Transcript Standart&Exotic Charmonium vectors

с
-с
Галина Пахлова
ИТЭФ, коллаборация Belle
Экзотические и стандартные
векторные состояния чармония
Conventional Charmonium
in Quark Model
c c
Above open charm threshold
five conventional states are measured
n(2S+1)LJ
• broad states are expected
n radial quantum number
S total spin of q-antiquark
L relative orbital ang. mom.
L = 0, 1, 2 ... correspond to S, P, D
J=S+L
P = (–1)L+1 parity
C = (–1)L+S charge conj.
Below open charm threshold
all expected charmonium states are observed
• most are narrow
Семинар ИТЭФ, 11.11.09
Галина Пахлова
Exotic charmoniumlike states
Multiquark states
–
π c
• Molecular state
c– u
two loosely bound charm mesons
u
March 1976
• quark/color exchange at short distances
• pion exchange at large distance
• Tetraquark
tightly bound four-quark state
November 1976
u––cu
c
Charmonium hybrids
States with excited gluonic degrees of freedom
–
c
c
g
Hadro-charmonium
• Specific charmonium state “coated” by excited
light-hadron matter
π
Threshold effects
c c–
π
• Virtual states at thresholds
• Charmonium states with masses shifted by
nearby D(*)D(*) thresholds
Семинар ИТЭФ, 11.11.09
Search for exotics:
states with ...
 JPC forbidden for
charmonium
 Extremely narrow width
─
 Non-zero charge [cucd],
─ or both
strangeness [cdcs]
─
[cucs]
 Obvious sign of
multiquark states
Exotics more easier to identify
─
among cc─ and bb states
Галина Пахлова
Y(3940)
Z(4430)+
X(3872)
Y(3915)
Z(3930)
Z+2
X(4160)
X(3940)
Y(4008)
Y(4660)
Z+1
Y(4260)
X(4360)
Y(4350)
Y(4350)
Семинар ИТЭФ, 11.11.09
Y(4140)
Галина Пахлова
B-factories
Belle
e+e–→(4S) and nearby continuum:
Ecms ~ 10.6GeV
L ~ 2.1x1034/cm2/s at Belle
950 + 530 fb–1 in total Belle + BaBar
Charmonium from B-meson decays, initial
state radiation (ISR) , double cc production,
continuum production and γγ fusion
Charm factories
CLEO-c
BES-II
e+e– →J/, (2S), (3770)
scan 3.8-4.8 GeV
L~1032/cm2/s
BaBar
Tevatron
D0
CDF
─
pp
collider
E ~ 1.8 TeV
L~ 4fb–1 per experiment
Семинар ИТЭФ, 11.11.09
Галина Пахлова
Charmoniumlike 1– – family
Семинар ИТЭФ, 11.11.09
Галина Пахлова
Use ISR to measure
open&hidden charm exclusive final states
eγ+
e–
e–
cc
e+
s =(Ecm– Eγ)2 – p2
ISR at B factories
Quantum numbers of final states are fixed JPC
= 1– –
Continuous ISR spectrum:
• access to the whole √s interval
• αem suppression compensated by huge luminosity
• comparable sensitivity to energy scan (CLEO-c, BES)
Семинар ИТЭФ, 11.11.09
Галина Пахлова
arXiv:0808.1543
PRL 95,142001(2005)
First Y(4260)
Y(4260)
(2S)
NEW
e+e–→J/ψπ+π– γISR
Y(4260)... Y(4008)?
PRL 99, 182004 (2007)
344±39 ev
8σ
Y(4008)
2-BW fit with interference
• two solutions: different
peak cross sections
-1
233
454fbfb-1
Y(4008)
7.4σ
Y(4260)
550 fb-1
Br(J/ψπ+π–)Γee , eV
PRD74,091104R(2006)
Solution1 Y(4008)
Solution2
ed
m
r
i
f
n
Co
< 0.7 90% CL
Solution1 Y(4260) Solution2
5.4σ
13.3 fb-1
7.5±0.9±0.8
Absence of open charm production
is inconsistent with conventional charmonium
Семинар ИТЭФ, 11.11.09
Галина Пахлова
PRL 96,162003(2006)
11σ
+ J/00 (5.1σ)
PRD 78,
014032
(2008) (2007)
PRL
98, 212001
Y(4360)→ψ(2S)ππ
Y(4660)?
Y(4360)
Y(4660)
6.1σ
+π– γ
Combined
fit to BaBar&Belle
e+e–→ψ(2S)
π
ISR
+
–
+
–
dataY(4360),
on e e →(2S)
π π γ...
