1. 新强子态 New types of hadrons 高能所 北京 Stephen Olsen &
夏威夷 大学
&
高能所 北京
新强子态
New types of hadrons
HEP10 南京大学 April 26, 2008

2. Constituent Quark Model (CQM)
Gell-Mann
(& 6 antiquarks)
6 quarks
Zweig
u-2/3
c-2/3
t-2/3
u+2/3
c+2/3
t+2/3
b+1/3
s+1/3
d-1/3
s-1/3
b-1/3
d+1/3
Baryons: qqq
Mesons: q q
u+2/3
u+2/3 p:
u+2/3
d-1/3
p+ :
d+1//3
u-2/3
U-2/3
u-2/3 p:
p- :
D+1/3
d-1/3

3. Fabulously successful
mesons q q

4. QCD suggests non-qq meson spectroscopies
glueball

5. Charmonium model predictions for cc mesons are robust & reliable, both for masses & transition rates. Therefore, it is an especially good system to use to search for non-qq mesons.

6. predicted
measured

7. agree with predictions
About 20 measured transition rates
D1D
D(*)D(*)
DsDs
D(*)D(*)
DsDs DD g g DD p0 pp g
pp,h,p0
measured rates all
agree with predictions
(more-or-less) g g g

8. About 20 measured transition rates
D1D
D(*)D(*)
DsDs
D(*)D(*)
DsDs DD g g DD p0 pp g
pp,h,p0
G(pp-allowed) 50~ 100keV
G(p – ispin viol)~0.5 keV
G(E1-gamma) 20~200 keV
G(M1-gamma)~1keV
G(D(*)D(*)) ≥ 10 MeV g g g

9. I’ll emphasize recent results.

10. X(3872)
ppX + p+p-J/y
X(3872)
B±K±p+p-J/y y’ y’ y’
X(3872)
X(3872)

11. M(pp) looks like rpp Belle & CDF: JPC = 1++  most likely
PRL
c2/dof = 43/39 (CL=28%)
kinematic
limit≈mr
Belle & CDF: JPC = 1++  most likely
= 2-+  still possible

12. X(3872) properties (PDG2007)
MeV
MD0 + MD*0 = ± 0.4 MeV

13. What is it? c c cc1’ charmonium? L Maiani et al T-W Chiu & TH Hsieh
PRD 71, (2005)
T-W Chiu & TH Hsieh
PRD 73, (2006)
D Ebert et al
PLB 634, 214 (2006) … c c
C Meng & KT Chao
PRD 75, (2007)
cc1’ charmonium?
NA Tornqvist
PLB 590, 209 (2004)
ES Swanson
PLB 598,197 (2004)
E Braaten & T Kusunoki
PRD (2004)
CY Wong
PRC 69, (2004)
MB Voloshin
PLB 579, 316 (2004)
F Close & P Page
PLB 578,119 (2004) …
too light??
P Lacock et al (UKQCD)
PLB 401, 308 (1997)

14. Is X(3872) a Charmonium state??? ??
3872MeV

15. Could the X(3872) be the cc1’ (23P1)???
3872MeV
Mass is too low
cc1’ppJ/y violates Ispin
G(gJ/y) should be >>G{rJ/y)
expt: G(gJ/y) <<G(rJ/y)

16. Could the X(3872) be the hc2 (11D2)???
3872MeV
hc2’ppJ/y violates Ispin
G(gJ/y) should be very small
expt: G(gJ/y) 0.1 G(rJ/y)
BKhc2 should be very small

17. Is X(3872) a diquark-diantiquark?
Where are the “partner states”?
Xu(3872)
Xd(3872)
X+(3872)
X-(3872) u d c c u d c c c c d u c c u d
BaBar:
B+K-Xu
B0K0Xd
Bf(B0K-X+)Bf(X+p+p0J/y)
< 0.4
M(Xd)-M(Xu)= 2(md-mu)/cosq
Bf(B-K-X0)Bf(X+p+p-J/y)
 8 ± 3 MeV
(expected value is  2)
L Maiani et al PRD 71, (20050
PRD 71, (2005)

18. BKSX & BK±X comparison
BaBar
K± mode
K± mode
KS mode
KS mode
DM = 0.22 ± 0.90 ± MeV
Compared to 8±3 MeV
(Maiani et al PRD )
DM = 2.7 ± 1.6 ± 0.4 MeV

19. X(3872)D0D*0? BaBar & Belle see a DD* threshold enhancement in BKDD*
G. Gokhroo et al. (Belle)
D0D0p0
B. Aubert et al. (BaBar) Phys. Rev. D77, (2008)
Both groups see a high mass value
& a Bf(DD*)  10x Bf(p+p-J/y)
“DD* molecular” models
Predicted Bf(DDp)  0.1Bf(p+p-J/y)
(c.f. E.S. Swanson PLB 588, 189 (2004))

20. arXiv: ” ”…

21. Still (5 yrs after discovery) no universally
accepted explanation for the X(3872).
(Although some kind of DD* molecular state
--either real or virtual-- seems most popular.)

