Transcript CONVENTIONAL CHARMONIA Section Editors BaBar: Riccardo Faccini Belle: Pavel Pakhlov Theory: Nora Brombilla Outline of the section. 0.

CONVENTIONAL CHARMONIA
Section Editors
BaBar: Riccardo Faccini
Belle: Pavel Pakhlov
Theory: Nora Brombilla
Outline of the section.
0. Introduction
1. 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”
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
Spin quarks
n
...10 states were
discovered
before 1980,
Total momentum
2S+1L
J
Radial excitation
Orbital momentum
no one
1980-2002
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
BaBar & Belle papers related to c(2S)
Reference
Produced in
Decays in
Comments
PRL 89, 102001
(2002)
PRL 89, 142001
(2002)
PRL 92, 142002
(2004)
PRD 72, 0311001
(2006)
PRL 96, 052002
(2006)
B-decay
KSKπ
e+e–  J/ X
inclusive
γγ
KSKπ
First observation in Bdecays
Confirmation evidence in
double charmonium
Observation in γγ
e+e–  J/ X
inclusive
B-decay
inclusive
PRL 98, 082001
(2007)
PRD 98, 012006
(2008)
e+e–  J/ X
inclusive
B-decay
KSKπ
γγ
KSKπ
Measurement of mass and
Γ in double charmnoium
Measurement of absolute
BR
Mass measurement in
double charmonium
Measurement of mass and
Γ in B-decays
+ CLEO
PRL 92, 142001
(2004)
Observation in γγ
M = 2654  6  8
 < 55 MeV
MeV/c2
B  (KSK) K
c(2S)
M = 3630.8  3.4  1.0 MeV/c2
 = 17.0  8.3  2.5 MeV
γγ  (KSK)
c(2S)
M = 2630  12 MeV/c2
e+e–
J/ X
M = 3645  5.5  7.9 MeV/c2
 = 22  14 MeV
e+e– J/ X
c(2S) parameters
Mass
Total 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+ )
c2’ in 
e+
e–
γ
γ
e+
χс2’
D
D
e–
Reference
Produced in
Decays in
Comments
PRL 96, 082003
(2006)
γγ
DD
arXiv:1002.0281
γγ
DD
First observation in γγ,
J-determination
Mass, Γ, Γγγ measurements
Observation in γγ,
J-determination
Mass, Γ, Γγγ measurements
2006, Belle
M = 3931  4  2 MeV/c2
 = 20  8  3 MeV
consistent with J=2
J=0 disfavored
2010, BaBar
M = 3926.7  2.7  1.1 MeV/c2
 = 21.3  6.8  3.6 MeV
Mass is 50-100 MeV lower than potential model
predictions;
width and Γγγ are in agreement with theory
X(3940) and X(4160) in e+e− → J/ D*D(*)
PRL 98, 082001 (2007)
PRL 100, 202001 (2008)
M = 3942 +7
−6 ±6 MeV
tot =37 +26
±12 MeV
−15
6.0 
X(3940) →
M= 4156
tot = 139
5.5 
+25
−20
+111
− 61
DD*
15 MeV
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++

21 MeV
X(4160) → D*D*
ArXiv:0810.0358
PRL 98, 082001
X(3940) ≠ Y(3940)
References
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
X(4630) in
References
e+e–→Λc+Λc– γISR
e+e–→Λc+Λc– γISR
PRL 101, 172001 (2008)
JPC=1– –
 dibaryon threshold effect or state?
 the shape differs from those for light
baryon-antibaryon production at
threshold (ee→ΛΛ, ee→pp)

