新强子态唯象理论进展
刘 翔
兰州大学
物理科学与技术学院
中国物理学会高能物理分会第八届全国会员代表大会暨学术年会 4月17-20日
南昌
Outline
• Charmonium-like state
X(3872), [Z(4430),Z(4051),Z(4248)], [Y(3930),Y(4140)]
[X(3915), Z(3930),X(4350)]
• Charmed-strange state
DsJ(2710), DsJ(2860), DsJ(3040)
• Bottom-strange state
Bs1(5830), Bs2(5840)
• Y(2175)-Y(4260)-Y(10870)
• Summary
Charmonium-like state
X
X
PRL91, 262001 (2003)
X(3872) observation
PRD71, 071103 (2005)
PRD73, 011101 (2006)
10s
B factories
in B decays
X(3872) first seen
in B →K J/π+π–
PRL98, 132002 (2007)
CDF 790fb-1: X→J/
π+π– angular analysis
only JPC=1++
and JPC = 2–+
M(J/π+π–)
PRL93, 072001 (2004)
1
PRL93, 162002 (2004)
新强子态唯象理论进展
• MX close to D0D*0 threshold
(not clear below or above)
M = 3871.4±0.6 MeV
MX – MDD* = (–0.40.7) MeV/c2
• surprisingly narrow:
Γtot < 2.3 MeV at 90% CL
• M(ππ) tends to kinematic limit
ππ=? Isospin violation!
刘翔 @ 兰州大学
Explanations to X(3872)
conventional charmonium
 JPC=1++ corresponds to c1(23P1)
expected Γ(c1′J/)/ Γ(c1′J/ ) ~30
measured ratio < 0.2
~ 100MeV/c2 lighter than expected.
3872
D0D*0 molecular state: (the most popular option)
E.S.Swanson, F.E.Close and P.R. Page,
M.B.Voloshin...
─
Tetraquark (cq)(cq):
u c
Xu = c u
L.Maiani, A.D.Polosa, V.Riquer, F.Piccini; D.Ebert,
R.N.Faustov, V.O.Galkin
─ (cd)(cd)
─ (cd)(cu),
─ with a few MeV
3 states (cu)(cu),
mass splitting
d c
Xd =
Hybrid (ccg) F.E.Close and P.R. Page
Threshold cusp D.V.Bugg
2
c d
B
0
X(3872)–
M(J/π–π0)
PRD71,031501 (2005)
B-
X(3872)–
M(J/π–π0)
NO evidence of X–(3872) J/–0
excludes isovector hypothesis
新强子态唯象理论进展
刘翔 @ 兰州大学
X(3872)→J/ψπ+π–
PRD77, 111101 (2008)
B+→XK+
8.6σ
2.3σ
B0→XK0s
BELLE-CONF-0849
Experimental evidence against
the molecular assignment
B+→XK+
12.8s
PRL102,132001 (2009)
B0→XK0s
5.9s
Relatively large Br(X→(2S)γ) is
─
0
*0
inconsistent with a pure D D
molecular interpretation for
X(3872)
Swanson, PLB598, 197 (2004)
Br(B0→XK0) / Br(B+→XK+) =
0.41 ± 0.24 ± 0.05
0.82 ± 0.22 ± 0.05
Molecular state:
the theoretical prediction is less than 0.1
Br(B0→XK0) Br(J/–+) =
(6.65 ± 1.63 ± 1.00)x10–6
3
新强子态唯象理论进展
刘翔 @ 兰州大学
• Reexamine the X(3872) by potential model
• Disfavor the molecular explanation if only considering one pion
exchange
• If including vector meson exchange, there exist the possibility
of DD^* molecular state assignment for X(3872).
Dynamics calculation
Liu, Liu, Deng, Zhu, EPJC56, 63 (2008)
Liu, Luo, Liu, Zhu, EPJC61, 411 (2009)
• However it is dependent on the parameter space.
