1. Molecular Structures in Hidden Charm Meson and Charmed Baryon Spectrum
The 6th International Workshop on Charm Physics
Molecular Structures in Hidden Charm Meson and Charmed Baryon Spectrum
F. Fernandez D.R. Entem, P.G. Ortega
Nuclear Physics Group and IUFFyM
University of Salamanca

2. Outline Motivation The constituent quark model
The coupled channels formalism
The meson-meson sector
The baryon meson sector
Summary

3. Charmonium before B-factories
1980 – 2002 : no new charmonium states

4. B-factories Data taking : 2000 – 2010 e+e– → (4S) Ecms ~ 10.6 GeV
@ KEK
@ SLAC

5. Charmonium after B-factories

7. Some examples

8. X(3872)
Quantum numbers compatibles with JPC=1++ and JPC=2-+ (ruled out by the recent LHCb data )
Width: Γ< 2,3 MeV
Mass: → below D0D*0 mass threshold

9. The XYZ near 3940 MeV
JPC=1++
JPC=?
JPC=2++
Babar M=3914±4.1

10. X(3915) γγ X(3915)  ωJ/ψ e+ 7.7 σ γ e– J = 0, 2 only
M(ωJ/ψ)
fit with no BW term
BW + background
N = 55 ±14+2–14 events
γγ X(3915)  ωJ/ψ
M = 3914 ±3± 2 MeV/c2
Γ = 23 ± 10+2–8 MeV γ e– e+
J/ ω X
J = 0, 2 only
2σ difference with Z(3930) mass
good agreement with BaBar’s Y(3940) mass seen in ωJ/ψ
for JP =  × B(X(3915)ωJ/ψ) = (69 ± 16+7–18) eV
ωJ/ψ partial width ~ 1 MeV
is quite large for conventional charmonium

11. G(3900)
JPC=1- - c  e+ e–
1– –
s=E2cm-2EEcm D - D Γ

12. ΛC(2940)+

13. X(3250)
PRD (2012)
Taken from Gruenberger Proc Rencontres de Moriond QCD 2012)

14. Non conventional charmonium
Picture from Piilone Charm 2012

15. Molecular hypothesis

16. The Constituent Quark Model

17. The constituent quark model

18. The constituent quark model
N-N interaction
F. Fernández, A. Valcarce, U. Straub, A. Faessler. J. Phys. G19, 2013 (1993)
A. Valcarce, A. Faessler, F. Fernández. Physics Letters B345, 367 (1995)
D.R. Entem, F. Fernández, A. Valcarce. Phys. Rev. C (2000)
B. Juliá-Diaz, J. Haidenbauer, A. Valcarce, and F. Fernández. Physical Review C 65, , (2002)
Baryon spectrum
H. Garcilazo, A. Valcarce, F. Fernández. Phys. Rev. C 64, , (2001)
H. Garcilazo, A. Valcarce, F. Fernández. Phys. Rev. C 63, (2001)
Meson spectrum.
J. Vijande, F. Fernández, A. Valcarce. J. Phys. G31, (2005)
J. Segovia, A. M. Yasser, D. R. Entem, F. Fernandez Phys. Rev D (2008)
.Reports
A. Valcarce, H. Garcilazo, F. Fernandez, P.Gonzalez Rep. Prog. Phys (2005)
J. Segovia, D. R. Entem, F. Fernandez, Int. Jour. Mod. Phys. E (to be published)
Diapositiva 4.
SIMULTANEIDAD
This model has been able to describe the NN interaction (NN phase shifts and deuteron phenomenology), the triton binding energy, baryon spectroscopy and meson spectroscopy and decays.

19. Results for the 1- - sector
PRD (2008)

20. Other XYZ states No candidates for :
X(3872), X(3915) G(3900) Y(3940) Y(4260)

21. Two quark states can mix with two meson with the same quantum numbers
Beyond the constituent quark model
Do we need to go beyond the naive constituent quark model to describe charmonium spectroscopy?
One possibility: Molecular state:
loosely bound state of a pair of mesons.
The dominant binding mechanism
should be pion exchange
Two quark states can mix with two meson with the same quantum numbers

22. Coupling: Pair Creation Model

23. Coupled channels:

24. Coupled channels:

25. Coupled channels:

26. Hidden Charm Meson Sector

27. Results: JPC=1++ sector

28. Results: JPC=1++ sector
J. Phys. G (2013)

29. Results: JPC=1++ sector
Theory
J. Phys. G (2013)

30. Results: JPC=0++ sector
J. Phys. G (2013)

31. Results: JPC=1-- sector

32. Charmed Baryon Sector

33. The Baryon Meson system

34. The Baryon Meson system

35. D(*) N and D(*) Δ States

36. D(*)N and D(*)Δ Decays Widths

37. Some selected states JP isospin state M (MeV)/c2 Eb (MeV) (MeV) 3/2-
D*N
2940,06
-8.02
20.76
1/2- 2
D*Δ
3232,70
-6.47
110.89
5/2- 1
3226,05
-13.12
107.5

38. Some selected states Λc (2940)+ → D*N (I) JP = (0) 3/2-
Isospin
state
M (MeV)/c2
Eb (MeV)
(MeV)
3/2-
D*N
2940,06
-8.02
20.76
1/2- 2
D*Δ
3232,70
-6.47
110.89
5/2- 1
3226,05
-13.12
107.5
State
M (MeV)/c2
(MeV)
Λc (2940)+
X(3250)
Λc (2940)+ → D*N (I) JP = (0) 3/2-
X(3250) → D*Δ (I) JP = (1) 5/2- or (I) JP = (2) 3/2-

39. Summary
We have study the influence of molecular structures in heavy meson and baryon phenomenology
We have used a constituent quark model to study both the meson and the molecular sectors
The model describe the X(3872) and other XYZ states as D D* resonances coupled to two quark states
We have extended our calculation to the baryon- meson sector
Without change the parameters we found a ND* bound states with JP=3/2- which can be identify with the Λc(2940)+ state
The recently reported Xc(3250) can also be explained as a D*Δ molecule
As final conclusion molecular structures may play an important role in the description of the meson and baryon espectra

40. Thanks for your attention
End
Thanks for your attention

41. Back slides

42. X(3872) gamma decay

43. Results for XYZ states: Z(3930)
Observed by Belle Collab.
produced in
PRL 96 (06)
Helicity angle distribution favours J=2
Our results
M= MeV. =49.1 MeV.

44. Results for XYZ states: X(4160)
e+e−  J/ D*D*
observed by Belle in
M=( 15)MeV/c2
 =( 21)MeV
+25
−20
+111
−61
5.5 
X(4160)
D*reconstructed D*tag
M=4166 MeV/c2
=122.9 MeV
Our results
((D*D*) =52.3 MeV)

52. Results for XYZ states