1. Charmonium decays in Two-Photon process at Belle
H. Nakazawa (KEK)
Nov 26, 2007
BES-Belle-CLEO-BaBar
Joint Workshop on Charm Physics

2. Charmonia in Two-Photon Process at BelleX g
With large flux
Good test for QCD
Cross section for hadron pair
C-even resonance
KEKB
No-tag method: Use of
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

3. Charmonia in Two-Photon Process at Bellegg c 2 g y J
32.6/fb
PLB540(2002)
Nevents
136.0±13.3
ГγγBr [eV]
13.5±1.3±1.1
Гγγ [keV]
0.56±0.06±0.05±0.03
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

4. Charmonia in Two-Photon Process at Belle+ p , K g
87.7/fb
PLB615(2005)
N evt
BrГγγ(eV)
χc0->
153±17
14.3±1.6±2.3
129±18
15.1±2.1±2.3
χc2->
33±8
0.44±0.11±0.07
54±10
0.76±0.14±0.11 - + p K
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

5. g ® K S S ) ( - + p M 397.6/fb PLB651(2007) t N evt BrГγγ(keV)
Ks resolution 4MeV
Satisfies Isospin invariance
Ggg keV, keV
N evt
BrГγγ(keV)
BrГγγ (KsKs)/BrГγγ(K+K-)
χc0
141±13
7.00±0.65±0.71
0.49±0.07±0.09
χc2
37±6
0.31±0.05±0.03
0.70±0.21±0.13
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

6. BrГγγ(π0π0) /BrГγγ(π+π-)p g
95/fb
Presented at
PHOTON2007
11:05 tomorrow
γγ→ππ
S.Uehara
N evt
BrГγγ(eV)
BrГγγ(π0π0) /BrГγγ(π+π-)
χc0
35.3±9.2(4.5σ)
8.4±2.2±0.8
0.56±0.16±0.10
χc2
8.2±6.4(1.4σ)
0.29±0.23±0.03
0.38±0.16±0.07
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

7. Charmonia in Two-Photon Process at Belleg
p p
89/fb
PLB621(2005)
N evt
BrГγγ[eV]
Гγγ[keV] ηc
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

8. Charmonia in Two-Photon Process at Belle) 1 ( , g ( L ) M vs S ) (
vsM M g p L S -
464/fb
Hep-ex
(2005)
of inclusive
of candidates
of inclusive
of candidates
Ptbはただのprojection?
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

9. Charmonia in Two-Photon Process at Belleg L L S S , ( 2 ) S c h
Missing g g L c h
Prelim.
上下エラーどやった N
are not consistent with diquark prediction of
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

10. Charmonia in Two-Photon Process at Belle
Observation of candidate in D g 2 c D - +
395/fb
PRL96(2006) S p t
Bg in ptb
D+D-は細い
Chi’c0はDdbarのした？
Shade D+SB
Open SB+SB
Nevents
64±18(5.3σ)
Mass [MeV/c2]
3929±5±2
Г[MeV]
29±10±2
ГγγBr [keV]
0.18±0.05±0.03
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

11. Charmonia in Two-Photon Process at Belle
Observation of (2P) candidate in c g g D D c 2
J=2
J=0
Continuum
1.9/9 J=2 lam=2
23.4/9 J=0
SB 33 ev
Gggの予言
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

12. Charmonia in Two-Photon Process at Belle
2K2p, 4K g
4p,
(1)
395/fb
Submitted to EPJC
arXiv:
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

13. Charmonia in Two-Photon Process at Belle
2K2p, 4K g
4p,
(2)
Fits to higher invariant mass region
No clear signal for ηc’ found
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

14. Charmonia in Two-Photon Process at Belle
2K2p, 4K g
4p,
(2)
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

15. Charmonia in Two-Photon Process at Belle
2K2p, 4K g
4p,
(3)
Two-body decays with ρ0, K*0, f2(1270), f2’(1575)
f2f2→4π
f2f2’→2K2π
ρ0ρ0→4π
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