X(4630) ≡ Y(4660)?
PRL 99,142002(2007)
PRD73,012005(2006)
ee→ΛΛ via ISR
ee→pp via ISR
Plausible assignments are
X(4630) = ψ(5S) or ψ(6S)
Observation of new decay modes
State
Produced in
Decays in
Reference
ηc
B  ηcK
ΛΛ
PRL 97, 162003 (2006)
ψ(4415)
ISR
DD2
PRL 100, 062001 (2008)
ψ(4040)
ψ(4160)
ψ(4415)
ISR
DD, DD*, D*D*
PRD 79, 092001 (2009)
DD
e+e–→D(*)D(*)γISR
e+e–→DD2γISR
DD*
B ()K
D*D*
BR = (10.5 ± 2.4 ± 3.8)%
Parameters (M, width, Br) of known charmonia
State
Produced in
Decays in
Measured
Reference
ηc
γγ 
KSKπ
M, Γ
PRL 92, 142002 (2004)
ηc
B  ηcK(*)
KSKπ
M, Γ
PRL 90, 071801 (2003)
ηc
γγ* 
KSKπ
M, Γ, FF, Γγγ
PRD 81, 052010 (2010)
ηc
B  ηcK
KKπ, K*Kπ, pp
M, Γ
PRL 90, 071801 (2003)
J/, ηc
B  J/(ηc)K
pp, ΛΛ
M, Γ, Br
PRL 97, 162003 (2006)
ηc, χc0
e+e–  J/ X
exclusive
M
PRL 98, 082001 (2007)
ηc
γγ 
pp
M, Γ, Γγγ
PLB 621, 41 (2005)
4K, 2K2π, 4π
M, Γ, Br
EPJ C53, 1 (2008)
γγ
Brγγ
PLB 662, 323 (2008)
ηc, χc0, χc2 γγ 
ηc
B  ηcK
Many papers:
 do not need to describe the analyses (hopefully will be well described in other
sections TWO-PHOTON, ) just review

Mass
c parameters
Total width
Br (c  γγ) and γγ-width
Absolute Br
B  K(cc)
B (γγ)K
γγ  pp
Br (c  KSKπ) = (8.5 ± 1.8 ) × 10− 2
c transition FF
tag
tagged
data
2< Q2<50 GeV2
Also γγ-width at Q2=0; to be included in PDG
J/ψ in ISR
State
Produced in
Decays in
Measured
Reference
J/
ISR
μμ
Γee, Γtot
PRL 97, 162003 (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
γγ 
KS KS
Γγγ*Br
PLB 651, 15 (2007)
ηc, χc0, χc2
γγ 
4K, 2K2π, 4π
Γγγ*Br, M, Γ
EPJ C53, 1 (2008)
ψ(3770)
Produced in
Decays in
Measured
Reference
ISR
DD
M, Γ
PRD 76, 111105 (2007)
B  ψ(3770) K DD
M, Γ
PRL 100,092001 (2008)
B  ψ(3770) K DD
M, Γ
PRD 77, 011102 (2008)
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, 071801 (2003)
χc0
B  χc0K
KK, ππ
Br(B  )
PRL 88, 031802 (2002)
χc2
B  χc2X
J/ γ
Br(B  )
PRL 89, 011803 (2002)
χc2
B  χc2K(*)
J/ γ
UL
PLB 634, 155 (2006)
(3770)
B  (3770)K DD
Br(B  )
PRL 93,051803(2004)
PRL 100, 092001 (2008)
hc
B  hcK
UL
PRD 74, 012007 (2006)
ηc γ
Production: ee annihilation
State
Produced in
Decays in
Measured
Reference
J/
e+e–  J/ X
ℓℓ
σ, p, θprod, θhel
PRL 88, 031802 (2002)
J/; (2S)
e+e–  J/ 0?+
ℓℓ; J/ ππ
σ, θprod, θhel
PRD 70, 071102 (2004)
J/
e+e–  J/ 0?+
ℓℓ;
σ
PRD 72, 0311001 (2006)
J/
e+e–  J/ cc
ℓℓ
σ, p, θprod, θhel
PRL 89, 011803 (2002)
PRD 79, 072004 (2009)
Contributors:
principal authors of “observation” papers
# of pages: rough estimate ~ 15
+ 5 for the production