What is the structure of X(3872)?
X (3872) : a dominant cc component with some
admixture of D0 D*0  D0 D*0
Suzuki, PRD72, 114013
Meng, Chao, arXiv:hep-ph/0506222
Zhu, IJMP, E17, 283
Liu, Liu, Deng, Zhu, EPJC56, 63
Mixing mechanism =Coupled channel effect
D
cc
4
π
c
cc
D*
新强子态唯象理论进展
c
u
u
刘翔 @ 兰州大学
Z(4430)- Z(4051)- Z(4248)charged charmonium-like state
If this result is confirmed first observation of a genuine ccud “exotic” state,
since it is charged and carries hidden charm.
PRL100, 142001 (2008)
PRD78, 072004 (2008)
Z(4430)
Z(4051)
Z(4248)
B→Z-K
Z-→ψ(2S)π-
6.5σ
+1830
M=4433  4  2 MeV =45-13
13 MeV
arXiv:0810.1073 [hep-ex]
No significant Z(4430) signal
is observed
5
新强子态唯象理论进展
刘翔 @ 兰州大学
Explanations for Z(4430)
Liu, Liu, Deng, Zhu, PRD77, 034003 (2008)
PRD77, 094015 (2008)
Rosner
S-wave threshold effect of
D1(2420)-D*(2010)
Dynamics calculation:
(Meng, Chao), Ding
D1(2420)D*(2010) molecule
D1' (2430) with broad width
S-wave D1D* system
(Maiania, Polosa,
Riquerd) and
(Gershtein,
Likhoded, Pronko)
Tetraquark state
Cheuanga, Keung,
Yuan
Bottom analog of Z(4430)
assuming it is a tetraquark
bound state
Lee, Mihara,
Navarra, Nielsen
S  wave D1' D* system
QSR
D1(2420)D*(2010)
Bugg
Cusp effect
(Braatten, Lu)
Studying the Line shape of
Z(4430)
Li, Lv, Wang
Partners of Z(4430) and
Productions in B Decays
6
only J P  0
 B1' B* system
 B1B* system
Tevatron and LHCb
__
Z(4051) disfavor a D*D* molecular state?
Liu, Luo, Liu, Zhu, EPJC61, 411 (2009)
Liu, Zhang, PRC80, 015208 (2009)
Z(4248): disfavor D1 D or D0 D*
molecular state!
Qiao
Liu, Zhao, Close
J P  0 ,1 , 2
The photoproduction of
Z(4430)
Ding, PRD79, 014001 (2009)
新强子态唯象理论进展
刘翔 @ 兰州大学
Phys.Rev.Lett.94:182002 (2005)
The similarities between
Y(4140) and Y(3930):
Y(3930)
 Both Y(4140) and Y(3930)
were observed in the mass
spectrum of J/ +light vector
meson
Phys.Rev.Lett.102:242002,2009
M  3943  11(stat )  13( syst ) MeV
=87  22(stat)  26(syst) MeV
J/  Y (4140)
B  K+
J/  Y (3930)
 The mass difference between
Phys.Rev.Lett.101: 082001 (2008)
Y(4140)
Y(3930)
Y(4140) and Y(3930) approximately
equal to that between  and 
M Y(4140)  M Y (3930)  M   M 
 Y(4140) and Y(3930) are close
to the thresholds of D*s D*s and
D* D* , and satisfy an almost
M  4143.0  2.9  1.2 MeV
+8.3
=11.7-5.0
 3.7 MeV
C parity: +
7
G parity: +
exact mass relation
M Y(4140)  2 M D*
s
M  3914.6
3.8
3.4
( stat )  2.0(syst ) MeV
 M Y (3930)  2 M D*  90 MeV
=34-8+12 ( stat )  5( syst ) MeV
新强子态唯象理论进展
刘翔 @ 兰州大学
Explanation of Y(4140) and Y(3930)
Y (4140) is a D*s D*s molecular state
Y(3930) is its D*D* molecular partner
Liu & Zhu, PRD80, 017502 (2009)
Mahajan, PLB679,228 (2009)
Branz, Gutsche, Lyubovitskij, PRD80, 054019 (2009)
Dynamics calculation:
Liu, Luo, Liu, Zhu, EPJC61, 411-428 (2009)
Ding, EPJC64, 297-308 (2009)
Select Rule
 The possible quantum numbers of
the S-wave vector-vector system are


Other interpretations:

J  0 ,1 , 2 .