ISR
Y(4660)
Best measurements of Y(4360) and Y(4660)
298 fb-1
PRL 99, 142002 (2007)
2-BW fit with interference
Assume all the
cross sections areY(4660)
due to
Y(4360)
Y(4360) and Y(4660)
added coherently
5.8σ
8σ
Br(ψ(2S)π+π–)Γee
, eV
Solution2
Solution1
Absence of open charm production
is inconsistent with conventional
-1
670 fb
charmonium
Y(4360)
Y(4660)
Семинар ИТЭФ, 11.11.09
Галина Пахлова
Y states vs inclusive cross section e+e–→hadrons
if Ruds=2.285±0.03
Y(4660)
ψ
y (4415)
Y(4260)
Y(4325)
Y(4360)
y (4160)
ψ(4160)
ψ
y (4040)
Y(4008)
ψ
y (3770)
R(s) = σ(e+e–→hadrons)/σ(e+e–→μ+μ–) – Ruds
Durham Data Base
Peak positions for M(J/) & M((2S)) significantly different
Y(4260) mass corresponds to dip in inclusive cross section
Семинар ИТЭФ, 11.11.09
Галина Пахлова
Potential models & Y states
No room for Y states among conventional 1– – charmonium
S.Godfrey and N.Isgur PRD32,189 (1985)
33S1 = (4040)
23D1 = (4160)
43S1 = (4415)
4660
4350
4260
4008
masses of predicted
33D1 (4520)
53S1 (4760)
43D1(4810)
are higher (lower)
Семинар ИТЭФ, 11.11.09
Галина Пахлова
Interpretations of Y states
Y(4360) &Y(4660) are conventional charmonia with shifted masses
• Y(4360) = 33D1 , Y(4660) = 53S1
G.J Ding, J.J.Zhu, M.L.Yan, Phys.Rev.D77,014033 (2008)
A.M.Badalyan, B.L.G.Bakker, I.V.Danilkin, Phys.Atom.Nucl.72,638,(2009)
• 43S1 ≠ ψ(4415) = 43D1(4661); Y(4360)=43S1(4389) , Y(4660)=53S1 (4614) or 43D1(4661)
J.Segovia, A.M.Yasser, D.R.Entem, F.Fernandez Phys.Rev.D78,114033,(2008).
Charmonium hybrids
Zhu S.L.; Close F.E.; Kou E. and Pene O.
• The lightest hybrid is expected by LQCD around 4.2 GeV
• The dominant decays Y(4260)→D(*)D(*)π, via virtual D**
Hadro-charmonium
• Specific charmonium state “coated” by excited light-hadron matter
S.Dubinskiy, M.B.Voloshin, A.Gorsky
Multiquark states
• [cq][cq] tetraquark
• DD1 or D*D0 molecules
Maiani L., Riquer V., Piccinini F., Polosa A.D.
Swanson E.; Rosner J.L., Close F.E.
Heavy meson hadronic molecules
• Y(4660) is ψ(2S)f0(980) bound state
F.K.Gou,C.Hanhart, S.Krewald,U.G.Meissner
S-wave charm meson thresholds
Семинар ИТЭФ, 11.11.09
Lui X.
Галина Пахлова
Inclusive cross section
e+e– → hadrons
Parameters of the JPC = 1– – conventional
charmonia ψ(3770), ψ(4040), ψ(4160), ψ(4415)
M, Γtot, Γee remain quite uncertain
and model dependent
To fix the resonance parameters we need to know
their decay channels to take into account their
interference:
• non-resonant contribution
• many open charm thresholds
Семинар ИТЭФ, 11.11.09
Галина Пахлова
BES fit to the inclusive R spectrum
Phys.Lett.B660,315(2008)
All possible two-body decays of ψ(3770),
ψ(4040), ψ(4160), ψ(4415) are included
Rres=RBW+Rint
Resonance shapes
ψ(3770)
ψ(4040)
ψ(4160)
ψ(4415)
Interference term
M, MeV
Γtot , MeV
Γee , keV
3772.92 ± 0.35
27.3 ± 1.0
0.265 ± 0.018
3772.0 ± 1.9
30.4 ± 8.5
0.22 ± 0.05
4039 ± 1
80 ± 10
0.86 ± 0.07
4039.6 ± 4.3
84.5 ± 12.3
0.83 ± 0.20
4153 ± 3
103 ± 8
0.83 ± 0.07
4191.7 ± 6.5
71.8 ± 12.3
0.48 ± 0.22
4421 ± 4
62 ± 20
0.58 ± 0.07
4415.1 ± 7.9
71.5 ± 19.0
0.35 ± 0.12
Семинар ИТЭФ, 11.11.09
Significant effect of interference :
model dependent!
δ, deg
PDG09
0
BES08
PDG09
130 ± 46
BES08
PDG09
293 ± 57
BES08
PDG09
234 ± 88
Галина Пахлова
BES08
To reduce model
dependence
we need to measure
exclusive cross sections to
open charm final states
Width, GeV
?
Potential models & ψ states
Mass spectrum
• In general agreement with data
Open charm decays
• via nonperturbative gluodynamics
?
• difficult to compute
• good probes of strong QCD
Only inclusive measurements
?
