1. New Resonances from B-factories
J. Brodzicka (KEK) for Belle
KEKTH’07, Tsukuba

2. A lot of states, a lot of production processes…
J. Brodzicka for KEKTH’07
A lot of states, a lot of production processes…

3. B-Factories are Charmonium factories
J. Brodzicka for KEKTH’07
B-Factories are Charmonium factories
cc (-like) production B-Factory
B meson decays i.e. B→Xcc K(*)
e+e- radiative return (ISR)
e+e-→γISRXcc →γISR J/ψππ
e+e- annihilation i.e. double cc
production e+e-→J/ψXcc
γγ collision e+e-→γγ→Xcc→DD
B X W
K(*)
b c
u, d c s
u, d
e J/ψ X e- c
γ * c
e e+
e e- X D γ e+ e- π
J/ψ
γISR γ* X

4. A lot of data from KEK-B Factory…
J. Brodzicka for KEKTH’07
A lot of data from KEK-B Factory…
Asymmetric e+e- collider Tsukuba
e+: 3.5 GeV  e-: 8.0 GeV
CM energy: GeV at (4S)
e+e-  (4S)  BB
Advantages:
exclusive source of BB pairs
useful kinematical constraints
high signal-to-background ratio
separation of B decay vertices
Record luminosity peak: 1.711034cm-2s-1
Integrated luminosity: ~750 fb-1
~ 780 * 106 BB
~ 960 * 106 cc
Beauty and Charm Factory

5. …recorded with the Belle detector
J. Brodzicka for KEKTH’07
…recorded with the Belle detector
Silicon Vertex Detector
KL / Detector
SC Solenoid
1.5T
Central Drift Chamber
Aerogel Cherenkov Counter
Electromagnetic Calorimeter
Time of Flight Counter
Event reconstruction
Charged tracks
Central Drift Chamber
Silicon Vertex Detector
Electrons and photons
Electromagnetic Calorimeter
3.5 GeV e+
Particle identification
K/ separation
Central Drift Chamber: dE/dx
Aerogel Cherenkov Counter
Time of Flight Counter
Electron identification
Electromagnetic Calorimeter
KL and  identification
KL and muon detector
Vertexing
Silicon Vertex Detector
8 GeV e-

6. B decays as a charmonium-like factory
J. Brodzicka for KEKTH’07
B decays as a charmonium-like factory
B→Xcc K(*) decays used:
b→cW→ccs is dominant process (exclusive BF ~10-3)
background reduction is possible
JP of parent B is known → JP of the child particles can be
determined from angular analysis
J=0, 1 states should dominate (if factorization assumed)
b c
u, d c s
K(*)
u, d
B charmonium (-like)
W η, χc, J/ψ, ψ’…
Good place for
spectroscopy study!
Cabbibo-favored
vertices

7. How to identify B meson signal
J. Brodzicka for KEKTH’07
How to identify B meson signal
We take advantage of e+e-→(4S) → BB kinematics
m(4S)~ mB + mB no accompanying particles
→ EB=Ebeam=√s/2 in  cms
kinematical variables used in B-Factories
Mbc= √E2beam- p2B
beam-constrained mass
(signal at mB~5.28GeV)
ΔE=EB - Ebeam
cms energy difference
(signal peaks at 0)
Resolution improvement
(Ebeam is precisely known)
Background separation
Mbc ΔE
Example:
B0→ J/ψ KS

8. Reminder on X(3872) X(3872)→J/ψπ+π- observed in B+→X(3872)K+ by Belle
J. Brodzicka for KEKTH’07
Reminder on X(3872)
X(3872)→J/ψπ+π- observed in B+→X(3872)K+ by Belle
confirmed by BaBar, CDF, D0
PRL91, (2003)
X(3872)→J/ψππ
Ψ(2S)→J/ψππ
M(J/ψπ+π-)
152M BB
BF(B→KX)*BF(X→J/ψππ)
= (1.3±0.2±0.1)*10-5
117M BB

9. Properties of X(3872) mX=3871.2 ± 0.5MeV ≈ mD*0+mD0 (PDG06)
J. Brodzicka for KEKTH’07
Properties of X(3872)
mX= ± 0.5MeV ≈ mD*0+mD0 (PDG06)
narrow: Γ<2.3MeV
above DD threshold but no X→DD found PRL93, (2004)
M(π+π-) is like ρ(770), so X(3872)→J/ψρ?
Other decay modes: J/ψγ, J/ψω
Favored JPC= 1++
(angular analysis by Belle/CDF, decay modes)
What is X(3872)?
cc? Does not match any cc predicted by quark models
DD* molecule? mX-(mD*0+mD0)= -0.6±0.6 MeV above/below DD*?
4-quark? Would explain small width. Charged X should exist
M(π+π-)

