1. Charm spectroscopy 1 A. Drutskoy University of Cincinnati
AAAA 1
A. Drutskoy
University of Cincinnati
Charm spectroscopy
American Physical Society Meeting
April 14-17, 2007, Jacksonville, Florida .
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy
A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

2. Outline CLEO 2 Meson classification, potential models.
AAAA 2
Outline
Meson classification, potential models.
Recent experimental results on excited D** production.
Experimental results and classification of DsJ mesons.
Charmonium state X(3872).
Charmonium states X(3940), Y(3940) and Z(3930).
New charmonium states Y(4260) and Y(4320).
New charm baryons.
Conclusions.
CLEO
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy
A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

3. Conventional and unconventional mesons
AAAA 3
Conventional and unconventional mesons
1. Conventional quark- antiquark mesons (qq).
2. Glueballs (gg, ggg). Lightest glueballs JPC = 0++ and 2++.
3. Hybrid mesons (qqg). Ground states JPC = 0- +, 1- +, 1- -, 2- +.
4. Tetraquarks (qqqq). Large binding energy. Non-qq flavor?
5. Molecular states (qq qq). Small binding energy. Deuteron-like.
6. Mixture of these states.
These states can be separated using information on masses,
widths, quantum numbers, production and decay modes (rates).
Theoretical calculations, potential models, lattice calculations.
Coupled-channel effects. If Mres close to M1+M mass shift?
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy
A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

4. Potential models, energy splitting
AAAA 4
Potential models, energy splitting s1 s2 L s1 s2 Jq
S12 L
(L S2) S1
L (S1 S2)
Jq is a good quantum number => separated D(s) meson spin-doublets: (0-,1-), (0+,1+), (1+,2+).
Energy splitting: singlet and triplet. 1- cc 1- cq Y’ 2S 2S 0- 0-
h’c
Jq=3/2
Jq=1/2 2+
Ds2 2+
cc2
Mass 1+ 1+ 1+ 1P
L=1 1+ 1P
L=1
cc1
D’s1 hc
Ds1 0+ 0+
cc0
D’s0 1S 1S 1- 1-
J/Y
Ds*
L=0
L=0 0- 0- hc Ds
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy
A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

5. D**0 and D**+ meson searches
AAAA 5
D**0 and D**+ meson searches
D** mesons are studies
using fully reconstru-
cted B meson decays.
It provides strong
background suppression.
hep-ex/ (2006)
~388M
No restrictions on
D** quantum numbers
in B decays.
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy
A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

6. Orbitally excited D**0 and D**+ mesons
AAAA 6
Orbitally excited D**0 and D**+ mesons
(2465.71.80.8 ) MeV/c2
1.2
4.7
(49.73.84.1 4.9) MeV
Theory and experiment
are in good agreement
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy
A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

7. DsJ meson spectroscopy
AAAA 7
DsJ meson spectroscopy
Measured masses of DsJ(2317) and
DsJ(2460) are significantly lower than
those predicted in potential models.
DsJ(2573)
DsJ(2536) * Ds
DsJ(2460) Ds
DsJ(2317)
Their quantum numbers 0+ and 1+
are well established now.
Many theoretical papers have been published since 2003, trying to explain narrow DsJ(2317) and DsJ(2460) resonances: chiral partners, DK threshold effect, four-quark states? + +
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy
A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

8. New DsJ(2700) meson in B+ >D0D0K+ decay8
New DsJ(2700) meson in B+ >D0D0K+ decay
hep-ex/
449M BB
■ B+→D0DsJ(2700) ■ B+→ψ(3770)K+ ■ B+→ψ(4160)K+ ■B+→D0D0K+NR ■threshold contribution
DsJ(2700)
fitted B signal
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

9. DsJ(2700) helicity angle distribution9
DsJ(2700) helicity angle distribution
J=0 2/ndf = 185/5
J=1 2/ndf = 7/5
J=2 2/ndf = 250/5
JP=1- is favored.
cs radial excitation 23S1 ?
(predicted by potential models
at M~2720MeV) ?
or chiral symmetry doublet?
eff. corrected DsJ(2700) helicity
angle distribution
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

10. New DsJ(2860) meson in e+e- >D0K+X, D+K0X10
New DsJ(2860) meson in e+e- >D0K+X, D+K0X
hep-ex/
240 fb-1
103
BG subtracted
Strong peak at
2.573 GeV/c2
DsJ(2860)
Hint of a
broad state
at 2.69 GeV/c2
M(DK) (GeV/c2)
=>New resonance at 2.86 GeV/c2
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

