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New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 1
Observation of Anomalous e+e (nS) h+h
Production at (5S) Energies
November 8, 2007, HEP Seminar @ NTHU
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 3
Outline
• Motivation
• (4S), (3S) (1S) + Template
• Dataset on (5S)
• Event Selection for (nS) h+h
• Results
• Discussion
• Summary All Results Pre
liminary
Preliminary
arXiv:0710.2577
To be submitted soon to PRL
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 4
Motivation
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 5
Motivation I: because it’s there
ee ≃ 0.27 keV
ee ≃ 0.13 keV
≃ 110 MeV ≃ 20.5 MeV
Belle has ~ 20 fb1 (5S) data
expect limits only ...
11020.5
~ 1.7 x 105
477 fb1
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 6
Motivation II: Enhancement?
PRD 74, 017504 (2006)
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 7
Motivation II: Enhancement?
PRD 74, 017504 (2006)Conceived during FPCP2006April ’06 in Vancouver
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 8
Motivation of Motivation
I sat through this
SLAC Expt’l Seminar ...
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 9
Motivation of Motivation
Shuwei YE
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 10
Motivation II: Enhancement?Y
(426
0)
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 11
Shuwei YE
Note to myself~ 7/13/05
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
Shuwei YE
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 15
Xb/Yb George W.S. Hou (NTU) ICHEP’06, 7/28/06 11
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 Could show up in ISR on (5S)(5S)- 10900 – 11000 MeV (Juge, Kuti, Morningstar)
Predicted ccg state ~ 4260➯ Prefers Higher Energy ScanPrefers Higher Energy Scan
Width: 100 MeV (~ Yc = Y(4260)) plausible
Product BR:
Assume
~
Could be smaller or larger
Guestimates
BaBar/CLEO
─
─
─
10865
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 16
Motivation II: Enhancement?
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 17
Backdrop: Data on (5S)
• 1985: CUSB, CLEO @ CESR ~ 116 pb
• 2003: CLEO III @ CESR ~ 0.42 fb1
• June 2005: Belle @ KEKB ~ 1.86 fb1 engineering run
• June 9-31, 2006: Belle @ KEKB ≅ 21.7 fb1
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 18
1.86 fb1 (2S) (3S) (4S) (5S)
Rough study ~ 9/2006 (post summer)
Hint of events above background
Took a year to analyze 21.7 fbTook a year to analyze 21.7 fb11, solely because of “computing”., solely because of “computing”.
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 19
(3S), (4S) (1S) + Template
Old subject
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 20
(3S) (1S) + Understanding
2.9 fb1
1.14 fb1
PRD 7575, 072001 (2007)
(for (3S) + + nothing)
PRL 9898, 132001 (2007)
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 21
(3S)(1S)
(2S)(1S)
(3S)(2S)
3S3S
2S2S
1S1S
More can be done at Belle ...
528 ± 24
1315 ± 39
4556 ± 70
Data from (3S) Run
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 22
(2S)(1S) (3S)(1S)
(3S)(2S)
Brown-Cahn Model
Brown-Cahn Model Moxhay Model
CLEO Model
PRD 7575, 072001 (2007)☞ allow E
E term !
Much betterdata than CLEO
CLEO Model CLEO Model
CLEO Model
Data from (3S) Run
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 23
(4S) (1S) + Template
2S3S
4S
477 fb1
211 fb1
PRD 7575, 071103(R) (2007)
PRL 9696, 232001 (2006)
~ 104
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 24
(2S)(1S) (3S)(1S)
(4S)(1S)
CLEO Model CLEO Model
Brown-Cahn Model
Data on (4S)
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 25
(3S), (4S) (1S) + Template
Published papers by Belle, BaBar and CLEOSo, (5S) straightforward.
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 26
Dataset on (5S)
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 27
14 countries, 55 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
BINPChiba U.U. of CincinnatiEwha Womans U.
Fu-Jen Catholic U.Fu-Jen Catholic U.U. of GiessenGyeongsang Nat’l U.Hanyang U.U. of HawaiiHiroshima Tech.IHEP, BeijingIHEP, Moscow
Nagoya U.Nara Women’s U.
National Central U.National Central U.
National Taiwan U.National Taiwan U.
National United U.National United U.Nihon Dental CollegeNiigata U.Nova GoricaOsaka U.Osaka City U.Panjab U.Peking U.Princeton 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.INFN TorinoToyama Nat’l CollegeVPIYonsei U.
International Collaboration: BelleInternational Collaboration: Belle
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 28
e+ source
Ares RF cavity
Belle detector
World record: L = 1.7118 x 1034/cm2/sec
SCC RF(HER)
ARES(LER)
8 x 3.5 GeV 22 mrad crossing
~ 1 km in diameter
Mt. Tsukuba
KEKBBelle
since 1999
First successful op. of Crab cavities
The KEKB ColliderThe KEKB Collider
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 29
/ KL detection
14/15 lyr. RPC+Fe
Central Drift Chambersmall cell +He/C2H6
CsI(Tl)
Aerogel Cherenkov Counter n=1.015~1.030
Si Vertex Detector3(4) lyr. DSSD
TOF
SC Solenoid1.5T
8 GeV e
3.5 GeV e16X
ACC (PID)
ECL
SVD
KLM
CDC
Belle DetectorBelle Detector
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 30
Dataset on (5S) Main Purpose
e.g.