10. J. Brodzicka for Belle @ KEKTH’07
Is X(3872) a cc state ?

11. J. Brodzicka for Belle @ KEKTH’07
X(3872) in B+ and B0 decays
BELLE-CONF-0711
Study of X(3872)→J/ψπ+π- in B+→XK+ and B0→XK0s (657M BB)
control sample: B→ψ’K ψ’→J/ψππ to calibrate mass & resolution
after Mbc and ΔE selection:
similar properties of X(3872) from B+ and B0 decays
(this disfavors some theoretical models)
B+→XK+
Ns=125±14
(12σ)
657M BB
M(J/ψπ+π-)
B0→XK0s
Ns=30±7
(6.5σ)
First observation!
M(J/ψπ+π-)

12. X(3872)→DD* X(3872) is very close to D*0D0 threshold
J. Brodzicka for KEKTH’07
X(3872)→DD*
X(3872) is very close to D*0D0 threshold
BaBar: B+→D*0D0K D*0 →D0π0,D0γ (383M BB)
Belle: B+→D0D0 π0K (447M BB)
mass ~4σ above M(X) for X→J/ψππ
are there two states X(3872) and X(3875)?
N=33±7 (4.9σ)
N=24±6 (6.4σ)
hep-ex/
PRL97, (2006)
M(X)= ±0.5 MeV
Γ= ± 0.9 MeV
M(X)= ± ±0.9 MeV

13. What is X(3872)? Xu= Xd= u c d c 4-quark model:
J. Brodzicka for KEKTH’07
What is X(3872)?
4-quark model:
Xu [uc][uc] state decaying to D0D0π0 = X(3875)
Xd [dc][dc] state decaying to J/Ψπ+π- = X(3872)
Finding charged partner is critical
Molecule model:
X is D*0D0 bound state (mX ≈ mD*0+ mD0)
Favors DDπ over J/ψππ
Line shape depends on the decay channel
X(3872) properties still under investigation
(mass, width, line shape, decay modes…)
Maiani, Polosa et al.
hep-ph/ u c
Xu= d c
Xd=
Braaten et al.
hep-ph/

14. J. Brodzicka for Belle @ KEKTH’07
Recently…

15. Observation of Z+(4430)→ψ’π+
J. Brodzicka for KEKTH’07
Observation of Z+(4430)→ψ’π+
hep-ex/
Submitted to PRL
Belle studied B0 →ψ’π+K- and B+→ψ’π+K0s (657M BB)
ψ’→ e+e-, μ+μ- or J/ψπ+π- J/ψ →e+e-, μ+μ-
secondary particles combined to B→ψ’π+K candidates
Mbc and ΔE selection: clear B→ψ’π+K signal

16. Observation of Z+(4430)→ψ’π+
J. Brodzicka for KEKTH’07
Observation of Z+(4430)→ψ’π+
in B→ψ’π+K Dalitz plot:
K*→π+K states and a clear band at M2(ψ’π+)~20GeV2
K*veto applied to study of ψ’π+ (both K* regions excluded)
M(ψ’π+) fit: Breit-Wigner + ph.space like function
prominent peak
(K* veto applied)
3-body decays
non-B
background
M2(ψ’π+)
M2(Kπ+)
K*(890)
K2*(1430)
???
Z+(4430)
N =121±30
(6.5σ)
M(ψ’π+)
M= 4433 ± 4 MeV Γ= MeV

17. Z+(4430) →ψ’π+ Z(4430) signal is robust: M= 4433 ± 4 ± 2 MeV Γ= 45 MeV
J. Brodzicka for KEKTH’07
Z+(4430) →ψ’π+
Z(4430) signal is robust:
B generic MC studied → Z(4430) is not a reflection
data subsets checked, K* veto changed
interference between Kπ partial waves (S,P,D)
→ cannot produce such narrow peak in ψ’π+
M= 4433 ± 4 ± 2 MeV Γ= MeV –
Z+(4430)
BF(B→KZ)*BF(Z→ψ’π+) = (4.1 ±1.0±1.4 )*10-5
JP not determined, statistics too low
First candidate for a charged cc-like state!
Must be exotic!
Z(4430) could be a tetraquark state [cu][cd]
(Charged states naturally appear in 4-quark models)
Radial excitation of X(3872/5) family?
Maiani, Polosa et al.
hep-hp/

