+p-
(2S) p+p-
14 s
20 s
(3S) p+p-
(1S) K+K-
3.2 s
4.9 s

25. M(pp) and cos qHel Distributions
(1S) p+p-
(2S) p+p-
phase space
Brown-Cahn Model
Efficiency estimate: re-weighted MC according to data
N.B. other two modes use B-C model due to limited statistics

26. PDG value taken for (nS) properties
Summary Table
Assume “(5S)” = (5S)
PDG value taken for (nS) properties
N.B. Resonance cross section ± nb at GeV
PRD 98, (2007) [Belle] Cf
(2S)  (1S) p+p- ~ 6 keV
(3S) keV
(4S) keV
Echoes Y(4260) Need Mechanism
Is this (5S), or theYb state?
Need Scan to tell
N.B. G(5S)  e+e- normal

27. Discussion

28. Systematic Uncertainty
Source (1S) p+p- (2S) p+p- (3S) p+p- (1S) K+K-
Tracking % % % %
Lepton Ident % % % %
Electron rejection 0.2% % % %
Fitting % % % %
pp model % % % %
M(mmpp) selection 2.6% % % %
Bhabha rejection 1.9% % % %
Trigger % % % %
Luminosity % % % %
Cross-section % % % %
(nS) → mm bf % % % %
Total % % % %

29. Corrected (4S)  (1S) p+p-
477 fb-1
Uncover from this study
- Data and signal yield correct
- Efficiency estimate for signal
normalization was wrong
112 fb-1
New preliminary Result:
Based on new data skim
(112 fb-1) w/ 4x efficiency
Now consistent w/ BaBar
Revised publication
coming soon

30. Cf. ~ 0.018 MeV for (4S)  (1S) p+p-
Summary
arXiv:
Observation of “(5S)”  (1S) p+p-, (2S) p+p-
Evidence for “(5S)”  (3S) p+p-, (1S) K+K-
Assuming (5S) properties ,
B((5S)  (1S) p+p-) =
B((5S)  (2S) p+p-) =
B((5S)  (3S) p+p-) =
B((5S)  (1S) K+K-) =
w/ partial widths 0.52 – 0.85 MeV ⇐ Very Large
New preliminary Bf for (4S)  (1S) p+p-
Cf. ~ MeV for (4S)  (1S) p+p-