11. DsJ meson spectroscopy
AAAA 11
DsJ meson spectroscopy
DsJ(2700) : Jp = 1-
Is Ds(2700) state the
radial excitation 23S1
(predicted by potential
models at M~2720MeV) ?
DsJ(2860) ??
Ds(2700) ?
DsJ(2573)
DsJ(2536)
DsJ(2860) -> D0 K+ (0-0- ) *
DsJ(2460) Ds
DsJ(2317) Ds
Is DsJ(2860) state the
radial excitation of DsJ(2317) ?
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy
A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

12. Charmonium spectroscopy
AAAA 12
Charmonium spectroscopy cc
hc’’
cc1’
hc’
hc2 Y2 Y3
MD*+MD
hc’
2MD Y’
cc2 hc
cc1
cc0
blue lines: predictions
black lines: measurements
J/Y hc
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy
A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

13. hc(1P1) and hc(2S) charmonium states13
hc(1P1) and hc(2S) charmonium states
Belle first observed c(2S)
at B-> K(KsK+-) and
then at e+e- -> J/ X
c(2S) was then confirmed
by CLEO and BaBar
With Inclusive c decay
CLEO
3.08M (2S) hc
15040 events
stat. sig. 3.8
B→ K(KsK+p-)
MPDG=3637.7±4.4MeV/c2
M(hc)=3524.90.70.4 MeV/c2
M(0 recoil) (GeV)
CLEO PRL 95 (2005)
CLEO PRD 72 (2005)
Belle PRL 89 (2002)
BaBar PRD 92 (2004)
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

14. X(3872) > J/y p+p- decay ’ 14 ’ X(3872) Events/10 MeV 220 pb-1
First observed by Belle in B± -> K±(J/+-).Then confirmed by CDF, D0 and BaBar.
Belle
X(3872)
304M B’s ’ ’
X(3872)
Events/10 MeV
220 pb-1
PRL 91 (2003)
PRL 93 (2004)
230 pb-1
X(3872)
X(3872)
BaBar
234M B’s
M(J/y p+p-)
PRL 93 (2004)
PRD 71 (2005)
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

15. Evidence for X(3872) > g J/y15
PRD 74 (2006) R
hep-ex/
287M BB
X(3872)
X(3872)
275M BB
MJ/ (GeV/c2)
MJ/ (GeV/c2)
19.4 5.7 events
stat. sig.: 3.4 
13.6 4.4 events
stat. sig.: 4.0 
Belle/BaBar average:
It suggests that C parity of X(3872) is +1
Low g J/y rate > bad candidate for c’c1 ??? (1++).
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

16. Evidence for sub-threshold X(3872) > w J/y16
Evidence for sub-threshold X(3872) > w J/y
hep-ex/
275M BB
10.63.6 events
4.3 
B±-> K±(J/ +-p0)
X(3872) : C=+1
M(+-0) (GeV/c2)
no signals for charged partners of X(3872) (BaBar)
no signal for X(3872) -> J/  (BaBar)
no evidence in  fusion and radiative production (CLEO)
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

17. X(3872) quantum numbers 17 1++ in B->X(3872)K decay 1++
AAAA 17
X(3872) quantum numbers
Angular distributions
in B->X(3872)K decay
X(3872) -> J/Y p+ p- :
g favors 1++.
hep- ex/
2/d.o.f=11/9
2/d.o.f=5/9
|cosl|
|cos|
1++
1++
Hint for B->X(3872)K with X(3872)->D0D0p0
favors 1++ (disfavors 2++) (next slide).
PRL 96 (2006)
Preference for high p+p- mass region.
Possible interpretation: X(3872)->J/y r
Possible X(3872) quantum numbers:
Jp=1++ (or 2-+) .
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy
A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004

18. X(3872) interpretation ? 18 DD* DD
< 1 MeV/c2
DD*
X(3872) DD
Interpretation of X(3872) is unclear. Molecular interpretation ?
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

19. Near threshold D0D0p0 enhancement in B >D0D0p0K19
Near threshold D0D0p0 enhancement in B >D0D0p0K
If X(3872) is a loosely bound S wave D0D0* molecule, an enhancement
in the near threshold D0D0* invariant mass spectrum is expected.
PRL 97 (2006)
23.4 5.6 events
6.4 
414 fb-1
M =   0.8 MeV/c2
-1.6 =
-3.6
If it is X(3872), J=2 is suppressed, JPC=1++ is favored.
X(3872) -> D0D0* production rate is large. This is difficult to
explain within molecular interpretation.
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

20. X(3872) in B0 and B+ decays Data are not in favor of this model. 20
PRD 73 (2006) R
6.1
2.5
232M BB
S-wave D0D*0:
E. Braaten et al.,
PRD 71, K+ D0
Data are not in favor
of this model.
X(3872) B+
D*0
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