18. Y(3940)→J/ψω from Belle Study of B→ KJ/ψω (275M BB)
J. Brodzicka for KEKTH’07
Y(3940)→J/ψω from Belle
PRL 94, (2005)
Study of B→ KJ/ψω (275M BB)
J/ψ→ee, μμ ω→π+π-π0
Mbc , ΔE and M(π+π-π0) selection
M(ωK)>1.6GeV: K* veto
Y is above DD threshold but has large cc transition
Candidate for cc-gluon hybrid?
(but hybrids predicted above 4GeV)
M2(ωK)
M2(ωJ/ψ)
K*’s
Y(3940)
M(ωJ/ψ)
N=58±11
M= 3943±11±13 MeV
Г=87±22±26 MeV
BF(B→KY)*BF(Y→J/ψω)
=(7.1±1.3±3.1)*10-5

19. Y(3940) confirmed by BaBar Similar study of B→ KJ/ψω (383M BB)
J. Brodzicka for KEKTH’07
Y(3940) confirmed by BaBar
hep-ex/
submitted to PRL
Similar study of B→ KJ/ψω (383M BB)
But events weighted according to helicity
distribution expected for ω→π+π-π0 (~sin2θ)
(projects the signal, reduces background)
Fit to acceptance corrected M(J/ψω)
M= 3914 ±4 ±2 MeV Г= ±5 MeV mass and width smaller
than Y(3940) from Belle
BF(B+→K+Y)*BF(Y→J/ψω)=(4.9±1.0±0.5)*10-5
BF(B0→K0Y)*BF(Y→J/ψω)<3.9*10-5
M(π+π-π0)
Mbc
M(J/ψω)
B+→K+ J/ψω
B0→K0 J/ψω ΔE
+12
– 8

20. Double cc production: e+e-→J/ψ(cc)res
J. Brodzicka for KEKTH’07
Double cc production: e+e-→J/ψ(cc)res
PRL 98, (2007)
e J/ψ X e- c
γ * c
Factory of 0++ and 0-+ charmonia
Method: reconstruct J/ψ, study recoil mass
Mrecoil(J/ψ) =√(Ecm-E J/ψ)2 -p2 J/ψ
Surprises:
below DD: cc states with large x-sections O(10-20fb)
above DD: new state X(3940)
Method is limited: σ~30MeV; remainder system not reconstructed → its identification indirect
N=266±63 (5σ)
M=3936±14 MeV
Γ=39±26 MeV
one state or more?
357fb-1
so X(3940) it’s not Y(3940)

21. Double cc production: e+e-→J/ψ D(*)D(*)
J. Brodzicka for KEKTH’07
Double cc production: e+e-→J/ψ D(*)D(*)
D(*)D(*) resonances through e+e- →J/ψ D(*)D(*)
Reconstruct J/ψ and one D(*) , study Mrecoil(J/ψD(*) )
Associated D(*) seen as peak in Mrecoil(J/ψD(*))
Tagged processes: J/ψDD , J/ψDD* , J/ψD*D* (all >5σ)
Mrec(J/ψD)
D D* D*π
693fb-1
Mrec(J/ψD*)
D D*
hep-ex/
submitted to PRL

22. Double cc production: e+e-→J/ψ D(*)D(*)
J. Brodzicka for KEKTH’07
Double cc production: e+e-→J/ψ D(*)D(*)
Constrain Mrecoil(J/ψD(*)) from the peak regions
to the nominal mass of associated D(*)
Tagged & constrained: e+e-→J/ψ D(*)D(*)
so Mrecoil(J/ψ) = M(D(*)D(*))
ee→J/ψ DD
Mrec(J/ψD)
M(DD)
D D* D*π
M(DD) is not non-resonant
one broad resonance or more?
fit unstable, significance low
remains inconclusive

