Charmonium states in the string breaking region

CHARMONIUM STATES IN THE STRING BREAKING REGION

Francisco FernándezNuclear Physics Group and IUFFyM

University of Salamanca

XIII International Conference on Hadron Spectroscopy

November 29 - December 4, 2009Florida 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

( ) (1 )rcV r a e

r

Lattice

(K.D. Born PRD40 1653)

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

XYZX(3840)

X(3915)

X(3940)

Y(3940)

X(4160)

Y(4208)

Y(4260)

Y(4360)

Y(4660)

.

.

Charmonium

e+e–→Λc+Λc

– γISR

Phys.Rev.Lett.101,172001(2008)

Charmonium states in the string breaking region

Van Beveren & Rupp

Basic ingredientsChiral symmetry is spontaneously broken at some momentum scale provinding a constituent quark mass M(q2) 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

02 2

020

lns

qq reduced mass

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. 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 PRD 78 114033

The constituent quark model

0

2 0 0

4 0 0

6 0 0

8 0 0

1 0 0 0

1 2 0 0

1 4 0 0

1 6 0 0

1 8 0 0

2 0 0 0

E (

MeV

)

0 -+ 2 -+ (1 --) 3 -- b 1(1 + -) a 2(2 + +) a 1(1 + +)

Light I=1

The constituent quark model

9 2 0 0

9 4 0 0

9 6 0 0

9 8 0 0

1 0 0 0 0

1 0 2 0 0

1 0 4 0 0

1 0 6 0 0

1 0 8 0 0

11 0 0 0

11 2 0 0E

(M

eV)

b(0 -+ ) (1 --) b 0(0 + + ) b 1(1 + +) b 2(2 + + ) (2 --)

Bottomonium

The constituent quark model

The constituent quark model

The 1-- sector

The 1-- sector

The 1-- sector

► Y(4008 ) and Y(4260) are not 1- - states

► Y(4360 ) and Y(4660) appears as 1- - states

► Ψ(4415) → 3D state

Leptonic width

The 1-- sector

Strong widths (3P0 model)

The 1-- sector

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

e e J / (cc)

X(3872)

DD* molecule coupled to

X(3940)

cc

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

See Entem’s talk

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

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

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

e+e− J/ D*D*

M=(4156 15)MeV/c2

=(139 21)MeV

+25−20

+111 −61

5.5 X(4160)

D*reconstructed D*tag

X(4160)

M=4166 MeV/c2

=122.9 MeV

Our results

((D*D*) =52.3 MeV)

2 (2 )c

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

Z(3930)

PRL 96 (06) 082003

• Observed in 2005 by Belle Collab.• produced in

Helicity angle distribution favours J=2

( (3930)) .18 0.05 0 ..03B Z DD keV

3929 5 2 .

29.9 10 2 .

M MeV

MeV

DD

Our results 2 (2 )c

M=3968 MeV. =49.1 MeV.

( (3930)) 0.15 .B Z DD keV

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