P
Dynamically generated resonances
 However for the neutral D*D* system
with C=+, we can have
J P  0 , 2
Molina, Oset, arXiv:1001.3005 [hep-ph]
Tetraquark state
Stancu, arXiv:0906.2485 [hep-ph]
since C=(-1) L  S and J=S with L=0.
8
新强子态唯象理论进展
刘翔 @ 兰州大学
Decay Patterns of Y (4140) and Y (3930)
Open charm and hidden
charm two-body decays
Radiative decays
Liu & Ke, PRD80, 034009 (2009)
Liang, Molina, Oset, arXiv:0912.4359 [hep-ph]
The open-charm decay widths are comparable
to the hidden-charm decay width
Such a D-wave decay
width should be much
smaller than that for
the above hidden
charm S-wave decay
mode!
S-wave
D-wave
Liu, PLB680, 137 (2009): exclude P-wave
charmonium explanation for Y(4140)
9
新强子态唯象理论进展
刘翔 @ 兰州大学
The charmonium-like states in  fusion process
Phys.Rev.Lett.96:082003,2006
Phys.Rev.Lett.104:092001,2010

'
c2
Z(3930)
X(3915)
M  3929  5  2 MeV
 =29  10  2 MeV
M ( J /) GeV
Phys.Rev.Lett.104:112004,2010
arXiv:1002.0281 [hep-ex]
X(4350)
M  4350.6 4.6
5.1  0.7 MeV
 =13+18
9  4 MeV
Z(3930)
M  3926.7  2.7  1.1 MeV
 =21.3  6.8  3.6 MeV
10
新强子态唯象理论进展
刘翔 @ 兰州大学
11
新强子态唯象理论进展
刘翔 @ 兰州大学
Charmed-strange state
Phys.Rev.Lett.97:222001,2006
Phys.Rev.Lett.100:092001,2008
J P  1
DsJ (2860)
DsJ (2710)
Phys.Rev.D80:092003,2009
DsJ(2710)
hep-ex/0608031
Belle
DsJ(2860)
DsJ(3040)
12
新强子态唯象理论进展
刘翔 @ 兰州大学
Explanations of DsJ (2710)
 cs :
Mixing of | 23 S1 and |13 D1
Close, Thomas, Lakhina, Swanson, PLB647, 159 (2007)
Li, Ma, Liu, EPJC51, 359 (2009) Regge phenomenology
Zhong, Zhao, PRD81, 014031 (2010) Constituent quark model
Li, Ma, PRDD81, 014021 (2010) QPC
 cs (23 S1 ) : The first radial excitation of 1- c s state
Zhang, Liu, Zhu, EPJC50, 617 (2007)
Obtained ratio
of D*K/DK is
consistent with
experimental
data.
QPC
Matsuki, Morii, Sudoh, EPJA31, 701 (2007)
Colangelo, De Fazio, Nicotri, Rizzi, PRD77, 014012 (2008)
D* K / DK  0.91  23 S1
D* K / DK = 0.043  13 D1
Phys.Rev.D80:092003,2009
Chen, Wang, Zhang, PRD80, 071502 (2009)
Wang, Zhang, Wang, PLB681, 326 (2009) B decay+BS equation
 cs :
13 D1
Zhang, Liu, Zhu, EPJC50, 617 (2007)
QPC
Wei, Liu, Zhu, PRD75, 014013 (2007) D-wave cs
Shan, Zhang, arXiv:0805.4764, arXiv:0904.2453
QSR
Mass loaded flux tube model
 Mutiquark
1D assignment
to DsJ(2710)
can be
excluded.