23. X(3940) and X(4160) X(3940)→DD* visible in inclusive Mrecoil(J/ψD)
J. Brodzicka for KEKTH’07
X(3940) and X(4160)
X(3940)→DD* visible in inclusive Mrecoil(J/ψD)
X(4160) →D*D* one more particle (C=+1 so it’s not ψ(4160))
Possible assignments: ηc(3S) ηc(4S)
Mrec(J/ψD)
D D* D*π
D D*
Mrec(J/ψD*)
ee→J/ψ D*D*
X(4160) 5.5σ
M(D*D*)
ee→J/ψ DD*
X(3940) 6.0σ
M(D*D)
N = 24
M = ± 15 MeV
 = ± 21 MeV
+25
–20
+111
– 61
+12
– 8
N = 52
M = ± 6 MeV
 = ± 12 MeV +7 –6
+26
–15
+24
–16

24. Y family from ISR studies
J. Brodzicka for KEKTH’07
Y family from ISR studies
PRL 95, (2005)
for 232fb-1
CLEO PRD74, (2006)
CLEO-c PRL 96, (2006)
for
Y(4260)→J/ψππ
Y(4350)→ψ’ππ
M = 4259 ± MeV
 = 88 ± MeV
(Y→ee)*B(Y→J/ψππ)=5.5± eV +2 –6 +6 –4
+0.8
–0.7
PRL 98, (2007)
for 298fb-1

25. Y→J/ψππ via ISR γISR ISR gives access to JPC=1-- states
J. Brodzicka for KEKTH’07
Y→J/ψππ via ISR
PRL 99, (2007) e+ e- π
J/ψ
γISR γ* X
ISR gives access to JPC=1-- states
Study of e+e-→J/ψπ+π- γISR (548 fb-1)
Selection: J/ψ→ee, μμ + ππ; no extra tracks
ISR photon is not detected
Missing mass used to identify process
In M(J/ψππ): ψ’ signal and two clusters
of events Ψ’
Y(4260)

26. Y→J/ψππ via ISR Fit to M(J/ψππ) with two interfering Breit-Wigners
J. Brodzicka for KEKTH’07
Y→J/ψππ via ISR
PRL 99, (2007)
Fit to M(J/ψππ) with two interfering Breit-Wigners
Two solutions (destructive/constructive interference)
Y(4260) confirmed
Y(4008) broad state? Re-scattering from DD*?
Coupled-channel effect? Non-resonant component?
Y(4260)
Y(4008)

27. J/ψππ from ISR studies Using ISR we can measure hadronic x-sections
J. Brodzicka for KEKTH’07
J/ψππ from ISR studies
Using ISR we can measure hadronic x-sections
in wide energy range
Model independent measurement
M(J/ψππ): background subtracted, corrected for efficiency and luminosity → Cross-section for e+e-→J/ψπ+π-

28. Y→ψ’ππ via ISR Belle studied e+e-→ψ’π+π- γISR (673 fb-1)
J. Brodzicka for KEKTH’07
Y→ψ’ππ via ISR
PRL 99, (2007)
Belle studied e+e-→ψ’π+π- γISR (673 fb-1)
ψ’→J/ψππ, J/ψ→ee, μμ + ππ; no extra tracks
γISR not detected
Very low background
Two significant peaks observed in M(ψ’ππ)
One close to Babar’s Y(4360) but more narrow
Y(4360) new

29. Y→ψ’ππ via ISR M(ψ’ππ) fitted with two coherent Breit-Wigner functions
J. Brodzicka for KEKTH’07
Y→ψ’ππ via ISR
PRL 99, (2007)
M(ψ’ππ) fitted with two coherent Breit-Wigner functions
Two solutions (for destructive/constructive interference)
Y(4360)
Y(4660)

30. e+e-→J/ψKK via ISR Belle studies e+e-→J/ψKK γISR (673fb-1)
J. Brodzicka for KEKTH’07
e+e-→J/ψKK via ISR
hep-ex/
to appear in PRD
Belle studies e+e-→J/ψKK γISR (673fb-1)
First observation of e+e-→J/ψK+K- γISR
and evidence for e+e-→J/ψKsKs γISR
M(J/ψKK) inconclusive

31. 1 - - Y states via ISR p+p- J/y p+p- y’ l K+K- J/y Y(4260) Y(4660)
J. Brodzicka for KEKTH’07
1 - - Y states via ISR
p+p- J/y l
Y(4260)
Y(4008)
Y(4660)
Y(4360)
p+p- y’
K+K- J/y

32. Do Y states decay to D(*)D(*) ?
J. Brodzicka for KEKTH’07
Do Y states decay to D(*)D(*) ?
All Y states above DD, should decay to D(*)D(*)
Y states do not match well to peaks in hadronic x-sections
This means large partial widths to ψππ (unlike for ordinary cc)
ψ(4040) ψ(4160) ψ(4415)
σ(nb)
D*D*
D*D DD
Y(4260)
Y(4360)
Y(4660)
PRL 98, (2007)
hep-ex/
to appear in PRD(RC)

