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Evidence for new Charmonium-like States
from the BELLE Experiment
Jens Sören Lange
(GSI, Johann Wolfgang Goethe-Universität Frankfurt)
PANDA Collaboration Meeting
Dresden, March 10, 2006
1
KEK-B Asymmetric Accelerator
E(e–)=8 GeV, E(e+)=3.5 GeV Luminosity
start 06/1999
~1/fb per day
= 1.2 Mill. BB
integrated
BELLE 551 /fb
BABAR 324 /fb
CLEO ~10 /fb
peak
19.12.2005
L=1.63 x 1034 /cm2/sec
~63%
above design goal
Tsukuba, Japan
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 2
B factories are well suited for charm spectroscopy
• adjusted to Upsilon(4S), decays ~99% toBB
• ~10% of time s=10.52 GeV in non-resonant continuum
on-resonance:
~99% of B mesons
decay into charm particles
off-resonance:
cross section is high
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 3
On- vs. Off-Resonance: charmonium production
on-resonance off-resonance
J/ from B decay direct J/ production
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 4
J/ invariant mass
~8-10 MeV
s=10.58 GeV s=10.52 GeV
on-resonance off-resonance
J/ from B decays direct J/ production
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 5
Note
• traditional wisdom:
at e+e– machines one can only create
JP=1– charmonium states
(because e+e– * cc)
only true for tree level:
gluon radiation spin 0,1,2,3 ...
vs.
also: part of data is two-photon fusion
e+e– ** ... (spin 0,1,2)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 6
The BELLE Detector asymmetric
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 7
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 8
Example events with charmonium final states
J/e+e J/+
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 9
J/e+e–, +– invariant mass
8.9 MeV 8.5 MeV
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 10
Reconstruction of higher charmonium states
(2S)
cc1, cc2 → J/
→ J/ +-
cc1
cc2
keep in mind
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 11
Meson spectroscopy
• V(r) ~ a 1/r + b r
r small: Coulomb-like
n
r large: confinement
• excitations:
• radial n
• orbital L
• spin ,
• Spectroscopic Notations
n2S+1 L J L
JPC
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 12
Potential Model
terra nova
DD* threshold
´ DD threshold
c´ cc2
cc1
hc cco
J/ „ORTHO“
c „PARA“
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 13
The Fluxtube in a Meson
[ qq ] bound state
strong interaction strength
0.7 fm 1.0 fm 1.35 fm
Lattice QCD calculations
G. Bali, hep-lat/9409005
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 14
Highly Excited [ qq ] States as seen by Lattice QCD
• fluxtube becomes thinner and might break earlier
strong interaction strength
G. Bali, hep-lat/0510051
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 15
Are there maybe additional gluonic excitations ?
• glueballs [gg ]
or
hybrids [ccg ]
• only Lattice QCD
is able to answer
• hep-ph/0412158
note:
no 1++ glueball
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 16
c´ (21S0)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 17
c´ candidate seen 1982 by CRYSTAL BALL
• Phys. Rev. Lett. 48(1982)70
recoil
35925 MeV
(~50 MeV too low
for potential models)
• never confirmed
´X
J/X
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 18
Observation at BELLE 2002
• excited singulet charmonium c(2S)
• observation in B decays
• Phys. Rev. Lett. 89(2002)102001
• 44.8 Mill. BB
• m=365468 MeV
(close to potential models)
• c´ e+e– not allowed (spin 0),
c´ gg (hadronic) allowed
• charm strange dominant
hence search in channels
with Kaon final states
[s s]
here: Ks K
• note: ´ seen only 3 weeks after J/,
c´ 24 years after c
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 19
Confirmation by CLEO and BABAR
• not in B decay, but fusion
Phys. Rev. Lett. 92(2004)142001 Phys. Rev. Lett. 92(2004)142002
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 20
c´ observation in double charmonium production
3rd production mechanism J/
BELLE off-resonance
Phys. Rev. D 70(2004)071102
e+e cc cc recoil
recoil mass against J/
note:
charge conjugation c cc0 c(2S)
forbids J/ J/
(see also
PRD 70(2004)071102
for e+e–**
hypothesis)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 21
X(3872)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 22
The J/ +– final state
A golden event
of a CP violating decay
Bo J/ Kso
J/ +–
(here J/+–)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 23
Evidence for a new state X(3872)
‘(3686)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 24
X(3872) Confirmation
9.4
11.6
Phys. Rev. Lett. 91(2003)262001
152 Mill. BB
BABAR
hep-ex/0406022
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 25
Agreement among 4 Experiments
Average m=3871.90.5 MeV/c2
Widths consistent with resolutions
<2.3 MeV (BELLE)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 26
What is the X(3872) ?