Vijande, Valcarce, Fernandez, PRD79, 037501 (2009)
13
新强子态唯象理论进展
刘翔 @ 兰州大学
Explanations of DsJ (2860)
 The first radial excitation of the D*s0 (2317): J p  0
van Beveren, Rupp, PRL97, 202001 (2006) RSE model
Close, Thomas, Lakhina, Swanson, PLB647, 159 (2007)
Zhang, Liu, Zhu, EPJC50, 617 (2007) QPC
Matsuki, Morii, Sudoh, EPJA31, 701 (2007)
It can be fully excluded
since DsJ(2860)->D*K
channel was observed
ar BaBar
 cs : |13 D3  J p  3
Zhang, Liu, Zhu, EPJC50, 617 (2007)
QPC
Colangelo, De Fazio, Nicotri, PLB642, 48 (2006)
Effective Lagrangian
Li, Ma, Liu, EPJC51, 359 (2009)
Regge phenomenology
Zhong, Zhao, PRD81, 014029 (2010) Constituent quark model
Shan, Zhang, arXiv:0805.4764, arXiv:0904.2453
Chen, Wang, Zhang, PRD80, 071502 (2009) Mass loaded flux tube model
Li, Ma, PRDD81, 014021 (2010) QPC  D*K/DK=0.8
 Mutiquark
Vijande, Valcarce, Fernandez, PRD79, 037501 (2009)
 Two Overlapping resonances ( radially excited 0+ and 2+ cs states) at 2.86 GeV
van Beveren, Rupp, arXiv:0908.1142 [hep-ph]
 Mixture of charmed-strang states
Zhong, Zhao PRD81, 014031 (2010)
Li, Ma, PRDD81, 014021 (2010)  J P  1 : Mixing of | 23 S1 and |13 D1
D*K/DK=0.36, which is
smaller than experimental
value
Babar data
Phys.Rev.D80:092003,2009
Ratio of D*K/DK
consistent with
experimental
data
DsJ (2710)
14
新强子态唯象理论进展
刘翔 @ 兰州大学
2P cs state assignment to DsJ (3040)
2S state
DsJ(2710): 1-
D* K
DK
Sun, Liu, PRD80, 074037
J P  1 ,0 , 2 ,...
1D state
DsJ(2860)
Matsuki, Morii, Sudoh, EPJA31, 701 (2007)
DsJ (3040) is the first radial excitation of DsJ (2460)
Chen, Wang, Zhang, PRD80, 071502 (2009) A semi-classic flux tube model
15
Zhong, Zhao, PRD81, 014031 (2009)
Constituent quark model with effective Lagrangian
Colangelo, Fazio, arXiv:1001.1089 [hep-ph]
Effective Lagrangian approach
新强子态唯象理论进展
刘翔 @ 兰州大学
Bottom-strange state
The situation of bottom-strange meson is similar to that
of charmed-strange meson before 2003
Phys.Rev.Lett.100:082001,2008
Strong decay
Luo, Chen, Liu, PRD79, 074020 (2009)
CDF
[23] Godfrey, Kokoski, PRD43, 1679 (1991)
[24] Eichten, Hill, Quigg, PRL71, 4116 (1993)
[27] Falk, Mehen, PRD53, 231 (1996)
[29] Colangelo, De Fazio, Ferrandes, NPB. proc. Suppl.163, 177 (2007)
[31] Zhong, Zhao, PRD78, 014029 (2008)
Phys.Rev.Lett.100:082002,2008
D0
m  5839.6  1.1(stat )  0.7(syst ) MeV
16
Semileptonic
decay
新强子态唯象理论进展
Luo, Chen, Liu, Zhu, EPJC60, 403 (2009)
刘翔 @ 兰州大学
Y(2175)-Y(4260)-Y(10870)
PRD74, 091103 (2006)
PRL100, 102003 (2008)
PRD80, 031101 (2009)
BES
[1] BaBar, PRD74, 091103 (2006)
