Transcript Slide 1

1
A. Drutskoy
University of Cincinnati
Charm spectroscopy
American Physical Society Meeting
April 14-17, 2007, Jacksonville, Florida .
Charm spectroscopy,
APS meeting,
Apr 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
Outline
2
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 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
Conventional and unconventional mesons
3
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+M2
mass shift?
Charm spectroscopy,
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Potential models, energy splitting
s1
s2
L
s1
S12
4
Ls
2
(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.
Mass
2S
10-
Y’
cc
h’c
2+
1P
1S
L=0
L=1
10-
1+
hc
1+
0+
Charm spectroscopy,
2S
hc
APS meeting,
10-
cc2
cc1
cq
Jq=3/2
2+
Jq=1/2
1P L=1
1+
1+
Ds1
0+
cc0
1S
L=0
J/Y
Jq
Apr 14 -17, 2007,
10-
Ds2
D’s1
D’s0
Ds*
Ds
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A. Drutskoy
D**0 and D**+ meson searches
5
D** mesons are studies
using fully reconstructed B meson decays.
It provides strong
background suppression.
hep-ex/0611054(2006)
~388M
No restrictions on
D** quantum numbers
in B decays.
Charm spectroscopy,
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A. Drutskoy
Orbitally excited D**0 and D**+ mesons
(2465.71.80.8
1.2
4.7
6
) MeV/c2
(49.73.84.1 4.9) MeV
Theory and experiment
are in good agreement
Charm spectroscopy,
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A. Drutskoy
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*
Ds
DsJ(2460)
DsJ(2317)
Their quantum numbers 0+ and 1+
are well established now.
Many theoretical papers have been published since 2003, trying
+ (2317) and D+ (2460) resonances: chiral
to explain narrow DsJ
sJ
partners, DK threshold effect, four-quark states?
Charm spectroscopy,
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A. Drutskoy
New DsJ(2700) meson in
B+
>D0D0K+
8
decay
hep-ex/0608031
449M BB
■ B →D DsJ(2700) ■ B →ψ(3770)K ■ B →ψ(4160)K ■B →D D K NR
■threshold contribution
DsJ(2700)
+
0
+
+
+
+
+
0
0
+
fitted B signal
Charm spectroscopy,
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9
DsJ(2700) helicity angle distribution
J=0 c2/ndf = 185/5
J=1 c2/ndf = 7/5
J=2 c2/ndf = 250/5
JP=1- is favored.
eff. corrected DsJ(2700) helicity
angle distribution
Charm spectroscopy,
APS meeting,
cs radial excitation 23S1 ?
(predicted by potential models
at M~2720MeV) ?
or chiral symmetry doublet?
Apr 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
New DsJ(2860) meson in
e+e-
>D0K+X,
D+K0X
10
e  e   D 0 K  X , D 0  K  
e  e   D 0 K  X , D 0  K   0
hep-ex/0607082
103
e  e   D  K s0 X , D   K    , K s0    
240 fb-1
Strong peak at
2.573 GeV/c2
BG subtracted
DsJ(2860)
Hint of a
broad state
at 2.69 GeV/c2
M(DK) (GeV/c2)
=>New resonance at 2.86 GeV/c2
M ( DsJ (2860))  2856.6  1.5  5.0 MeV/c2
( DsJ (2860))  47  7  10 MeV/c2
Charm spectroscopy,
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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- )
Is DsJ(2860) state the
radial excitation of
DsJ(2317) ?
Charm spectroscopy,
APS meeting,
Ds*
Ds
Apr 14 -17, 2007,
DsJ(2460)
DsJ(2317)
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A. Drutskoy
12
Charmonium spectroscopy
cc
hc’’
cc1’
hc2 Y2 Y3
hc ’
h c’
MD*+MD
2MD
Y’
hc
cc0
J/Y
hc
Charm spectroscopy,
APS meeting,
cc1
cc2
blue lines: predictions
black lines: measurements
Apr 14 -17, 2007,
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A. Drutskoy
hc(1P1)
and hc(2S) charmonium states
Belle first observed hc(2S)
at B-> K(KsK+-) and
then at e+e- -> J/ X
 (2S )   hc  ( )(hc )
0
With Inclusive hc decay
CLEO
13
hc(2S) was then confirmed
by CLEO and BaBar
3.08M (2S)
hc
15040 events
stat. sig. 3.8
B→ K(KsK+)
MPDG=3637.7±4.4MeV/c2
M(hc)=3524.90.70.4 MeV/c2
M(0 recoil) (GeV)
CLEO PRL 95 (2005) 102003
CLEO PRD 72 (2005) 092004
Charm spectroscopy,
APS meeting,
Belle PRL 89 (2002) 102001
BaBar PRD 92 (2004) 142002
Apr 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
14
X(3872) > J/ +- decay
First observed by Belle in B± -> K±(J/+-).Then confirmed by CDF, D0 and BaBar.
Events/10 MeV
Belle
’
304M B’s
’
X(3872)
X(3872)
220 pb-1
PRL 91 (2003) 262001
230 pb-1
PRL 93 (2004) 072001
X(3872)
X(3872)
BaBar
234M B’s
M(J/ +-)
PRD 71 (2005) 071103
PRL 93 (2004) 162002
Charm spectroscopy,
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Evidence for X(3872) >