X(3872)
DD* threshold
´ DD threshold
c´ cc2
cc1
hc cco
J/
c
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 27
What is the X(3872) ?
• final state J/
• m() clusters around mass
• enables identification of
C parity
for bosons, total wave function
must be symmetric
• I=1
L()=1, JPC()=1– – (-like)
CX(3872)= +
• I=0,2
L()=0, JPC()=0++
CX(3872)= –
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 28
BR is factor ~10
smaller than
XJ/+–
4
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 29
X(3872) possible quantum numbers
BKX decays
spin 0 spin-0 X
high L=2,3,... suppressed
but test anyway
consider D wave states (L=2)
2 13D2 2 m~3838 (predicted)
3 13D3 3 m~3849 (predicted)
should have a dominant radiative decay(s)
X cc1(13P1, 3511)
X cc2(13P2, 3556)
„easy“ L=2L=1 transitions
by emission
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 30
X(3872) possible quantum numbers
Test upon
2 13D2
‘(3686)
answer: no.
X(3872)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 31
X(3872) possible quantum numbers
Test upon
3 13D3
‘(3686)
answer: no.
X(3872)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 32
X(3872) possible quantum numbers
Remember:
above DD threshold
(3740 MeV)
but
XDD not observed
BR(XDD) / BR (XJ/+–) < 7
(90% CL)
BELLE, hep-ex/0307061
forbidden / suppressed ?
disfavours
[DD ] quantum numbers
JP=0++, 1– –, 2++, ...
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 33
Why is the X(3872) narrow ?
about one pion mass above DD threshold
and be narrow anyway ?
few states are predicted narrow
if decay into DD is blocked
J=1, if predicted mass below threshold
1+– 11P1
J=2, parity breaking
2– – 13D2 (2) , 2–+ 11D2 (2c)
J=3, angular momentum barrier
(13D3 must get rid of L=3 for decay to DD spin-0 spin0)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 34
X(3872) possible quantum numbers
• 0–+ and 1++ are still options
consider a 0–+ radial excitation
c´´(31S0,0+)
m~4060 in potential model
(predicted mass too high,
but consider anyway)
should be seen in fusion (as c , c´)
negative search
CLEO, Phys. Rev. Lett. 94(2005)0032004
• answer: no.
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 35
Does the X(3872) decay into DD(*) ?
NEW
DD not seen, but DD seen !
BR(BK X)BR(X+-J/) =1.31±0.24±0.13 10-5
BR(BK X)BR(XJ/) =1.8 ±0.6 ±0.1 10-6
BR(BK X)BR(XDD) =1.6 ±0.4 ±0.3 10-4
this is 12.55 x more than the original observation
so we can‘t say anymore that decay into DD* BELLE Preliminary
is (maybe) suppressed
• note: N=12.5±3.9
although D* D o
(>5)
X D D*
X D D
mean different decay dynamics
0- 1-
0- 0- 0-
orbital angular momentum L=1 !
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 36
X(3872) possible quantum numbers
1++ is a likely assignment.
Is there a 1++ ? Yes.
cc1´(23P1)
but inconsistent with potential model
m~70 MeV higher predicted
Preliminary conclusion:
the X(3872) might not fit into a naïve potential model
Not resolved yet.
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 37
X(3940)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 38
Revisited: double charmonium recoil mass (off-resonance)
L=101 fb-1 2002
2004 L=287 fb-1
L=155 2003
fb-1
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 39
Another one, X(3940)
350/fb
no signal of X(3872)
significant peak at M=3.9400.011 GeV/c2
N=14833 events (4.5)
width is surprisingly narrow <~ resolution (= 32 MeV)
background curve:
2nd order polynomial
plus D(*)D(*)J/ c cc0 c´
threshold term
so far only spin-0 particles
in recoil mass
c´´ ?
inconsistent to
potential model m~4060 MeV 2005
(should be accurate
for S=0, L=0)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 40
Does the X(3940) decay into DD(*) ?
BELLE, 357fb-1, hep-ex/0507019, subm. to Phys. Rev. Lett.
reconstruct J/ + one D
then investigate recoil mass
X(3940)→D D
not seen
X(3940)→D(*)D Mrec(J/ D)=M(D)
seen !
„normal“ charmonium (?)