[2] BES, PRL100, 102003 (2008)
[3] BELLE, PRD80, 031101 (2009)
[4] BES, PLB685, 27 (2010)
[5] BaBar, PRD77, 092002 (2008)
17
新强子态唯象理论进展

Y(2175)
刘翔 @ 兰州大学
Y(4260)
J /
PRL 99, 182004 (2007)
PRL 95,142001(2005)
First Y(4260)
(2S)
2-BW fit with interference
• two solutions: different
peak cross sections
Y(4008)
7.4σ
8σ
233 fb-1
PRD74,091104R(2006)
5.4σ
18
Y(4260)
550 fb-1
ed
m
r
i
f
Con
PRL 96,162003(2006)
11σ
+ J/00 (5.1σ)
13.3 fb-1
新强子态唯象理论进展
刘翔 @ 兰州大学
Y(10870) (nS )
Phys.Rev.Lett.100:112001,2008
The measured width of Y(10870)  (1S,2S)  
is 2 : 3 order larger than those of
(nS)  (mS)   (n=2,3,4 and m<n)
Energy scan above Υ(4S) to
search for counterpart of
Y(4260) in bottomonium sector:
study cross section of
e+e → Υ(nS)π+π, (n=1, 2, 3)
New bottomoniumlike state
or anoumalous large
Υ(5S) → Υ(nS)ππ decay
Υ(5S) : m=10.865 GeV
Г=110 MeV
arXiv:0810.3829
19
新强子态唯象理论进展
刘翔 @ 兰州大学
Y(2175)
 

Strange

Y(4260)
Charm
J /  
Y(10870)
Bottom
(nS )  
Hybrid ccg
ss (23 D1 )
Ding, Yan, PLB657, 49
Hybrid ssg
Ding, Yan, PLB650, 390
Three-body system  KK
Zhu, PLB625, 212
Kou, Pene, PLB631, 164
Close, Page, PLB628, 215
Three-body system J/ KK
Torres et al., PRD80, 094012
Torres et al., prd78, 074031   bound state
c c
 bound state
Qiao, PLB639, 263
Klempt, Zaitsev, PR451, 1 Tetraquark [cs][cs]
Tetraquark ssss
Maiani et al. PRD72, 031502
Wang, NPA791, 106
Molecular state
Chen, Liu, Liu, Zhu
Liu, Zheng, Li, PRD72, 054023
PRD78, 034012
Yuan et al., PLB634, 399
20
新强子态唯象理论进展
(5S) + FSI
Meng, Chao, PRD77, 074003
PRD, 78, 034002, PRD78, 074001
Hybrid bbg
Olsen, arXiv:0801.1153
Godfrey, Olsen, ARNPS58, 51
 b  b bound state?
Tetraquark [bs][b s]
Ali et al. arXiv:0912.5016
PLB684, 28
刘翔 @ 兰州大学
Summary
 Charmonium-like state X, Y, Z
 Distinguish the conventional charmonium state and exotic states
 Above the thresholds of a pair of charmed mesons
Important non-perturbative effect
Coupled-channel effect
 Mass spectrum + Production + Decay
 More experimental information is needed
 Charmed-strange meson
DsJ(3040) 2P state (1+ state in S doublet)
Four states
DsJ(2860)+DsJ(2710) ----- 2S and 1D states
Six states
The experimental search for charmed-strange meson with high radial
excitation
21
新强子态唯象理论进展
刘翔 @ 兰州大学
 Bottom-strange meson
 Bs1(5930)+Bs2(5940)
2P states in T doublet (1+,2+)
 Two 2P states in S doublet (0+, 2+) are missing
 Nowadays, the situation of bottom-strange meson family is very similar
to that of charmed-strange meson family before 2003
Future experiments LHCb?
