1. BES-Belle-CLEO-BaBar WS
Z(4430)
CLEO
BES
BES-Belle-CLEO-BaBar WS
BaBar
S.L. Olsen
U of Hawaii
&
高能所 北京
Belle

2. S.Olsen
cheap!!
(美元)
性感!
mesons
mesons
笨手笨脚

3. 1st: The Z(4430)

4. Study BKp+y’ y’  ℓ+ℓ- tight PID cuts (both leptons)
Use fb-1
y’  ℓ+ℓ- tight PID cuts (both leptons)
|Mℓℓ – M y’|<20 MeV
y’ p+p-J/y: Mp+p->0.45 GeV;
|Mp+p-l+l- -Ml+l GeV| < GeV (2.5s)
KID > 0.5=K <0.5 = p; Belle Std (Fang Fang) KS
R2<0.4; |cosqB| < 0.9
|Mbc – 5.28|< GeV (2.5s)
|DE|<0.031 GeV (2.5s)

5. Constrain tracks to MB sM(py’) = 2.5 MeV for both modes
After the constraint:
sM (y’  l+l-)  4.4 MeV
2.5s
sM (J/y  l+l-)  5.3 MeV
Use:
M(py’) = M(pl+l-) – M(l+l-) + my’(PDG)’
y’  l+l- mode
y’  p+p- J/y
M(py’) = M(p ppJ/y) – M(ppJ/y) + my’(PDG)
sM(py’) = 2.5 MeV for both modes
M(py’) resolution is not an issue

6. Dalitz Plot, Selected events
What’s this??
M2(p+y’)
K2*(1430)K+p-
(dble-lobed D-wave?)
K*(890)K+p-
M2(K+p-)

7. Dalitz Plot, M(K+y’) vs M(K+p)

8. M(Kp) K*(890) = 1742  59 evts K2*(1430) = 103  36 evts
N(“phase-space”) = 1112 ± 63 evts
Cut out K*(890) & K*(1430)
± 100 MeV

9. M(p+ y’) (with K* veto) Strong narrow signal; very little bkgd
DE sideband bkg
(consistent with
Mbc & DE fitting
Mpeak±30MeV

10. Fit peak to an S-wave BW Belle Phase-space-like function for
PRL
Phase-space-like
function for
bkg+continuum

11. Compare data subsamples
Significant ~4433 MeV in all subsets

12. M(py’) & cosqp are very tightly correlated
Cos qp vs M2(py’) p qp y’ K
+1.0
22 GeV2
(4.43)2GeV2
0.25
M2(py’)
cosqp
16 GeV2
-1.0
M(py’) & cosqp are very tightly correlated

13. Interference between Kp partial waves?
Only S-, P- and D-waves seen in data
interfere
Add incoherently

14. 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.

15. Other “latest” XYZ results

16. 1-- states via ISR

17. Y(4260) & Y(4325) from BaBar p+p-J/y Not the same! p+p-y’ 233 fb-1
BaBar PRL95, (2005)
fitted values:
M=4259  8 +2 MeV
G = 88  MeV -6 -9
p+p-J/y
Not the same!
M=4324  24 MeV
G = 172  33 MeV
BaBar PRL (2007)
p+p-y’
S.W.Ye QWG-2006 June 2006

18. Belle results on the 1-- peaks
BaBar’s Y(4260)
p+p- J/y
Belle
Yuan et al
PRL99,182004
Y(4050)???
BaBar’s Y(4325)
Y(4360)
& Y(4660)
p+p- y’
Belle
Wang et al
PRL99,142002
K+K- J/y
Belle
Yuan et al

19. stot DD D*D* This means large partial widths for p+p- J/y (y’) DD*
These 1-- states
do not match well
to peaks in hadr.
cross-sections
Y(4360)
Y(4660)
Y(4008) DD
D*D*
This means large
partial widths for
p+p- J/y (y’)
(~few MeV or more)
DD*
Y(4260)
Pakhlova (Belle) PRL 98, (2007)

20. No unfilled charmonium assignments are available
Are these 1-- cc states？
4660
4360
No unfilled charmonium
assignments are available
(except, maybe, Y(4050))
4260
4050

21. Y(3940) confirmed by BaBar B±K±wJ/y B±K±wJ/y B0KSwJ/y ratio BaBar
B±K±wJ/y
B±K±wJ/y
B0KSwJ/y
M2(Kw)
ratio
M(wJ/y)
Some discrepancy in M & G; general features agree

22. Belle & BaBar data with the same binning
3915
data disagree
In this region
BaBar
Belle
rebin
PRL94, (2005)
(40 MeV bins)