16. Charmonia in Two-Photon Process at Belle
2K2p, 4K g
4p,
(3)
G=ΓγγBr
Indirect G(X) =
Br(X)G(R→A)/Br(R→A)
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

17. Charmonia in Two-Photon Process at Belleg c m p K S ) (
(1)
483/fb
Presented at
PHOTON2007
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

18. Charmonia in Two-Photon Process at Belle) ( c h g m p K S 1S 2S
Nevent
Belle (483/fb)
CLEO (26.7/fb)
BaBar (88/fb)
4488±100
2547±90
592±48
174±28
112±24
Mass [MeV]
Belle
CLEO
BaBar]
PDG
2981.3±0.5±0.4
±1.3 ± 1.5
±1.1 ±0.9
±1.2
3634.9±2.3±1.0
3642.9±3.1±1.5
3630.8±3.4±1.0
3637±4
Width [MeV]
BaBar
33.0±1.4±1.0
24.8±3.4±3.5
34.3±2.3±0.9
25.5±3.4
21.4±6.4±4.7
6.3±12.4±4.0
17.0±8.3±2.5
14±7
ΓγγBr [eV]
142.4±3.8 ±15.1
135.7±7.3 ±9.2
13.0±2.2±2.0
24.4±6.8±2.7
Γγγ [keV]
7.5±0.2±0.8±1.3
7.1±0.4 ±0.5 ±2.0
6.7±0.9
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

19. Charmonia in Two-Photon Process at Belle
Summary
C-even Charmonia ηc, ηc’, χc0, χc2 measured in various two-photon modes
χc2(2P) candidate observed
New modes ηc→Σ0Σ0, f2f2’ seen
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

20. Charmonia in Two-Photon Process at Belle
menu
Mode
W[GeV]
Data[/fb]
charmonium
395
QCD
397.6
460
85.9
Tesor Meson 26 D g S K g S L , g
上下を中央に - + p g f )
980 ( p g - +
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

21. Charmonia in Two-Photon Process at Belle
Systematic Errors (%)
Гγγ Μ Г 1S 2S
tracking 4
Ks ID 1
Luminosity function 5
Integrated Luminosity
Trigger Efficiency
Fit Range
0.1(0.1)
1(3)
---
0.01(0.01)
2.7(0)
0(3)
Bg function
4.0(4.0)
18(17)
1.8(1.8)
10(21)
J/psi
0.3(0.3)
MC Mass shift
Pt-balance cut
1.0(1.8)
1(14)
0.05(0.05)
1.4(0.4)
17(18)
Mass resolution
0.7(0.6)
1(2)
2.9(0.9)
7(7)
Total
9.7(9.7)
20(24)
0.06(0.05)
4.3(2.0)
21(29)
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

22. Charmonia in Two-Photon Process at BelleK g
(2) BC
DKV
σ0(KSKS)/σ0(K+K-) approaches BC as W→∞
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

23. Charmonia in Two-Photon Process at Belle
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

24. Charmonia in Two-Photon Process at Belle
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

25. Charmonia in Two-Photon Process at Belle
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

26. Charmonia in Two-Photon Process at Belle
(ECL)
(SVD)
(ACC)
(KLM)
(CDC)
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

27. Charmonia in Two-Photon Process at Belle
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

28. Charmonia in Two-Photon Process at Belle
QCD calculations for Hadron Pair Production
BL:Brodsky & Lepage PRD24,2848(1981)
BC:Benayoun & Chernyak NPB329,285(1990)
meson
baryon
DKV:Diehl et al. PLB532,99(2002)
Handbag Model
meson
baryon
QCD vs hyperon Xsec
Ppbarだけでも
Diquark Model
Kroll et al. PLB316,546(1993)
Berger et al. EPJ C28,249(2003)
Nov 26, 2007
Charmonia in Two-Photon Process at Belle

29. Charmonia in Two-Photon Process at Belle
Nov 26, 2007
Charmonia in Two-Photon Process at Belle