33. Look for Yb : bb counterpart of Y(4260)
J. Brodzicka for KEKTH’07
Look for Yb : bb counterpart of Y(4260)
hep-ex/
If bb follows the pattern in cc , Yb should exist: Yb→Y(nS)ππ
Proposal: study of Y(5S) data
Belle collected 21.7 fb-1 at √s~10.87GeV
Only one energy point. At Y(5S) or nearby?
Let’s call it “Y(5S)”
“Y(5S)”→Y(nS)π+π- Y(nS)→μ+μ-
ΔM= M(Y(mS))-M(Y(nS))=M(μμππ)-M(μμ) m>n
Hou, PRD74, (2006)
“Y(5S)”→Y(2S)ππ
“Y(5S)”→Y(1S)ππ
Y(1S)
Y(2S)
Y(3S)
“Y(5S)”→Y(3S)ππ
“Y(5S)”→Y(2S)ππ
“Y(5S)”→Y(1S)ππ

34. Huge Y(5S)→Y(nS)ππ Do we see Yb?
J. Brodzicka for KEKTH’07
Huge Y(5S)→Y(nS)ππ Do we see Yb?
Process Yield σ(pb) BF(%) Г(MeV)
“Y(5S)”→Y(1S)ππ ± ±0.1± ±0.03± ±0.04±0.09
“Y(5S)”→Y(2S)ππ ± ±0.2± ±0.06± ±0.07±0.16
“Y(5S)”→Y(3S)ππ ± ±0.5± ±0.18± ±0.20±0.10
assuming σ=0.302±0.015nb Large!
Large Y(5S)→Y(nS)ππ partial widths! For other bb: O(keV)
Do not agree with hypothesis for pure bb state
Is it Yb? Mixture of Y(5S) and Yb?
Energy scan around Y(5S) needed

35. Ys: strange version of Y(4260)?
J. Brodzicka for KEKTH’07
Ys: strange version of Y(4260)?
Y(2175)→ f0(980) φ from BaBar
(confirmed by BESII)
confirmed by BESII
PRD74, (R) (2006)

36. Z(3930) from γγ γ X Only C=+1 states produced
J. Brodzicka for KEKTH’07
Z(3930) from γγ
PRL 96, (2006)
e e+
e e- X D γ
Only C=+1 states produced
ee→γγ→DD studied (395fb-1)
Peak observed M(DD)~3.93GeV
N=64±18 M=3929±5±2MeV Г=29±10±2MeV
Гγγ*BF(Z→DD)=0.18± 0.05±0.03 keV (for J=2)
Spin-2 favored over spin-0 by helicity distribution
Z(3930) is χ’c2 candidiate
Z(3930)
J=2
J=0

37. J. Brodzicka for Belle @ KEKTH’07
A lot of XYZ states… ll

38. cc (-like) state of art We added a few new states…
J. Brodzicka for KEKTH’07
cc (-like) state of art
We added a few new states…
Are they cc? Do we understand them?
ηc(4S)
Y(3360), Y(3660)

39. Summary Do we see new charmonium spectroscopy @4GeV?
J. Brodzicka for KEKTH’07
Summary
Do we see new charmonium
There are good candidates for hybrids, multiquarks
Y(3940) X(3872) Z(4430) Y-family…
XYZ spectroscopy in s and b quark sectors? Yb, Ys?

40. Lots of pieces… Are they all from the same puzzle? Y(3940) Z(4430)
J. Brodzicka for KEKTH’07
Lots of pieces…
Y(3940)
Z(4430)
X(4160)
Are they all from the same puzzle?
Y(4660)
Y(4008)
Y(4260)
Y(4360)
X(3872)

41. J. Brodzicka for Belle @ KEKTH’07
Backup

42. Yb counterpart ? M(ππ) and cosθhel studied
J. Brodzicka for KEKTH’07
Yb counterpart ?
M(ππ) and cosθhel studied
Brown-Cahn (CLEO) model (grey)
generic phase space (open)

43. Double cc production: e+e-→J/ψ(cc)res
J. Brodzicka for KEKTH’07
Double cc production: e+e-→J/ψ(cc)res . D D* 
J/ψ e+ e-

44. J. Brodzicka for Belle @ KEKTH’07
Y(3940) hybrid? B