 Y(2175) Y(4260) Y(10870)
 Similar decay channel
phi pi pi
J/psi pi pi Upsilon(nS) pi pi
 Similar theoretical explanation Hybrid
Mutiquark state Molecular state
 Distinguish different theoretical assignments
Y(2175)
BESIII
Y(4260)
Exotic state? Other mechanisms?
Y(10870) Upsilon(5S)?
22
exotic state?
新强子态唯象理论进展
刘翔 @ 兰州大学
New hadron state: an active
research field in hadron physics
BESIII
2003
Y(4260)
DsJ(2317)
DsJ(2460)
X(1860)
2010
Charmonium-like states X, Y, Z
Charmed-strange meson DsJ
Bottom-strange meson BsJ
Light hadrons X(1860), X(1835),
Y(2175) ……
Super B
PANDA
LHCb
+ ……
More efforts: theoretical work + experiment
23
新强子态唯象理论进展
刘翔 @ 兰州大学
Thank you
for your
attention!
Backup slides
2
新强子态
刘翔 @ 兰州大学
The low mass puzzle of DsJ (2317) and DsJ (2460)
Phys.Rev.Lett.90:242001,2003
Experimental masses are 100 MeV lower than the expected
values in quark models
DsJ(2317)
S. Godfrey and R. Kokoski, PRD 43, 1679 (1991); S. Godfrey and N. Isgur, PRD 32,
189 (1985); M. Di Pierro and E. Eichten, PRD 64, 114004 (2001)
Four-quark state?
Barnes, Close, Lipkin PRD68, 054006 (2003)
Cheng, Hou, PLB566, 193 (2003)
Chen, Li, PRL93, 232001 (2004)
Coupled-channel effect plays an important
role to understand the low mass puzzle
Phys.Rev.D68:032002,2003
DsJ(2460)
van Beveren, Rupp, PRL91, 012003 (2003)
EPJC32, 493 (2004)
Dai, Li, Zhu, Zuo,
EPJC55, 249 (2008)
Liu，Liu，Zhu
PRD79, 094026 (2009)
Charmed-strange
C
RSE
QSR
CHPT
S
Godfrey, PLB568, 254 (2003)
Colangelo, De Fazio, PLB570, 180 (2003).
Dai, Huang, Liu, Zhu, PRD68, 114011 (2003)
13
新强子态唯象理论进展
刘翔 @ 兰州大学
arXiv:0808.1543
Y(4260)
e+e–→J/ψπ+π– γISR
Y(4260) ... Y(4008)?
Y(4008)
Br(J/ψπ+π–)Γee , eV
Solution1 Y(4008)
Solution2
< 0.7 90% CL
Solution1 Y(4260)
Solution2
7.5±0.9±
0.8
Absence of open charm production
is inconsistent with conventional charmonium
21
新强子态唯象理论进展
刘翔 @ 兰州大学
PRD 78,
014032
(2008) (2007)
PRL
98, 212001
Y(4360)→ψ(2S)ππ
Y(4360)
Y(4660)?
Y(4660)
6.1σ
Combined
fit to
+
–
e e →ψ(2S)
BaBar&Belle
+π
– –γ
+
π
data on e e →(2S)
ISR
+ π– γ
πY(4360),
ISR
298 fb-1
Y(4660) ...
Best measurements of Y(4360) and Y(4660)
PRL 99, 142002 (2007)
2-BW fit with interference
Assume all the
cross sections areY(4660)
due to
Y(4360)
Y(4360) and Y(4660)
added coherently
5.8σ
8σ
Br(ψ(2S)π+π–)Γee , eV
Solution1
Solution2
Y(4360)
Y(4660)
670 fb-1
Absence of open charm production
is inconsistent with conventional
charmonium