22. The 1-- states seen in ISR

23. e+e-  gisr Y(4260) at BaBar BaBar PRL95, 142001 (2005) fitted values:
233 fb-1
M=4259  8 +2 MeV
G = 88  MeV -6 -9
Y(4260)

24. Not seen in e+e-  hadrons
J.Z.Bai et al (BES), PRL 88, (2006)
s(e+e- hadrons)
s(e+e-  m+m-)
huge by charmonium
standards
BES data
4260
G(Y4260p+p- J/y) > 90% CL
X.H. Mo et al, PL B640, 182 (2006)

25. “Y(4260)” at Belle (New) BaBar values: M=4247  12 +17 MeV -32
G = 108  19 ±10 MeV
-32
M=4259  8 +2 MeV
G = 88  MeV -6 -9
M=4008  MeV
G = 226  44 ±87 MeV
-28
???
Resonance?
Thresh effect? …?
C.Z Yuan et al (Belle)
arXiv:
PRL 99,

26. No 1-- cc slot for the Y(4260)
X.H. Mo et al, hep-ex/
4260
4260

27. Is the Y(4260) a cc-gluon hybrid?
qq-gluon excitations predicted 30 yrs ago
lowest 1-- cc-gluon mass expected at ~4.3 GeV
relevant open charm threshold is D**D (~4.28 GeV)
G(ppJ/y) larger than that for normal charmonium
G(e+e-) smaller than that for ordinary charmonium
Horn & Mandula PRD 17, 898 (1977)
Y(4260) seems to match all of these!!!
Banner et al, PRD 56, 7039 (1997); Mei & Luo, IJMPA 18, (2003)
Isgur, Koloski & Paton PRL 54, 869 (1985)
McNeile, Michael & Pennanen PRD 65, (2002)
Close & Page NP B443, 233 (1995)

28. DD** thresholds in & “Y(4260)”
D** spectrum
D1D
No obvious
distortions
4.28-mD
M(p+p-J/y) GeV

29. BaBar’s p+p-y’ peak at 4325MeV
D2D
298 fb-1 (BaBar) hep-ex/
D1D
e+e-gISR p+p- y’
Nevt = 68 (<5.7 GeV/c2)
Nbkg = 3.1 1.0
M=4324  24 MeV
G = 172  33 MeV
above all D**D
thresholds
Not Compatible with the Y(4260)
2-prob
< 5.7 GeV/c2
Y(4260)
6.5 10-3
(4415)
1.2 10-13
Y(4320)
29%
BaBar PRL (2007)
S.W.Ye QWG-2006 June 2006

30. 4325 MeV p+p-y’ peak in Belle (new)
Two peaks!
(both relatively narrow)
(& both above D**D thresh)
(& neither consistent with 4260)
M=4361  9 ±9 MeV
G = 74  15 ±10 MeV
M=4664  11 ±5 MeV
G = 48  15 ±3 MeV
BaBar values
4260
X.L. Wang et al (Belle)
arXiv:
PRL 99, (2007)
M=4324  24 MeV
G = 172  33 MeV
548 fb-1

31. Y(4360) & Y(4660) are above all D**D thresholds
D** spectrum
4.66-mD
4.36-mD

32. No sign of Y(4360) or Y(4660) in e+e-  D(*)D(*) or DDp
DD+DD*+D*D*+DDp
Pakhlova (Belle) PRL 98, (2007)

33. The Y(4260) looks like a hybrid
But the Y(4360) and Y(4660)
-which look like the Y(4260)-
do not look like hybrids.

34. Recent News
electrically
charged!!

35. M(p±y’) from BK p± y’ M2(py’) GeV2 M(py’) GeV M2(Kp) GeV2
M = 4433 ±4 ±1 MeV
Gtot = MeV
Nsig =124 ± 31evts
K*Kp
Veto
Veto
K2*Kp?
-13
-11
M2(py’) GeV2
6.5 
M(py’) GeV
M2(Kp) GeV2
S.-K. Choi et al (Belle)
arXiv:
PRL weeks ago