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 31
Event Selection for (nS) h+h
h = , K
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 32
Event Selection for (nS) h+h
Track Prompt: within 5 cm of IP in z (beam direction) 1 cm in transverse
hh
X0
Muon ID; loose h = , K No other charged tracks with pT > 100 MeV/c2
|M( - M((nS))| < 150 MeV/c2 (3) (nS) candidate
cos < 0.95 reject e
’s faking ’s
Electron ID
h = K case Kaon ID
Main bkg : Main bkg : ++ ++
ee++ee that mimic that mimic (1S)e(1S)e++ee (conversions)
Remark: Looser than (4S) (1S) + analysis Crosschecks w/ (4S) and (3S)
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 33
[→ ee
3S3S
2S2S
1S1S
21.7 fb1
e+e (nS) h+hat 10.87 GeV
Signal box to optimize on background
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 34
Results
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 35
2S
3S
4S2S3S
4S
(4S) (1S) +
Expect to vanish
“(5S)” (1S) +, (2S) +
(2S) +
3S 4S>
““(5S)”(5S)”
““(5S)”(5S)”
(1S) +
Striking ! Striking !
1S1S
2S2S
3S3S
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 36
RemarksRemarks
Structure at ~ 0.84 GeV/c2 below 3S: “(5S)” → (2S) +
↳ (1S) + X
““(5S)”(5S)” : single ECM energy at 10.87 GeV No clear indication of radiative tail
2S
3S
4S
e+e (1S) +
>
““(5S)”(5S)”
some other reflection ?
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 37
“(5S)” (nS) +, (1S) K+K
(1S) +
(2S) +
(3S)(3S) ++
(1S)(1S) KK++KK
3.2
square box gives ~ 3.9
14
20
4.9
Signal box to optimize on background
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 38
Yield: Unbinned extended ML Fit
signalyield
bkgyield
signal PDF[two Gaussians
bkg PDF[linear [linear ⇐ ⇐ optimze boxoptimze box
2019325
5.24.520.2
15186
4.03.310.5
20 14
4.9 3.2
(1S) + (2S) +
(1S) K+K(3S) +
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 39
Brown-Cahn Model
phase space
M() and cos Hel Distributions
(1S) + (2S) +
Efficiency estimate: re-weighted MC according to data
N.B. other two modes use B-C model due to limited statistics
cos Hel
CLEO’07
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 40
Systematic Uncertainty
SourceSource (1S) +(2S) +(3S) +(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 1.5% 3.7% 1.7% 1.4% model 4.4% 6.8% 3.2% 13.6%
M() 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) → 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 41
Summary Table
N.B. Resonance cross section 0.302 ± 0.015 nb at 10.87 GeV PRD 98, 052001 (2007) [Belle] Cf
(2S) (1S) ~ 6 keV (3S) 0.9 keV (4S) 1.8 keV
• Echoes Y(4260) Need Mechanism
• Is this (5S), or the Yb state?
Assume “(5S)” = (5S)PDG value taken for (nS) properties
Need Scan to tellN.B.(5S) ee 0.13 keV≃ normal
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 42
Discussion
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 43
Scan ?Scan ?
YYbb!?!?
10.75 10.8 10.85 10.9 10.95 11.0
PRL 9898, 052001 (2007)
6/2005 “scan”5 points,30 pb each (stat error)
fit with = 110 MeV
~ 8 fb~ 8 fb
Compare (1S) +,(2S) +vs Hadrons
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 44
No Indication !
No Indication !
Certainly “Anomalous” !
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 45
Y(4320)Y(4320)
More Y’s from BaBar and Belle
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 46
Y(4360)Y(4360) == Y(4320) ?Y(4320) ?
Y(4660) !Y(4660) !
Two Y’s ?Two Y’s ?
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 47
Scan ?Scan ?
Compare (1S) +,(2S) +vs Hadrons
YYbb!?!?
10.75 10.8 10.85 10.9 10.95 11.0
PRL 9898, 052001 (2007)
6/2005 “scan”5 points,30 pb each (stat error)
fit with = 110 MeV
~ 8 fb~ 8 fb
Scan could uncover richer structure !
New (5S) decays from Belle George W.S. Hou (NTU) NTHU HEP, 11/08/2007 48
477 fb1
Corrected (4S) (1S) +
7.943.9Uncover from this study - Data and signal yield correct - Efficiency estimate for signal normalization was wrong
161593
112 fb
New preliminary Result:4+0.18
0.17
10 0.091.06 ±=Bf
keV 0.332.17Γ ± +0.370.35=
• Based on new data skim (112 fb) 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 49
• Observation of “(5S)” (1S) +, (2S) +
Evidence for “(5S)” (3S) +, (1S) K+K
• Assuming (5S) properties ,
B((5S) (1S) +) =
B((5S) (2S) +) =
B((5S) (3S) +) =
B((5S) (1S) K+K) =
w/ partial widths 0.52 – 0.85 MeV ⇐ Very Large
• New preliminary Bf for (4S) (1S) +
Summary
% 0.050.030.53
% 0.110.060.78
% 0.070.480.180.15
% 0.0100.0610.0160.014
arXiv:0710.2577
Cf. ~ 0.018 MeV for (4S) (1S) +
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