Mrec(J/ D)=M(D*)
24.5±6.9
evts
5
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 41
Coming back to the X(3872) for a moment
Evidence for X(3872)+0 J/ (sub-threshold)
(hep-ex/0408116)
a virtual (782)?
12.4 ± 4.2 events
Br(X3J/) large (near max)
Br(X2J/) = 1.0 ± 0.5 isospin violation
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 42
Another one, Y(3940)
extend range to higher m(J/)
Phys. Rev. Lett. 94(2005)182002
253/fb
394311(stat.)13(syst.) MeV
width 872226 MeV
significance 8
fit: s-wave Breit-Wigner
plus phasespace-like
threshold function
let‘s try to be inventive:
not call it X
A charmonium thus high should
dominately decay into DD
(and not J/)
why is it blocked/suppressed ?
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 43
Investigate other possible decay modes
Y(3940)J/ is not seen
vs. : additional [ss] in wave function
might rule out tetraquark [cc ss] concept
PRL 93, 041801
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 44
Yet another one at same mass, Z(3930)
hep-ex/0507033
DD, D+D–
BELLE Phys. Rev. Lett. 96(2006)082003
280/fb
m=3931±4(stat)±2(syst) MeV
=20±8±3 MeV
5.5
can couple to 0,1,2
only candidates: n3P0 and n3P2
(excited S states known and
n3P1 dominately decays radiative, J((*))=1)
*(D)
J=0 flat
J=2 ~sin4*
might be 1st observed radial excitation
of a P charmonium state: 23P2 c'c2
(only n3S, n1S seen so far)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 45
Implications for PANDA
if parity +, then can be produced with 2 gluons: „enhanced“
1–
1+
J/,‘
Y(4260) X(3872)
X(3872) only seen in B decays
production of X(3872) at CBM (pp, SIS300)
might have similar cross section (~nb)
as PANDA
none of the new states has been
in the BELLE TDR
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 46
Conclusion
B factories observe several new states
c´ BELLE
D*(2308) BELLE
D1(2427) BELLE
DsJ(2317) BABAR
DsJ(2460) CLEO
X(3872) BELLE
X(3940) BELLE
Y(3940) BELLE
Z(3930) BELLE
c(2800) BELLE
hc CLEO
Y(4260) BABAR
some of them quantum numbers unassigned yet
with increasing statistics additional observation are uninevitable
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 47
Another one, Y(4260)
BABAR hep-ex/0506081
initial state radiation events e+e J/+–
(tag: undetected parallel to beam axis in beampipe)
211/fb
mass 42598+2–6 MeV, width 8823+6–4 MeV
significance >8
(4040), (4160), (4415) not seen
intriguing fact:
again close to a threshold
D*o(2007) D2*o (2460)
tentative assignment
(based upon production
mechanism)
1– –
note: allowed for DD
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 48
Y(4260) not seen in energy scans
e+e– inclusive hadrons
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 49
Y(4260) Confirmation by CLEO
energy scan
not inclusive hadrons, but J/+–
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 50
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 51
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 52
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 53
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 54
hc (1P1)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 55
D**
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 56
D**
• assume heavy quark symmetry
mcharm
• light quark couples to L first
• then
L=1 states are 2 doublets
jq=1/2
broad (decay by S wave)
jq=3/2
narrow (decay by D wave)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 57
D**
• BELLE observes the two broad D** (jq=1/2) states D+K+
Phys. Rev. D69(2004)112002 D*+Do+
65.4 Mill. BB DoK+
• mass width DoK++
D*0(J=0) 2308171528 MeV 276211860 MeV
D´1(J=1) 2427262015 MeV 384+107-752470 MeV
D2* can decay
to D and D*
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 58
DsJ
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 59
Unexpected observations in 2003 in e+ecc
• BABAR observed DsJ+(2317)Ds+ o Phys. Rev. Lett. 90(2003)242001
• CLEO observed DsJ+(2460)Ds+*o Phys. Rev. D 68(2003)032002
• Ds final state
> most probable assignment
[c s] L=1 states
• narrow (<4.6 MeV and <5.5 MeV, respectively)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 60
Confirmation
• BELLE confirmed both
and observed DsJ+(2460)Ds+ Phys. Rev. Lett. 92(2004)012002
• seen in both production mechanisms
• e+ecc
• B decay > important for determination of quantum number
not Ds* !
