Charmonium states in the string breaking region CHARMONIUM STATES IN THE STRING BREAKING REGION Francisco Fernández Nuclear Physics Group and IUFFyM University of Salamanca XIII International Conference on Hadron Spectroscopy November 29 - December 4, 2009 Florida State University

MOTIVATIONS The breaking of the color electric string between two static sources is a phenomenon predicted by QCD String breaking has been observed in lattice QCD simulation Interesting issues Information about quark confinement Chiral symmetry restoration To study the properties of the very high excited states in charmonium in a model which reproduces the phenomenology Charmonium states in the string breaking region Aim

Charmonium states in the string breaking region

Confinement A poor´s man model Lattice (K.D. Born PRD ) ‏ Other choices are posible (see last talk of the sesion ) ‏

Are there enough experimental data in this region?

Excited states in the light sector Cristal Barrel Collaboration

XYZ X(3840) ‏ X(3915) ‏ X(3940) ‏ Y(3940) ‏ X(4160) ‏ Y(4208) ‏ Y(4260) ‏ Y(4360) ‏ Y(4660) ‏. Charmonium

e + e – → Λ c + Λ c – γ ISR Phys.Rev.Lett.101,172001(2008)‏ Charmonium states in the string breaking region Van Beveren & Rupp

Basic ingredients Chiral symmetry is spontaneously broken at some momentum scale provinding a constituent quark mass M(q 2 ) for the ligth quarks The constituent quark model

As a consequence light constituent quarks exchange Goldstone bosons Both light and heavy quarks interacts besides by gluon exchange Finally both type of quarks are confined by a two body linear potential screened at large distancies due to pair creation The constituent quark model

The quark gluon coupling constant scales with the reduced mass as J. Vijande, F. Fernández, A. Valcarce. J. Phys. G31, (2005) ‏ We can use the same parametrization for the light and heavy sector 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 PRD The constituent quark model

Light I=1 The constituent quark model

Bottomonium The constituent quark model

The 1 -- sector

► Y(4008 ) and Y(4260) are not states ► Y(4360 ) and Y(4660) appears as states ► Ψ(4415) → 3D state

Leptonic width The 1 -- sector

Strong widths ( 3 P 0 model) ‏ The 1 -- sector

X(3872) X(3915) X(3940) Z(3930) X(4160)‏

X(3872) ‏ DD* molecule coupled to X(3940) ‏ X(3872) X(3915) X(3940) Z(3930) X(4160)‏ See Entem’s talk

X(3872) X(3915) X(3940) Z(3930) X(4160)‏

e + e −  J/  D * D * M=(4156  15)MeV/c 2  =(139  21)MeV +25 − −  X(4160)‏ D * reconstructed D * tag X(4160) ‏ M=4166 MeV/c 2  =122.9 MeV Our results (  (D*D*) =52.3 MeV) ‏

X(3872) X(3915) X(3940) Z(3930) X(4160)‏

Z(3930) ‏ PRL 96 (06) Observed in 2005 by Belle Collab. produced in Helicity angle distribution favours J=2 Our results M=3968 MeV.  =49.1 MeV.

Van Beveren & Rupp analysis Charmonium states in the string breaking region

Charmonium states in the string breaking region Leptonic decays Strong decays

S-wave D-wave Charmonium states in the string breaking region

Charmonium states in the string breaking region

END THANKS