23. M(D*D*)a new state at ~4160 MeV
Seen in e+e-J/yD*D*
(partial reconstruction)
D*-reconstructed + D*-tag
Paklov’s talk tomorrow
5.5 
M = ± 15 MeV
Gtot = ± 21MeV
Nsig = ± 11evts
-20
-61 -8
arXiv:
if 0++, why is it
not seen in DD
It has to have C=+; most likely 0-+,... possibly 0++

24. A cc assignment for X(4160) ? hc” hc’’’ Mass is too high or too low
(if y(3S)=y(4040))
or too low
(if y(3S) = y(4160))
hc”
4160
3940
Mass is far too low
(unless y(4S)=y(4160),
but, then, where is y(2D?))
3931
hc’’’
Can place either the
X(3940) or X(4160),
but probably not both.

25. Some 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
They are characterized by large partial widths (Bfs) to hadrons+J/y (or y’)
Br(X(3872)rJ/y) > 4.3% (Isospin=1)
G(Y(3940)wJ/y) > 7 MeV (SU(3) octet)
G(Y(4260)p+p-J/y) > 1.6 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’
Y(4260) not seen in Y(4260)ppy’
The new 1-- states are not apparent in the e+e-D(*)D(*) cross sections
There is no evident transitions at the D**D mass threshold
Some states are near thresholds, but not all of them

26. 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

27. Are there XYZ counterparts for the ss- & bb- systems?

28. 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

29. 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

30. 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)
If there are bb versions of the XYZ’s,
why not ss versions as well?

31. 1-- Ys states around 2 GeV? X.Y. Shen’s talk @ Ecm ~10.6 GeV
Y(2175)f0(980)f
from BaBar
(confirmed by BESII)
e+e-  g f0(980)h
@ Ecm ~10.6 GeV
confirmed by BESII
M(f0(980)f GeV
X.Y. Shen’s talk

32. Luciano had-2007

33. Now it looks like there may be XYZ-like
spectroscopies for the s- & b-quark sectors

34. 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)

35. 謝謝

36. Product Bf calculation
Only use K±
From PDG

37. Summary - 7.3s p+y’ inv mass peak in BKpy’ decays
- signif. signals seen in all
data sub-samples
- no produced by interference
effects in Kp system
JP=1+ slightly preferred
(over 0- & 1-)
- similar M & G to ppy’ peaks
found by X.Wang et al
- if it is a meson, it’s exotic

38. Backup slides

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

40. G for y’p+p-J/y vs G for y’l+l-
Nsignal = 53  15 evts
Mass = 4435  4 MeV
FWHM G = MeV
Signif = 4.5 s
y’l+l-
Nsignal = 105  35 evts
Mass = 4435  10 MeV
FWHM G = MeV
Signif = 4.7 s

41. Width comparison c2 = + = 4.8/1dof (94 – 45)2 (45-26)2 302 132
From the combined fit
(94 – 45) (45-26)2
c2 = = 4.8/1dof
~3% probability

42. Ratio of signal yields ppJ/y mode: 53 ± 15 from fit: = 0.5 ± 0.2
l+l- mode ± 35
from fit: = 0.5 ± 0.2
MC expt’n: 1.23
Yield & width are correlated.
Refit forcing both samples to have G=44MeV
ppJ/y mode: 64 ± 15
l+l- mode: ± 13
Constrained fit: = 1.1 ± 0.4 OK

43. M(Kp) in peak region K* veto relaxed

44. Systematic errors * Mass very small (~1 MeV) - y’ppJ/y - y’l+l-
- J/y l+l-
* Prod Bf
- correl with G 25%
- diff fitting fcns 7%
- diff JP values 6%
- PDG Bf’s 4%
- other ~2%
width very large +30/-11 MeV ??
- avg fluctuations in data subsamples
27%

45. XYZ states have large pp(w)J/y (y’) partial widths
G(Y(3940)  wJ/y) ~ 7 MeV
G(Y(4260) p+p-J/y) > 1.5 MeV
G(Z+(4430)p+y’) > 4 MeV …
As compared to charmonium:
G(y’p+p-J/y) ~ 100 keV
G(y’hJ/y) ~ 10 keV
G(y’’p+p-J/y) ~ 50 keV

46. Belle updates e+e-J/yD(*)D(*)
Use “partial reconstruction technique”
Continuum e+e-
annihilation
J/y e+ e-
reconstruct
these
D(*)
D(*)
“Recoil” D(*)
undetected
(inferred from
kinematics)