1. Recent Results from Ψ(2S) and χcJ Decays
平荣刚
IHEP, Beijing
for the BES Collaboration
中国物理学会2006年秋季会议
CPS2006,Sept , 2006, Beijing Ping Rong-Gang
ICHEP06,July 26 - August 2, 2006

2. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
ICHEP06,July 26 - August 2, 2006

3. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
Data samples
14M
2001.Nov.01to 2002.Mar.02 4M 3M
6.42 pb-1 continuum data at
Ecm=3.65 GeV for bkg study.
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

4. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang

5. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang

6. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
Data
MC+cont.+Bg.
Cont.+Bg.
Bg.
BESII:Preliminary
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

7. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
M. Appelquist and H. D. Politzer, PRL34, 43 (1975)
This is the famous (or notorious)
“12% rule”.
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

8. “12% rule” and “ puzzle”
Violation revealed by Mark-II , confirmed by BESI at higher sensitivity.
Extensively studied by BESII
VP mode:  , K*+K-+c.c., K*0K0+c.c., 0,…
PP mode: KSKL, K+K-, +-
VT mode: K*K*2, f2’, a2, f2
Multi-body: 3(+-), …
MARK-II
K*K ρπ
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

9. J/, ’ VP
BESII : PLB614, 37 (2005); PRD73, (2006)
CLEOc: PRL94, (2005)
mode
BESII:
B(’)(×10-5)
CLEOc:
PDG04/BESII/…
B(J/)(×10-4)
B(’)/B(J/)
(%) 
5.1±0.7±1.1
±0.2
234±26
0.13±0.03
(2150)
19.4±
N/A
+-0
18.1±1.8±1.9
±2.8
200±9
0.92±0.11
K*+K-+c.c.
13.3±2.7±1.7
±0.9
50±4
0.34±0.20
K*0K0+c.c.
2.9±1.7±0.4
±0.3
42±4
2.6±0.6 
±0.28
±0.2
5.38±0.66
3.7±1.2 
±0.17
±0.2
1.93±0.23
10.9±3.4
’
±0.33
1.05±0.18
18±16 
<0.40
<0.064 
3.3±1.1±0.5
±0.4
8.98±0.92
3.0±1.2
’
3.1±1.4±0.7
5.46±0.64
5.7±3.0 
<3.1
23.5±2.7
<0.53
’
±0.7
2.26±0.43
14±11

10. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
J/, ’  PP: 12% rule
BES, PRL 92, (2004)
CLEO, hep-ex/
’ (10-5)
J/ (10-4)
Qh (%)
+–
0.8±0.8±0.2 (CLEO)
90% C.L.)
1.47 ± 0.23
(PDG04)
5.4 ± 5.6
90% C.L.)
K+K–
6.3±0.6±0.3 (CLEO)
2.37 ± 0.31
26.6 ± 4.6
KSKL
5.8±0.8±0.4 (CLEO)
5.24±0.47±0.48 (BES)
5.44 ± 0.54 (average)
1.82 ± 0.13
(BES04)
31.9 ± 5.4
28.8 ± 4.2
29.9 ± 3.7
KK mode enhanced relative to the 12% rule.
Pure EM mode  not enhanced, may be suppressed.
J/  and ’ are related by ee of charmonia and  form factors.
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

11. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
’ V T
PRD69(2004)072001
VT mode
B’ X (10 – 4)
(BES-II)
B J/X (10 – 3)
(PDG2002)
Qh(%)
 f2
2.05 ±0.41 ±0.38
4.3 ±0.6
4.8 ±1.5
 a2
2.55 ±0.73 ±0.47
10.9 ±2.2
2.3 ±1.1
K* K*2
1.86 ±0.32 ±0.43
6.7 ±2.6
2.8 ±1.3
 f2'
0.44 ±0.12 ±0.11
1.23 ±0.21 †
3.6 ±1.5
† This value from DM2 only
Suppressed!!
CPS2006,Sept , 2006, Beijing Ping Rong-Gang
12 % rule

12. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
’ 3-body
PRD71,072006(2005); PRD74, (2006)
256±18
44.8±8.7
914±42
921±40
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

13. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
’ 3-body
BESII: PRD71, (2005)
BESII: PRD74, (2006)
Suppressed!!
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

14. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
Multi-body ’ decays
BESII, PRD73, (2006)
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

15. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
Multi-body ’ decays
BESII, PRD73, (2006)
Some modes are suppressed, some are enhanced, while some others obey the 12% rule!
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

16. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang

17. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang

18. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
Summary: “12%” rule
Facts:
’ VP : suppressed
’ PP : enhanced/supressed
’ VT : suppressed
Multi-body : obey/sup
Radiative : enhanced/supressed
Seems no obvious rule to categorize the suppressed, the enhanced, and the normal decay modes of J/ and ’.
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

19. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang

20. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang

21. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
Pair production of vectors
c0
c1
c2
Improved precision over PDG (BESI) results on cJKKKK and .
First measurement of cJKK.
BESII
cJ→2(K+K)
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

22. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
Pair production of vectors 38
c0 28
c2
First observation:
B(c0) = (2.290.580.41)10-3
B(c2) = (1.770.470.36)10-3
CPS2006,Sept , 2006, Beijing Ping Rong-Gang
BES: PLB630, 7 (2005)

23. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
cJ
BES: PRD73, (2006) 
c0 
Evidences for c0 and c0,2.
Agree with COM and QCM predictions.
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

24. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
Summary of the test of color octet mechanism
● For χcJ →PP, the theoretical results are in general good agreement with experimental values .
●For χc0 →B Bbar, there is no reliable theoretical interpretation. The experimental values of Br(χcJ →Λ Λbar) decays are quite larger than theo. values.
● More experimental information are desirable for determining the color octec wavefunction of χcJ states.
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

25. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
PWA on c c0! p+p-K+K-.
Motivation :
▲Compared with vector and pseudoscalar mesons, little information on scalar and tensor mesons are known.
▲ The decays of ccJ provide a direct window on studing of 0++ and 2++ mesons.
Different way for scalar study:
Start from JPC=0++, 1++, 2++
Start from gluon+gluon
Pair production of scalars, very different from J/ decays
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

26. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
c0      K  K 
BES: PRD72, (2005)
c0(3414.7±0.6MeV)
1. Qi = 0 ;
2. p()+p(  ) > 650 MeV
[BG:’   J/ ];
3. Prob(    K K )> Prob(      )&
Prob(    K K )> Prob(  K K K K );
4. M( )  [497±50] MeV/c2 & second vertex <5mm [BG: KS ];
c1(3511.3±1.3MeV)
c2(3556.4±0.9MeV)
Event level
5C-fit
1371 events
1.Avoid introducing a huge number of partial waves;
2. constrained by present statistics; our study is devoted to c0      K  K 
c0
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

27. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
(    )( K  K )
BES: PRD72, (2005)
f0(980)
f0(2200)
f0(1710)
f0(1370)
(770)
CPS2006,Sept , 2006, Beijing Ping Rong-Gang
Q. Zhao, PRD72, (2005), try to understand these data and the scalars …

28. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
BES: PRD72, (2005)
(K    )(K    )
K*(892)0
With
Kappa-kappa
Without
Kappa-kappa
S=39.
K*0/2(1430)
K*0(1950)
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

29. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
(K   )K
BES, c0→+K+K
BES: PRD72, (2005)
1371 events
K1(1270)
K1(1400)
K1(1270)
M(K ) [896±60] MeV
K1(1270)
1P1, 3P1 axial-vector-meson mixing:
1P1 : KA=cosθK1(1400)＋sinθK1(1270)
3P1 : KB=cosθK1(1270)＋sinθK1(1400)
The mixing angle between K1A and K1B >57 degrees, while in ’ decays to K1K, the angle is <29 degrees (PRL83p1918). Why?
M( ) [700,850] MeV
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

30. Summary PWA of c0      K  K 
From the c0      K  K  decay fit results, it is found that
scalar resonances have larger decay fractions compared to those
of tensors, and such decays provide a relatively clean laboratory
to study the properties of scalars, such as f0(980),f0(1370),f0(1710),
f0(2200) and so on.
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

31. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
χc1→PPP allowed by spin-parity selection rule 　
c2
c1
Event selection:
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

32. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
Nsig=418± 60 h
Nsig=222±28 (8.8s)
Nsig=58± 14 (4.5s)
h sideband
a0 sideband
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

33. χc1→PT allowed by spin-parity selection rule
c0→PPP is suppressed
by spin-parity selection;
BES: cJ→KK and 
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

34. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
PRD74, (2006)
cc0 cc1 cc2
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

35. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
Summary
Thanks a lot !
CPS2006,Sept , 2006, Beijing Ping Rong-Gang

36. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang

37. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang

38. CPS2006,Sept. 15 - 17, 2006, Beijing Ping Rong-Gang
1P1, 3P1 axial-vector-meson mixing:
Nonstranger member: strange memeber
1P1 : b1(1235): G= KA=cosθK1(1400)＋sinθK1(1270)
3P1 : a1(1260): G= KB=cosθK1(1270)＋sinθK1(1400)
　　　　　　　　　　　　　　θ ≈45°
CPS2006,Sept , 2006, Beijing Ping Rong-Gang