1. Heavy quark exotica and heavy quark symmetry
EIC
Heavy quark exotica and heavy quark symmetry
Yan-Rui Liu
(刘言锐)
Shandong University, China
Jul. 29, 2013

2. Content Heavy quark mesons Heavy quark symmetry Predictions
EIC
Content
Heavy quark mesons
Heavy quark symmetry
Predictions
Summary and perspective

3. Quark model and hadrons
EIC
Quark model and hadrons
Heavy quark
hadrons

4. Lightest

5. EIC
Heavy quark hadrons

6. Heavy quark spectra from
EIC
Heavy quark spectra from
Belle, Babar, CDF, SELEX, LHCb, BESIII, ...
Future: Higgs-factory, Z-factory, STCF, EIC?

7. EIC
Exotic like mesons
PDG12

8. EIC
Above DD threshold
Near threshold, coupled channel effects
Difficult to understand in QM

9. Exotic -like mesons Easier to produce than , ... A deuteron-like
EIC
Exotic like mesons
Easier to produce than , ...
A deuteron-like
molecule?

10. Exotic -like mesons BESIII:  + X(3872)  + charged states
EIC
Exotic like mesons
BESIII:
 + X(3872)
 + charged states

11. Charged exotic mesons Zb(10610), Zb(10650):
EIC
Charged exotic mesons
Zb(10610), Zb(10650):
PRL 108, (2012) [Belle]

12. C.Z. Yuan’s

13. C.Z. Yuan’s

14. Exotic mesons: interpretations
EIC
Exotic mesons: interpretations
Molecule or tetraquark?
e.g. Y(4260) & Z(3900) 
Hybrids?
Cusp?
Threshold effect?
Coupled channel effects?
...

15. Y(4260) & Zc(3900) EIC workshop@Weihai Q. Wang, C. Hanhart,
Q. Zhao,
D.Y. Chen, X. Liu, T. Matsuki,

16. EIC

17. QCD and heavy quark symmetry
EIC
QCD and heavy quark symmetry
QCD: hadrons
u < d < s < c < b < t
mq0, chiral symmetry, K
mQ, heavy quark symmetry (HQS)
:Simple but important , need more studies

18. EIC
Heavy quark symmetry
For a heavy quark Q interacting with light degrees of freedom, such as light quarks and gluons
Strong interactions:
(1) flavor blind  HQ flavor symmetry (HQFS)
(2) heavy quark spin orientation blind
 HQ spin symmetry (HQSS)

19. EIC
Heavy quark symmetry
HQFS
HQSS

20. Heavy quark symmetry (Multiplet structure)
EIC
Heavy quark symmetry (Multiplet structure)
both conserved

21. Heavy quark symmetry (Multiplet structure)
EIC
Heavy quark symmetry (Multiplet structure)

22. Heavy quark symmetry (Multiplet structure)
EIC
Heavy quark symmetry (Multiplet structure)
Q-hadron ?

23. HQSS constraints For interactions: EFT HQSS 
EIC
HQSS constraints
For interactions: EFT
HQSS 
For molecule decays: spin selection rules
For molecule production in annihilation: total angular momentum of light degree of freedom should be 0
...
T.M. Yan et a l., prd46,1148 (1992)

24. HQS selection rules in meson-antimeson structure
EIC
HQS selection rules in meson-antimeson structure
M.B. Voloshin, PLB 604,69; Y.R. Liu,

25. EIC
HQS selection rules
Two selection rules for in S-wave meson-antimeson states in HQ limit:
(a)
(b) if (A,B) is a doublet
Same rules for S-wave baryon-antibaryon states with the exception for two singlet baryons where
Heavy quark limit: conserved in strong decays of hadron-antihadron states

26. HQS selection rules EIC workshop@Weihai
X(3872) Not observed Zc(3900) Not observed
If no, maybe a tetraquark

27. HQS selection rules If Y(3940) is a molecule, c channelJ=0 or 2.
EIC
HQS selection rules
If Y(3940) is a molecule, c channelJ=0 or 2.
A charged state in J/?  J=1
A charged state in J/?  c: J=0 or 2

28. HQS selection rules J=1: J=2: J=3: EIC workshop@Weihai
cf. Probability for spin(cc)=0 in DD1 is 1/8

29. HQS in molecule production
EIC
HQS in molecule production
X. Li, M.B. Voloshin,
Heavy quark spin symmetry 
Y(4260) as a molecule is not supported
How large is the HQSS violation in decay and production?

30. Predictions of new exotica
EIC
Predictions of new exotica
Tornqvist’s predictions in
Z. Phys. C 61, 525 (1994)
One-pion exchange
approach including
tensor force

31. Predictions of new exotica
EIC
Predictions of new exotica
More meson-antimeson molecules are possible:
H-H, H-S, ...

32. Predictions of new exotica
EIC
Predictions of new exotica
X3 rearrangement decays to
: J=1,2,3, P=-, C=
Z3, Z2, Z1; X3, X2, X1
For C=+ case, attraction strong for X3 state
HQSS
Around the threshold, the J/ channel may be used to identify X3 with

33. The similarity between Y(4360) and Y(4260)
D.Y. Chen, Xiang Liu, T. Matsuki, arXiv:
The similarity between Y(4360) and Y(4260)
Novel charged charmoniumlike structures in the hidden-charm dipion decays of Y(4360)
Xiang STCF: ISPE mechanism

34. More on heavy quark hadrons
EIC
More on heavy quark hadrons
Tcc: tetraquark with quark content (ccqq)
cc, cN, cc, ...
Hidden charm N*:
mass > 4200 MeV NOT excited nucleon: exotic property
[Wu, Molina, Oset, Zou, PRL 105, (2010)]
Anomalous line shape in
...

35. Summary and perspective
EIC
Summary and perspective
Lots of unexpected observations have been made
More interesting phenomena above DD threshold are expected
Heavy quark (spin) symmetry plays an important role in understanding heavy quark exotica and might lead to more findings
Need more information from experiments:
Higgs-factory, Z-factory, STCF and/or EIC?
Thank you!