1. CONVENTIONAL CHARMONIA
Section Editors
BaBar: Riccardo Faccini
Belle: Pavel Pakhlov
Theory: Nora Brombilla

2. Outline of the section.
0. Introduction
Observation of new conventional charmonium states
1.1 c(2S)
1.2 c2 (2P)
1.3 X(3940)/X(4160)
1.4 X(4630)
2. Observation of new decay modes of known charmonia
2.1 c  
2.2 ψ(4415)  DD2
2.3 ψ(4040/4160)  DD, DD*, D*D*
3. Measurements of parameters (mass, width, Br)
3.1 c mass and width, transition FF
3.2 J/ψ: Γee, Γtot from ISR
3.3 c0 and c2
3.4 ψ(3770) mass and width
4. Production
4.1 in two body B-decays (interfere with B  charm)
4.2 in ee annihilation (interfere with fragmentation)
4.3 in gamma-gamma
4.4 in ee annihilation at threshold (ISR)
5. Theoretical insights
From pedagogic point of view, it is better to start from “Production”

3. Conventional charmonium
How to distinguish from exotic charmonium?
We live in the era, when any newly observed particle is by default an exotic. You need to prove that it can fit the quark model.
We are still disputing on inclusion of these states in our section:
c(2S)
c2 (2P)
X(3940) as c(3S)
X(4160) as c(4S)
X(4630) as ψ(5/6S)
do not contradict to quark model, at least qualitatively
“conventional” observation decay modes
some theorists agree that these can be conventional charmonium states

4. n 2S+1LJ ...10 states were discovered before 1980, no one 1980-2002
Spin quarks
Orbital momentum
Total momentum
n 2S+1LJ
Radial excitation
...10 states were discovered before 1980,
no one
J = S + L
P = (–1)L+1 parity
C = (–1)L+S charge conj.
...5 candidates to the standard charmonium have been observed since 2002 by BB
hc have been observed by CLEO in 2003

5. BaBar & Belle papers related to c(2S)
Reference
Produced in
Decays in
Comments
PRL 89, (2002)
B-decay
KSKπ
First observation in B-decays
PRL 89, (2002)
e+e–  J/ X
inclusive
Confirmation evidence in double charmonium
PRL 92, (2004) γγ
Observation in γγ
PRD 72, (2006)
Measurement of mass and Γ in double charmnoium
PRL 96, (2006)
Measurement of absolute BR
PRL 98, (2007)
Mass measurement in double charmonium
PRD 98, (2008)
Measurement of mass and Γ in B-decays
+ CLEO
PRL 92, (2004) γγ
KSKπ
Observation in γγ

6. c(2S) B  (KSK) K γγ  (KSK) c(2S) e+e– J/ X e+e– J/ X
M = 2654  6  8 MeV/c2
 < 55 MeV
M =  3.4  1.0 MeV/c2
 = 17.0  8.3  2.5 MeV
B  (KSK) K
γγ  (KSK)
c(2S)
M = 2630  12 MeV/c2
M = 3645  5.5  7.9 MeV/c2
 = 22  14 MeV
e+e– J/ X
e+e– J/ X

7. c(2S) parameters Mass Total width γγ width
6±12 MeV (CLEO)
17± 8 MeV (BaBar)
PDG average: Γ = (14 ± 7) MeV
γγ width
Only CLEO result is used in PDG
Absolute Br
Br (c(2S)  KSKπ) = (1.9 ± 1.2) × 10− 2
Derived by PDG from BaBar measurements of Br(B+ → ηc(2S) K+) × Br(ηc(2S) → KKπ) and absolute Br( B+ → ηc(2S) K+ )

8. c2’ in  e+ γ e– D χс2’ Reference Produced in Decays in Comments
PRL 96, (2006) γγ DD
First observation in γγ,
J-determination
Mass, Γ, Γγγ measurements
arXiv:
Observation in γγ,

9. Helicity angle distribution
2006, Belle
M = 3931  4  2 MeV/c2
 = 20  8  3 MeV
Helicity angle distribution
consistent with J=2
J=0 disfavored
2010, BaBar
M =  2.7  1.1 MeV/c2
 = 21.3  6.8  3.6 MeV
Mass is MeV lower than potential model predictions;
width and Γγγ are in agreement with theory

10. X(3940) and X(4160) in e+e− → J/ D*D(*)
References
PRL 98, (2007)
PRL 100, (2008)
M = ±6 MeV
tot = ±12 MeV +7 −6
+26
−15
decay to open charm final states like conventional charmonium
production mechanism fix C=+1
known states produced in e+e− → J/ cc have J=0
not seen in DD decay, exclude JPC=0++
Plausible assignments are JPC=0–+
X(3940) = 31S0 = ηc(3S)
X(4160) = 41S0 = ηc(4S)
For both X(3940) and X(4160) the masses predicted by the potential models are ~100250 MeV higher
6.0 
X(3940) → DD*
M= 15 MeV
tot = 21 MeV
+25
−20
+111
− 61
5.5 
X(4160) → D*D*
ArXiv:
PRL 98,
X(3940) ≠ Y(3940) 10

