1. from Belle, BaBar and CLEO
Results on Rc
from Belle, BaBar and CLEO
Galina Pakhlova
ITEP, Belle collaboration

2. Historical remarks on inclusive measurements
 states were discovered at e+e– colliders
(4415) MARK-I 1976, DASP 1978
(3770) MARK-I 1977, DELCO 1978, MARK-II 1980, BESII 2005
(4040) and (4160) DASP 1978
Total cross section e+e–  hadrons
Crystal Ball 1986
BESII 2005
CLEO 2009

3. Exclusive measurements of  state decays
Only (3770)
non-DD decays problem
The single measurement of D and D* meson production
at Ecm= GeV Phys.Lett.B 69,
The single measurement of Λc production at Ecm= 5.2 GeV Phys.Rev. Lett. 44,
BESII fit of R spectrum
Phys.Lett.B660,
All possible two-body decays of
ψ(3770), ψ(4040), ψ(4160), ψ(4415)
model-dependent results
Resonance shapes
Interference term
Rres=RBW+Rint
Phys.Lett.B660,315(2008)

4. Not only B-Factories but Charm-Factories as well
Luminosity at B factories
Not only B-Factories but Charm-Factories as well 4

6. ISR measurements at B-factories
Fixed quantum numbers of final state JPC = 1– –
Study of open charm final states from threshold in wide energy region
Huge accumulated luminosity at B factories
Limited statistics
strong electromagnetic suppression
typical events topology: fast photon with small pt
Specific reconstruction methods
e.g. D+D*– & D*+D*–
partial reconstruction of D*– to increase efficiency by 10-20
reconstruction of ISR photon
measurements of recoil mass against γISR ≡ mass of D(*)+D*–
translation of D(*)+D*– mass spectrum to cross section
e.g. D+D–
full reconstruction of hadronic part
no reconstruction of ISR photon

7. Two-body final states

8. Belle, BaBar, CLEO: σ(e+e− →DD)
Phys.Rev. D76, (2007)
Phys.Rev. D77, (2008)
Phys.Rev. D80, (2009)
CLEO: narrow range GeV
no radiative corrections
problem of direct comparison with B-factories results
Wide structure near 3.9 GeV
agreement with coupled channel model Structure at GeV
(4040)? (4160)?
First hint of (4415) →DD
Good agreement between
Belle и BaBar

9. Belle, BaBar, CLEO: σ(e+e−→D(*)D*)
Phys.Rev. D79, (2009)
Phys. Rev.Lett. 98, (2007)
Good agreement between Belle и BaBar
Belle measurements more accurate than BaBar
Phys.Rev. D80, (2009)
ψ(4160)
ψ(4040)
CLEO: GeV
no radiative correction
problem of direct comparison with B-factories results

10. Energy scan with high accuracy but in narrow region 3.97 - 4.26 GeV
e+e– → Ds(*)+Ds(*)–
Ds+Ds*–
Ds+Ds–
Ds*+Ds*–
The single measurement of CLEO 2009
Energy scan with high accuracy but in narrow region GeV
Problems
Cross sections of charm strange mesons were found to be order of magnitude less than cross sections of D(*)D(*)
Ds* Dsγslow
very low efficiency of soft photons at threshold
multiple counting due to lots of soft photons in event

11. Belle measurements of e+e– → Ds(*)+Ds(*)–
Full reconstruction method similar to DD
Ds*+Ds*–
Ds+Ds–
Ds+Ds*–
(4415)
(4160)
(4040)
Sum of e+e– → Ds(*)+Ds(*)–
(4040)
(4160)
(4415)
Y(4260)
Ds+Ds–
peak at threshold near (4040)
Ds+Ds*–
peak at threshold near (4160) and (4415)
dip near Y(4260) mass

12. Belle, BaBar, CLEO: e+e– → Ds(*)+Ds(*)–
BaBar: Bin size of 100 MeV is too large to observe relatively narrow structures
Belle & BaBar are in agreement within errors
CLEO: GeV
no radiative corrections
Ds+Ds*–
Ds+Ds–

13. Three-body final states D0 D(*)− π+
Full reconstruction method

14. Cross section of e+e− D0D–+
670 fb-1
Phys.Rev.Lett.100,062001(2008)
(4415)D0D–+
M = 4411 ± 7 МэВ
Γtot = 77 ± 20 МэВ
Nev= 109 ± 25
In agreement with BES
Phys.Lett.B660,315(2008)
PDG06, Barnes at.al
Phys. Rev. D72, (2005)
σ(e+e–→ψ(4415))×Br(ψ(4415)→DD2(2460))×Br(D2(2460) →Dπ) = (0.74 ± 0.17 ± 0.07)nb
Br((4415)  D(D)non D2(2460))/Br((4415) DD2(2460))<0.22

15. Cross section of e+e− D0D*–+
ψ(4415)
Upper limit
Y(4260)
ψ(4415)
Phys.Rev.D 80, (2009)
σ(e+e–→ψ(4415))×Br(ψ(4415)→D0D*–π+)< 0.76 nb at 90% CL
Br(ψ(4415)→ D0D*–π+) < 10.6 % at 90% CL
UL at 90% CL

16. First final state with charm baryons
670 fb-1
X(4630)
8.2σ
Phys.Rev.Lett.101,172001(2008)
e+e–→Λc+Λc–
X(4630) ≡ Y(4660)? JPC=1– –
e+e–→Λc+Λc–
(5S) or (4D) J.Segovia, at al
(6S) B.Q.Li and K.T.Chao
influence of (3D) E.Beveren, G.Rupp
(2S)f0(980) molecule F.K.Guo et al
tetraquark D.Ebert et al
hexaquark M.Abud,F.Bucella, F.Tramontano
charm baryonium G.Gotugno, R.Faccini, A.Polosa
baryon-antibarion production via (4S) intermediate state
Yu.Simonov hep-ph

17. Exclusive cross sections contribution to the total cross sectionDD
DD*
D*D*
DDπ
Exclusive cross sections contribution to the total cross section
DD*π
ΛcΛc
DsDs +DsDs* +Ds*Ds*
Contributions of D+D*–, D*+D*–, D0D–π+ and D0D*–π+ are scaled following isospin symmetry

18. In conclusion...

19. Search for charmonium-like states
Y family
no peaks near Y states mass in exclusive open charm cross sections
X(4630) ?
minima near Y(4260) mass in cross sections of e+e– → D*+D*–, Ds(*)+Ds(*)–
predictions of dominant decays of Y(4260)  DD(*)π were not confirmed
X(4630)
quantum numbers, mass and width are in agreement with Y(4660)
does not mean that X(4630) ≡ Y(4660)
lots of interpretations – absence of clear understanding of X(4630) nature

20. Status and perspectives
Almost all measured cross sections are included into Durham Hep Data Base
Parameters and branchings of observed decays of (4415), σ(ee D0D0)/σ(eeD+D−) for (3770), upper limits on YDD*π are included to PDG tables
Obtained results are important for physical programs of experiments at e+e– colliders
KEDR at VEPP-4M
BESIII at BEPCII
c-τ factory in Novosibirsk
Belle II at SuperKEKB
... and for theory

21. (4040)
(4160)
Y(4260)
Thank you!