The oddball Y(4140) as the

cousin of Y(3930)

Xiang Liu & S. L. Zhu, Phys.Rev.D80, 017502 (2009) Xiang Liu, Z. G. Luo, Y. R. Liu and S. L. Zhu, Eur.Phys.J.C61:411-428 (2009) Xiang Liu, Phys.Lett. B680, 137-140 (2009)Xiang Liu & H.W. Ke, Phys.Rev.D80, 034009 (2009)

Xiang Liu xiangliu@lzu.edu.cn

School of Physical Science and TechnologyLanzhou University

QNP09 October 21-25 2009, at IHEP, China

See Phys.Rev.Lett.102:242002,2009

CDF experiment observed Y(4140)

+8.3-5.0

(4140)

4143.0 2.9 1.2 MeV

=11.7 3.7 MeV

Y

M

Y(4140) C parity: + G parity: +

Y

states:

(3872) X(3930)/ (3930)/Z(3930) Y(4260) Z (4430)

Charmonium like

X

Belle Collaboration BaBar CollaborationPhys.Rev.Lett.94:182002 (2005) Phys.Rev.Lett.101: 082001 (2008)

/B KJ

3.8 +123.4 -8

3943 11( ) 13( ) MeV =87 22(stat) 26(syst) MeV

3914.6 ( ) 2.0( ) MeV =34 ( ) 5( ) MeV

BELLE

M stat syst

BABAR

M stat syst stat syst

Both Y(4140) and Y(3930) were observed in the mass spectrum

of J/ +light vector meson

The similarities between Y

J/ (4140)

B

(414

K+

0) and Y(

3930)

Y

Y(4140) (

* *s s

3930)

The mass difference between Y(4140) and Y(3930) approximately equal to

that bet

J/ (3930)

Y(4140) and Y(3930) are close to

ween a

the thr

M

esholds

nd

of D D a

YM M

Y

M

* *

* *

Y(4140) (3930)

nd D D , and satisfy an

almost exact mass relation

M 2 2s

YD DM M M = - 90 MeV

* * * *s s(4140) is a molecular state whil D D De Y(3930) is its molecular pa rD rtneY

P

P

* *

Select rule

However for the neutr

The possible quantum num

al D D system with C=+

bers of the S-wave vector-vector system are

J 0 , since C=(-1) and J=S wit

, we ca

h

n have

J

L2

0 ,1 ,2 .

=0 L S

.

What is the structure for Y(4140)?

Wavefunction

Effective Potential

For details, see Xiang Liu, Z. G. Luo, Y. R. Liu, S.L. Zhu, Eur.Phys.J.C61:411-428,2009

The shape of the potential of Y(4140) and Y(3930)

Decay Patterns of Y (4140) and Y (3930)

This S-wave decay occurs via the rescattering mechanism

The discovery mode of Y(3930) and Y(4140)

Hidden charm decay is strongly suppressed

Hidden cha

for the co

rm two-body

nventional

dec

excite

y

d

a

This mode is not sppressed for heavy molecu

charmonium around 4 GeV.

Sometimes, they become o the

lar

dom

states.

inant decane y m oo f .des

Open charm two-body decays

D-wave

S-wave

Such a D-wave decay width should be much smaller than that for the above hidden charm S-wave decay mode!

The open-charm decay widths are comparable to the hidden-charm decay width

*s

*s

*

s s

Open charm three-body and four-body decays

Y(4140) : D , DKDK

Y(3930): , D

D , D D

(

D

v

is

DK

D isosp

D D

in

*

*s s s s s s

Kinematically Forbidden !!!

Y(3930): D D , D

D , D

D

olating modes)

Y(4140): D

Radiativ

e d

D , D D ,

ec

T

D D

y

a

h

and

e

spectrum are very interesting

Semi-leptonic and Non-leptonic decay

ra

diative

The s

the line shap

emi-leptonic an

decay widt

d non-lepto

e of

nic decays via on

the photonh

e component

of the molecular state also contain useful information of its

inner structure.

Xiang Liu & H.W. KePhys.Rev.D80, 034009 (2009)

Summary

We proposed a uniform molecular state assignment for Y(4140) and Y(3930)

* * * *s s(4140) is a molecular state whil D D De Y(3930) is its molecular pa rD rtneY

P

Find

a selec

t rule for the q

uantum nubmer of Y(4140) and Y(3

930) in the molec

ular picture

J 0 ,2

Their hidden-charm decay, open-charm decay, radiative decay are important and interesting to test molecular state assignment for Y(4140) and Y(3930).

Confirming Y(4140) in other experiments is important. Belle and Babar experiments.

We suggest the measurment of the line shape of the photon spectrum of the radiative decay of Y(4140) and Y(3930).

Thank you for your attention !

Backup slides

Charmonium

• Y (4140) lies well above the open charm decay threshold.

• Charmoniums with this mass would decay into an open charm pair dominantly.

• The branching fraction of its hidden charm decay mode is expected to be tiny.

Thus, both the narrow width of Y (4140) and its large hidden charm decay pattern disfavor the conventional charmonium interpretation.

/J 4 3 (see Xiang Liu, arXiv:0904.01310 1 6 [0 hep- h p ])BR

Tetraquark state• Tetraquarks will fall apart into a pair of charmed mesons very easily. • As a tetraquark, the width of Y (4140) would be around several hundred MeV instead of 12 MeV as observed by CDF.

[see Y. Cui, X. L. Chen, W. Z. Deng, S.L. Zhu, HEP&NP 31, 7 (2007)

P

]

+ +

P +

J = 0 , 1 M=

The simple chromo-magneti

4.1 GeV

J =

c

2

interaction:

u

nbound

ccss

The B meson decay process does not provide a glue-rich environment as in the Upsilon/charmonium annihilation.

So the possibility of Y (4140) being a hybrid state is small.

P

A partner of Y(4260) within the same

J 1 hybrid charmonium family Hybrid state

- -

(1) the narrow width of Y(4140) < the width of Y(4260)

(2) the different decay patterns of Y(4140) and Y(4260)

J/ J J/

(3) the simila

/

rity

K K

between Y(4140) and Y(3930)