11. X(4630) in e+e–→Λc+Λc– γISR
References
PRL 101, (2008)
JPC=1– –
dibaryon threshold effect or state?
the shape differs from those for light baryon-antibaryon production at threshold (ee→ΛΛ, ee→pp)
Plausible assignments are
X(4630) = ψ(5S) or ψ(6S)
e+e–→Λc+Λc– γISR
X(4630) ≡ Y(4660)? 11

12. Observation of new decay modes
State
Produced in
Decays in
Reference ηc
B  ηcK ΛΛ
PRL 97, (2006)
ψ(4415)
ISR
DD2
PRL 100, (2008)
ψ(4040)
ψ(4160)
DD, DD*, D*D*
PRD 79, (2009) DD
e+e–→D(*)D(*)γISR
DD*
e+e–→DD2γISR
B ()K
D*D*
BR = (10.5 ± 2.4 ± 3.8)%

13. Parameters (M, width, Br) of known charmonia
State
Produced in
Decays in
Measured
Reference ηc
γγ 
KSKπ
M, Γ
PRL 92, (2004)
B  ηcK(*)
PRL 90, (2003)
γγ* 
M, Γ, FF, Γγγ
PRD 81, (2010)
B  ηcK
KKπ, K*Kπ, pp
J/, ηc
B  J/(ηc)K
pp, ΛΛ
M, Γ, Br
PRL 97, (2006)
ηc, χc0
e+e–  J/ X
exclusive M
PRL 98, (2007) pp
M, Γ, Γγγ
PLB 621, 41 (2005)
ηc, χc0, χc2
4K, 2K2π, 4π
EPJ C53, 1 (2008) γγ
Brγγ
PLB 662, 323 (2008)
Many papers:
do not need to describe the analyses (hopefully will be well described in other sections TWO-PHOTON, ) just review

14. Br (c  γγ) and γγ-width
c parameters
Mass
Total width
Absolute Br
Br (c  γγ) and γγ-width
B (γγ)K
γγ  pp
B  K(cc)
Br (c  KSKπ) = (8.5 ± 1.8 ) × 10− 2

15. Also γγ-width at Q2=0; to be included in PDG
c transition FF
tagged
data
tag
2< Q2<50 GeV2
Also γγ-width at Q2=0; to be included in PDG

16. and χc0, χc2 in γγ J/ψ in ISR Γtot = (93.7 ± 3.5) keV
State
Produced in
Decays in
Measured
Reference
J/
ISR μμ
Γee, Γtot
PRL 97, (2006)
Γtot = (93.7 ± 3.5) keV 
Γee = (5.57 ± 0.19) keV 
Similar accuracy to CLEO measurement and better than BES
and χc0, χc2 in γγ
State
Produced in
Decays in
Measured
Reference
χc2
γγ 
J/ γ
Γγγ*Br
PLB 540, 33 (2002)
χc0, χc2
KSKS
PLB 651, 15 (2007)
ηc, χc0, χc2
4K, 2K2π, 4π
Γγγ*Br, M, Γ
EPJ C53, 1 (2008)

17. ψ(3770) Produced in Decays in Measured Reference ISR DD M, Γ
PRD 76, (2007)
B  ψ(3770) K
PRL 100, (2008)
PRD 77, (2008)
ψ(3770)

18. Production: two body B-decays
State
Produced in
Decays in
Measured
Reference
J/
B  J/ K* ℓℓ
polar.
PLB 538, 11 (2002) ηc
B  ηcK
KSKπ, KKπ, K*Kπ, pp
Br(B  )
PRL 90, (2003)
χc0
B  χc0K
KK, ππ
PRL 88, (2002)
χc2
B  χc2X
J/ γ
PRL 89, (2002)
B  χc2K(*) UL
PLB 634, 155 (2006)
(3770)
B  (3770)K DD
PRL 93,051803(2004)
PRL 100, (2008) hc
B  hcK
ηc γ
PRD 74,  (2006)
Production: ee annihilation
State
Produced in
Decays in
Measured
Reference
J/
e+e–  J/ X ℓℓ
σ, p, θprod, θhel
PRL 88, (2002)
J/; (2S)
e+e–  J/ 0?+
ℓℓ; J/ ππ
σ, θprod, θhel
PRD 70, (2004)
ℓℓ; σ
PRD 72, (2006)
e+e–  J/ cc
PRL 89, (2002)
PRD 79, (2009)

19. Contributors:
principal authors of “observation” papers
# of pages: rough estimate ~ 15
+ 5 for the production