15
J/
PRD 74 (2006) 071101R
hep-ex/0505037
X(3872)
X(3872)
287M BB
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 
( X (3872)  J / )
 0.19  0.07
Belle/BaBar average:
 
( X (3872)    J / )
It suggests that C parity of X(3872) is +1
Low  J/ rate > bad candidate for c’c1 ??? (1++).
Charm spectroscopy,
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Apr 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
Evidence for sub-threshold X(3872) > w J/
16
hep-ex/0505037
275M BB
10.63.6 events
4.3 
B±-> K±(J/ +-0)
M(+-0) (GeV/c2)
X(3872) : C=+1
( X (3872)     0 J / )
 1.0  0.4  0.3
 
( X (3872)    J / )



no signals for charged partners of X(3872) (BaBar)
no signal for X(3872) -> J/ h
(BaBar)
no evidence in  fusion and radiative production (CLEO)
Charm spectroscopy,
APS meeting,
Apr 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
X(3872) quantum numbers
 Angular distributions
in B->X(3872)K decay
X(3872) -> J/Y + - :
g favors 1++.
hep- ex/0505038
1++
17
c2/d.o.f=11/9
|cosl|
1++
c2/d.o.f=5/9
 Hint for B->X(3872)K with X(3872)->D0D00
favors 1++ (disfavors 2++) (next slide).
|cosc|
PRL 96 (2006) 102002
 Preference for high +- mass region.
Possible interpretation: X(3872)->J/ r
Possible X(3872) quantum numbers:
Jp=1++ (or 2-+) .
Charm spectroscopy,
APS meeting,
Apr 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
X(3872) interpretation ?
18
< 1 MeV/c2
DD*
X(3872)
DD
Interpretation of X(3872) is unclear. Molecular interpretation ?
Charm spectroscopy,
APS meeting,
Apr 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
Near threshold
D0D00
enhancement in B
19
0
0
0
>D D  K
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) 162002
414 fb-1
• 23.4 5.6 events
• 6.4 
0.4  0.8 MeV/c2
2
M =3875.2
M
3875.4  0.7
0.7+0.3