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 61
DsJ quantum numbers
• observation in B decays enables helicity analysis (fixed initial state)
JP=0+ JP=1-
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 62
Compare D and Ds systems
• should be similar (except smaller mass splitting jq=1/23/2
due to s quark mass
• why are the Ds jq=1/2 states narrow (and the D states broad) ?
isospin violation (from I=0 to I=1)
• but measured DsJ masses >100 MeV lower than potential model
Theory
Experiment
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 63
Charmed Baryons
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 64
Charmed Baryons
• (u/d, u/d, c) baryons
known states
c(2455)
I(JP)
c(2285) 0(1/2+)
c(2455) 1(1/2+)
= isospin excitation
c(2520) 1(3/2+) c(2520)
= spin excitation
no orbital excitations
observed yet
• cpK–+
cpKs
c+
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 65
Isotriplet
281/fb
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 66
co,+
• BELLE 140/fb
• Phys. Lett. B 605(2004)237
• three new decay modes (of seven observed)
• search for co,+ excited states is underway
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 67
Additional Slides
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 68
X(3872)J/+– candidate selection
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 69
Title
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 70
Lattice QCD
• hep-ph/0412158
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 71
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 72
On- vs. Off-resonance
on-resonance off-resonance
(B decay)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 73
BELLE
B factory detectors
CLEO
BABAR
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 74
since
1999
before
1999
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 75
Another DsJ ?
• SELEX, 600 GeV hyperon beam (~50% -) on Cu target
• peaks at m~2632 MeV seen in both
m(Ds+) and m(Do K+) (where known Ds2(2573) is seen as well)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 76
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 77
Investigation of the system (cont’d)
M() can distinguish -J/ S- & P-waves
S-wave: c2/d.o.f. = 43/39 P-wave: c2/d.o.f. = 71/39
(ignoring D-wave) (ignoring F-wave)
BELLE BELLE
~q*(J/) ~q*3(J/)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 78
Investigation of the system (cont’d)
M() can distinguish -J/ S- & P-waves
Indication for S-wave supported by CDF
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 79
Double charmonium production
e+e– cccc X
off-resonance (direct production)
even production of 4 charm quarks seen
e+e– cccc X
cross section is enhanced
e.g. e+e–J/c
~ factor 12.8 higher than expected
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 80
hep-ex/0206002
The direct J/ enigma PRL 89(2002)102001
Theorie Experiment
2 gluons:
dominant ~ 1 pb negligible color-singlet or
color-singlet
dominant for high p*(J/)
~ 0.5 pb
p*(J/)
not seen 1 gluon
only color-octet
0 1 2 3 4 5 GeV/c
suppressed
(2 x charm quark mass) dominant ~ 80%
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 81
• 3 enigmä:
- cross section factor ~10 too high
- 60% of cc is rather cccc (contradicts 1/S)
- no color-8 contribution seen
• color-8 can give more charmonium
a bound [cc] must be colorless
but an intermediate cc pair might be color-8
(in other words, it is colored)
the color-8 state radiates a gluon, and thus becomes colorless
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 82
Is it QED and not QCD ?
Braaten et al. noticed
Phys. Rev. Lett. 90 (2003) 162001
that in none of
the previous calculations
2 photon diagrams
were taken into account
But this would mean:
we must see: J/ J/
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 83
Are there coupled channel effects ?
• beyond naïve potential model
• Brambilla et al., hep-ph/0412158
• intriguing fact
X(3872) mass is very close
toDD* threshold
within errors +0.51.1 MeV
• near threshold
Schrödinger states are not pure
potential model eigenstates,
but
(sub-threshold, virtual)
• induces mass shifts
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 84
hc also observed
• CLEO hep-ex/0505073
• e+e–(2S)ohc, hcc
• 3.08 x 106 (2S) decays
• m=3524.40.60.4 MeV
• significance > 5
• mass consistent with spin-weighted average of ccJ
(and only 1.8 MeV lower than non-confirmed E760 signal in 1992)
mrecoil(o)
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 85
Cross sections at RHIC.
SPS s=17.8 GeV, RHIC s=130, 200 GeV
(cc)~factor 102, (bb)~factor 103 higher
cc
bb
(pp-->cc)[b]
pQCD
R. Vogt
hep-ph/0205330
100 1000 10000
s [GeV]
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 86
DD
• X(3872)
-> DD not seen
-> DD* not seen
-> DD seen
• Y(3940) = the J/Psi Omega enhancement
-> DD not seen
-> DD* not seen
unlikely to be seen because J/Psi Omega decay is so strong
• X(3940)
-> DD not seen (in J/Psi D recoil)
-> DD* seen !
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 87
test
Jens Sören Lange Resonances Results from BELLE PANDA, Dresden, 10.03.2006 88