21. Observation of X(3940) in e+e- > J/ X21
Observation of X(3940) in e+e- > J/ X
PRL 98 (2007)
J/y X e- e+
357 fb-1
M = (3943  6 6) MeV/c2
 < 52 MeV/c2 (90% C. L.)
Stat. sig. > 5.0 
Mrecoil(J/)
above DD and D*D thresholds
not seen in DD and J/y w
D*D is the dominant decay of X(3940)
> JPC = 1++ is preferred, candidate c’c1 (or hc(3S) ? ).
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

22. Y(3940) >w J/ near threshold peak in B >K w J/y22
Y(3940) >w J/ near threshold peak in B >K w J/y
PRL 94 (2005)
253 fb-1
2/d.o.f.=115/11
2/d.o.f.=15.6/8
stat. sig.=8.1
-> above D*D threshold
-> not found in DD or
D*D final states
M(wJ/)
If it is treated as
a S-wave BW:
M = 3943  11  13 MeV/c2
 = 87  22  26 MeV/c2
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

23. Search for ccJ via gg >DD and Z(3930)., 23
Search for ccJ via gg >DD and Z(3930).
PRL 96 (2006)
395 fb-1
N sig. = 64  18
stat. signif 
M=3929 52 MeV/c2
=29 102 MeV/c2
D0D0 + D+D-
Z(3930)
Angular analysis favors J=2
Good candidate for c’c2
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

24. Observation of Y(4260) in ISR events and B decays24
Observation of Y(4260) in ISR events and B decays
First observed by BaBar, then confirmed by CLEO and Belle.
PRL 95 (2005)
553 fb-1
Y(4260)
233 fb-1
Jp = 1--
hep- ex/
CLEO
4.9 sig.
3.1 sig.
B->Y(4260)K
Y(4260)-> J/y p+p-
PRD 73 (2006)
13.3 fb-1
PRD 74 (2006)
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

25. in e+e- -> hadrons (local minimum).25
What is the Y(4260) state ?
BaBar
CLEO III
Belle N
125  23 (~8)
(4.9)
165  24 ( >7s)
Mass(MeV/c2)
4259  8 +2
 4
4295 
Width(MeV/c2)
88  23 +6
 5
133
-4.2 -3 -6
-16 -6 -4
-25
~2.5s different
1-- state, but not seen
in e+e- -> hadrons (local minimum).
Interpretations:
Hybrid charmonium: Zhu, PLB 625 (2005) 212; Close & Page, PLB 628 (2005) 215;
Kou and Pene, PLB 631 (2005) 164; Luo and Liu, PRD 74 (2006) , …
Tetraquark: Ebert et al., PLB 634 (2006) 214; PRD73(2006)094501, ...
Molecules: Liu et al., PRD 72 (2005) (R); Yuan et al., PLB 634 (2006) 399
Qiao, PLB 639 (2006) 263, …
Conventional: F. J. Llanes-Estrada, PRD 72 (2005) (R), …
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

26. Observation of Y(4320) >p+p-y(2S) in ISR events26
Observation of Y(4320) >p+p-y(2S) in ISR events
M(+-(2S)
Y(4260)
Y(4350)
3-body phase space
hep- ex/
If this peak is a single resonance:
What is Y(4320)?
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

27. What are X(3872), Y(4260) and Y(4320) ? 27 DD* DD
Currently on market: X(3872) -molecular, Y(4260) & Y(4320) - hybrids
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

28. Charmed baryons 28 Many new charm baryon resonances hep-ex/0603052
Lc(2880)+
cx(3077)+
Lc(2940)+
cx(2980)+
287 fb-1
Mass(Λc+ K- +)(GeV/c2)
c(2980)+ :
M=2978.52.12.0 MeV/c2
=43.5 7.57.0 MeV/c2
Inclusive D0p mass spectrum
D0 mass sidebands
Belle<>BaBar
confirmed
Many new charm baryon resonances
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy

29. Conclusions 29 Many new open charm and charmonium (charmonium-like)
AAAA 29
Conclusions
Many new open charm and charmonium (charmonium-like)
states are observed (DsJ(2700), DsJ(2860), X(3872), X(3940),
Y(3940), Z(3930), Y(4260), Y(4320), baryons… ).
Interpretation of some of these states is not clear. New
ideas on market: four-quark states, molecular states, hybrids.
Maybe some mixture of two-quark and unconventional states?
It is important to determine quantum numbers of all observed
states. More decay channels should be studied.
It is theoretically difficult to explain some measurements
of production and decay rates for some (even conventional)
states (no time to discuss it in this talk).
Charm spectroscopy, APS meeting, Apr , 2007, Jacksonville, Florida, A. Drutskoy
A.Drutskoy, 32 Int'l Conference on HEP, August 16-22, 2004