0
.
9
MeV/c
-1.6
1.7
( X  D0 D *0 )
3.6
 9.4+3.1
=8.8
4.3
-3.6
( X  J / )
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,
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Apr 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
X(3872) in B0 and B+ decays
B  X (3872)K 
PRD 73 (2006) 011101 R
20
B0  X (3872)Ks0
6.1
2.5
232M BB
S-wave D0D*0:
R  0 .1
E. Braaten et al.,
PRD 71, 074006
0.13  R  B 0 B   1.10 at 90%C.L.
ΔM  2.7  1.3 0.2 MeV/c2
K+
D0
B+
D*0
Charm spectroscopy,
X(3872)
APS meeting,
Data are not in favor
of this model.
Apr 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
Observation of X(3940) in
e+e-
21
> J/ X
PRL 98 (2007) 082001
X
357 fb-1
e-
e+
J/
Mrecoil(J/)
M = (3943  6 6) MeV/c2
 < 52 MeV/c2 (90% C. L.)
Stat. sig. > 5.0 
above DD and D*D thresholds
D*D is the dominant decay of X(3940)
not seen in DD and J/ w
> JPC = 1++ is preferred, candidate c’c1 (or hc(3S) ? ).
Charm spectroscopy,
APS meeting,
Apr 14 -17, 2007,
Jacksonville, Florida,
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Y(3940) >w J/ near threshold peak in B >K w J/
PRL 94 (2005) 182002
22
253 fb-1
c2/d.o.f.=15.6/8
stat. sig.=8.1
c2/d.o.f.=115/11
-> above D*D threshold
-> not found in DD or
D*D final states
M(wJ/)
If it is treated as
a S-wave BW:
Charm spectroscopy,
M = 3943  11  13 MeV/c2
 = 87  22  26 MeV/c2
APS meeting,
Apr 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
23
Search for c,cJ via  >DD and Z(3930).
PRL 96 (2006) 082003
 N sig. = 64  18
 stat. signif. 5.3 
 M=3929 52 MeV/c2
 =29 102 MeV/c2
395 fb-1
D0D0 + D+D-
Z(3930)
Angular analysis favors J=2
Good candidate for c’c2
Charm spectroscopy,
APS meeting,
Apr 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
Observation of Y(4260) in ISR events and B decays
24
e e   ISR   J / ( J/ψ  e e or   )
 


 


First observed by BaBar, then confirmed by CLEO and Belle.
PRL 95 (2005) 142001
233 fb-1
Y(4260)
553 fb-1
Jp = 1--
hep- ex/0612006
CLEO
4.9 sig.
3.1 sig.
13.3 fb-1
PRD 74 (2006) 091104
Charm spectroscopy,
APS meeting,
B->Y(4260)K
PRD 73 (2006) 011101
Y(4260)-> J/ +Apr 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
25
What is the Y(4260) state ?
BaBar
CLEO III
125  23 (~8) 14.1 +5.2 (4.9)
N
-4.2
Belle
165  24 ( >7)
Mass(MeV/c2) 4259  8 +2
-6
4283 +17
4
-16
4295  10 -+10
3
Width(MeV/c2) 88  23 -4+6
70 +40
-25  5
133 26 +13
-6
~2.5 different
Interpretations:
1-- state, but not seen
in e+e- -> hadrons (local minimum).
•
Hybrid charmonium: Zhu, PLB 625 (2005) 212;
•
•
Molecules:
•
Close & Page, PLB 628 (2005) 215;
Kou and Pene, PLB 631 (2005) 164;
Luo and Liu, PRD 74 (2006) 034502, …
Tetraquark: Ebert et al., PLB 634 (2006) 214; PRD73(2006)094501, ...
Liu et al., PRD 72 (2005) 054023 (R); Yuan et al., PLB 634 (2006) 399
Qiao, PLB 639 (2006) 263, …
Conventional: F. J. Llanes-Estrada, PRD 72 (2005) 031503(R), …
Charm spectroscopy,
APS meeting,
Apr 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
Observation of Y(4320) >+-(2S) in ISR events
26
M(+-(2S)
Y(4260)
Y(4350)
3-body phase space
If this peak is a single resonance:
What is Y(4320)?
Charm spectroscopy,
APS meeting,
Apr 14 -17, 2007,
hep- ex/0610057
M  4324 24 MeV/c2
  172 23 MeV/c2
Jacksonville, Florida,
A. Drutskoy
What are X(3872), Y(4260) and Y(4320) ?
27
Y(4320)
Y(4260)
X(3872)
DD*
DD
Currently on market: X(3872) -molecular, Y(4260) & Y(4320) - hybrids
Charm spectroscopy,
APS meeting,
Apr 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
28
Charmed baryons
hep-ex/0603052
hep-ex/0606051
Lc(2880)+
cx(3077)+
Lc(2940)+
cx(2980)+
287 fb-1
Mass(Λc+ K- +)(GeV/c2)
0p mass spectrum
Inclusive
D0 mass D
sidebands
L c (2940)  :
M  2939.8  1.3  1.0 MeV/c2
  17.5  5.2  5.9 MeV/c2
Charm spectroscopy,
APS meeting,
Belle<>BaBar
confirmed
c(2980)+ :
M=2978.52.12.0 MeV/c2
=43.5 7.57.0 MeV/c2
Many new charm baryon resonances
Apr 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy
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 14 -17, 2007,
Jacksonville, Florida,
A. Drutskoy