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

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

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

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

Charmonium after B-factories

Some examples

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

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

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 = 0+  × B(X(3915)ωJ/ψ) = (69 ± 16+7–18) eV ωJ/ψ partial width ~ 1 MeV is quite large for conventional charmonium

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

ΛC(2940)+

X(3250) PRD 86 091102 (2012) Taken from Gruenberger Proc Rencontres de Moriond QCD 2012)

Non conventional charmonium Picture from Piilone Charm 2012

Molecular hypothesis

The Constituent Quark Model

The constituent quark model

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. C62 034002 (2000) B. Juliá-Diaz, J. Haidenbauer, A. Valcarce, and F. Fernández. Physical Review C 65, 034001, (2002) Baryon spectrum H. Garcilazo, A. Valcarce, F. Fernández. Phys. Rev. C 64, 058201, (2001) H. Garcilazo, A. Valcarce, F. Fernández. Phys. Rev. C 63, 035207 (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. 78 114033 (2008) .Reports A. Valcarce, H. Garcilazo, F. Fernandez, P.Gonzalez Rep. Prog. Phys. 68 965 (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.

Results for the 1- - sector PRD 78 114033 (2008)

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

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

Coupling: Pair Creation Model

Coupled channels:

Coupled channels:

Coupled channels:

Hidden Charm Meson Sector

Results: JPC=1++ sector

Results: JPC=1++ sector J. Phys. G 40 085107 (2013)

Results: JPC=1++ sector Theory J. Phys. G 40 085107 (2013)

Results: JPC=0++ sector J. Phys. G 40 085107 (2013)

Results: JPC=1-- sector

Charmed Baryon Sector

The Baryon Meson system

The Baryon Meson system

D(*) N and D(*) Δ States

D(*)N and D(*)Δ Decays Widths

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

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-

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

Thanks for your attention End Thanks for your attention

Back slides

X(3872) gamma decay

Results for XYZ states: Z(3930) Observed by Belle Collab. produced in PRL 96 (06) 082003 Helicity angle distribution favours J=2 Our results M=3968 MeV. =49.1 MeV.

Results for XYZ states: X(4160) e+e−  J/ D*D* observed by Belle in M=(4156 15)MeV/c2  =(139 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)

Results for XYZ states