36. Comments on the Z+(4430) Not a reflection from the Kp system
(see backup slides) ~
No significant signal in B KpJ/y
It has non-zero charge  not cc or hybrid c c
charmonium
Mass, width & decay pattern similar to Y(4360) & Y(4660)

37. comments
There seems to be a new hadron spectroscopy in the M=3.5~5 GeV region
Maybe more than one
Bodes well for BESIII, Super-B factories & PANDA
Some states are narrow even though they are far above decay thresholds
e.g. Y(4660)ppy’ & Z+(4430)p+ y’ have large Q but G≈50 MeV
characterized by large partial widths (Bfs) to hadrons+J/y (or y’)
Br(X(3872)rJ/y) > 4.3% (Isospin=1)
G(Y(4260)p+p-J/y) > 1.6 MeV
G(Z(4430)py’) > 1 MeV
States that decay to y’ not seen decaying to J/y (and vice-versa)
Bf(Y(4660)ppy’) >> Bf(y(4660)ppJ/y)  same for Y(4360)
Z(4430)py’ seen but pJ/y not reported
Y(4260) not seen in Y(4260)ppy’
The new 1-- states are not apparent in e+e-D(*)D(*) cross sections
There are no evident changes at the D**D mass threshold

38. New 1-- states p+p- J/y p+p- y’ K+K- J/y
C.-Z. Yuan et al (Belle) PRD 77, ® (2008)

39. some of the states are near thresholds,
DD thresholds
DSDS thresholds
some of the states are near thresholds,
but this is not a universal feature

40. Are there XYZ counterparts in the ss- & bb- systems?

41. Belle: G((5S)pp(nS))
is Huge!!!
(4S)pp(1S)
477 fb-1 from Belle
(1/20 times the data &
~1/10th the crosssection)
8 times as many events! 2S 3S 4S
(4S)  (1S) p+p-
“(5S)”pp(1S)
23.6 fb-1 from Belle
325±20 evts!
44±8 evts
Belle
K.F. Chen et al (Belle)
PRL 100, (2008)
(4 weeks ago)

42. PDG value taken for (nS) properties
Partial Widths
Assume “(5S)” = (5S)
PDG value taken for (nS) properties
N.B. Resonance cross section ± nb at GeV
PRD 98, (2007) [Belle]
>100 times bigger!! Cf
(2S)  (1S) p+p- ~ 6 keV
(3S) keV
(4S) keV

43. If there are bb versions of the XYZ’s, why not ss versions as well?
It looks like there is a bb version of the Y(4260) lurking around the (5S)
W.-S. Hou PRD 74, (2007)
If there are bb versions of the XYZ’s,
why not ss versions as well?

44. 1-- Ys states around 2 GeV? Y(2175)f0(980)f from BaBar
confirmed by BESII
in J/y  h f f0(980)
Y(2175)f0(980)f
from BaBar
e+e-  g f0(980)h
@ Ecm ~10.6 GeV
M(f0(980)f GeV
M.Ablikim et al (BES)
PRL 100, (2008)
6 weeks ago

45. Maybe the X(1835) is one too? J/ygX(1835) | p+p-h’ mostly ss X(1835)
M. Ablikim et al (BESII), Phys.Rev.Lett.95:262001,2005

46. Luciano had-2007

47. Now it looks like there may also be XYZ-like
spectroscopies for the s- & b-quark sectors
Implications for BES-III:
J/y (y’) running: systematic study of
states decaying to f & h’
Higher energies: look for states decaying
to lower charmonia (hc, J/y, cc1 etc.) …

48. Lots of pieces Are they all from the same puzzle? Y(3940) Z(4430)
X(3940)
Are they all from the same puzzle?
X(4160)
Y(4660)
Y(4050)
Y(4260)
Y(4360)
X(3872)

49. 謝謝

50. Backup Slides

52. B-factories produce lots of cc pairs
0-+, 0++, 2++
1- - only
C =+ states

53. Could Z(4430) be a reflection from the Kp channel?

54. Cos qp vs M2(py’) p qp +1.0 M2(py’) cosqp -1.0K
+1.0
22 GeV2
(4.43)2GeV2
0.25
M2(py’)
cosqp
16 GeV2
-1.0
M (py’) & cosqp are tightly correlated;
a peak in cosqp  peak in M(py’)

55. Can interference between Kp partial waves produce a peak?
Only S-, P- and D-waves seen in data
interfere
Add incoherently

56. Can we make a peak at cosqp≈0.25 with only S-, P- & D-waves?
Not without introducing other, even more dramatic
features at other cosqp (&,, other Mpy’) values.

57. Talk outline Y(3940) X(3940) Y(4260) X(4160) Z(4430) X(3872) Y(4660)