New Result on (5S) Decay from Belle Observation of “(5S)”  (1S) p+p-, (2S) p+p- October 8, 2007, Hadron07 @ Frascati

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

(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

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

Motivation II: Enhancement? PRD 74, 017504 (2006)

Motivation II: Enhancement? Y(4260)

Motivation II: Enhancement?

(4S), (3S)  (1S) p+p- Template

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

(3S)  (1S) p+p- Understanding 2.9 fb-1 arXiv:0706.2317 1.14 fb-1

Dataset on (5S)

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

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 = 1.7118 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

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

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

Dataset on (5S) Main Purpose e.g.

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

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)

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-]

Results

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

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 10.87 GeV No clear indication of radiative tail

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

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

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

PDG value taken for (nS) properties 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- ~ 6 keV (3S) 0.9 keV (4S) 1.8 keV Echoes Y(4260) Need Mechanism Is this (5S), or theYb state? Need Scan to tell N.B. G(5S)  e+e- normal

Discussion

Systematic Uncertainty Source (1S) p+p- (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 1.5% 3.7% 1.7% 1.4% pp model 4.4% 6.8% 3.2% 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%

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

Cf. ~ 0.018 MeV for (4S)  (1S) p+p- Summary arXiv:0710.2577 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. ~ 0.018 MeV for (4S)  (1S) p+p-