More theoretical and experimental
efforts are required
E.Swanson, Phys.Reports 429(2006)
Семинар ИТЭФ, 11.11.09
Галина Пахлова
e+e– →DD via ISR
with full reconstruction
γ
e
e
+
+
–D
e–
Full reconstruction of hadronic part
ISR photon detection is not required
• but used if it is in the detector acceptance
Translate measured DD mass spectrum to cross section
Семинар ИТЭФ, 11.11.09
D
Галина Пахлова
σ(e+e− →DD)
Phys.Rev.D77,011103(2008)
Phys.Rev. D76, 111105(2007)
Phys.Rev. D80, 072001(2009)
D0D0)/σ
(eeD+D−)
σ(ee
at MDD≈M(3770)
Belle: 1.390.310.12 BaBar: 1.78 ± 0.33 ± 0.24
CLEO07 1.258 ± 0.016 ± 0.014
BES06 1.27 ± 0.12 ± 0.08
PDG08 1.260 ± 0.021
Семинар ИТЭФ, 11.11.09
• Broad structure around 3.9 GeV
• in qualitative agreement with coupledchannel model?
• Some structure at 4.0-4.2 GeV
• Statistics are small …ψ(4040)? ψ(4160)?
• Hint of ψ(4415)
Галина Пахлова
(3770) is assumed to be a mixture
of 3D1 – 23S1 cc eigenstates
Anomalous line-shape of
σ(e+e–→hadrons)
around 3.77 GeV
BES: B((3770)→non-DD )=(14.5±1.7±5.8)%
Sum of measured non-DD < 2%
Theory non-DD < 5%
Re-analysis of BES 2003 data
between 3.65 and 3.872 GeV
arXiv:0807.0494
• inconsistent with one (3770)
blue line
Fit by two P-wave BW
• with complete interference 7.6 σ
green line
• without interference 7σ
yellow line
• interference with G(3900) structure
─
seen in σ(e+e–→DD)
by BaBar&Belle
red line
observed cross section - fit with one (3770)
error of the observed cross section
Семинар ИТЭФ, 11.11.09
Галина Пахлова
Two states or
─ production dynamics?
DD
New study
of ψ(3770) →DD
in e+e− →DD
H.B.Li, X.S.Qin, M.Z.Yang; arXiv 0910.4278[hep-ph]
M ψ(3770) 3776 ± 1 MeV
PDG08 fit 3772.92 ± 0.35 MeV
Γ ψ(3770)
28.5 ± 2.2 MeV
PDG08 fit 27.3 ± 1.0 MeV
M G(3900)
Γ G(3900)
3900 ± 20 MeV
52 ± 23 MeV
Fit to BES, Belle, BaBar e+e− →DD cross section data from 3.74 to 4.4 GeV
Include contributions of ψ(3770), ψ(4040), ψ(4160), G(3900) and continuum taking into
account their interference;
•
•
Breit-Wigners for ψ states and Gaussian for G(3900)
the continuum is explained as tail of ψ(2S) with M= 3686.09 MeV
Parameters of ψ(4040), ψ(4160), ψ(2S) are fixed from PDG , parameters of ψ(3770) and
G(3900) are set free
May solve non-DD problem,
more date is needed,
detailed scan at BESIII to be done
Factor of 4 less than Swanson’s predictions
Семинар ИТЭФ, 11.11.09
Галина Пахлова
e+e– →D(*)+D*–
via ISR
with partial reconstruction
–
e
–
D(*)
e
+
+
D*
–
D+D*– & D*+D*–
π
–
D
0
D*–
partial reconstruction
• increase eff ~ 10-20 times
Detection of ISR photon
Translate measured mass recoil against γISR ≡ D(*)+D*– mass spectrum to
cross section
Семинар ИТЭФ, 11.11.09
Галина Пахлова
reconstructed
γ
e
Exclusive e+e–→D(*)D* cross-sections
Phys. Rev. Lett. 98, 092001 (2007)
Phys.Rev. D80, 072001(2009)
D*+D*ψ(4040)
ψ(4160)
D+D*-
550fb–1
ψ(4160)
ψ(4040)
Only statistical errors
Systematic errors are similar
D*D*
•complicated shape of cross section
•clear dip at M(D*D*) ~ 4.26 GeV (similar to inclusive R)
DD*
•broad peak at threshold (shifted relative to 4040 GeV)
Семинар ИТЭФ, 11.11.09
Галина Пахлова
BaBar: e+e−→D(*)D*
Phys.Rev. D79, 092001(2009)
DD
DD*
Full reconstruction of hadronic part
• Both charged and neutral final states
• Fit by sum of ψ states with
fixed masses&widths from PDG (due to limited statistics)
•
No evidence is found for Y(4260)→ DD, DD*,D*D*
D*D*
384 fb-1
Br ratios seem to disagree with potential models …
… uncertainties are too large
Семинар ИТЭФ, 11.11.09
Галина Пахлова
Belle vs BaBar: σ(e+e−→D(*)D*)
Phys. Rev. Lett. 98, 092001 (2007)
Phys.Rev. D79, 092001(2009)
Sum of two body
open charm final states
Belle & BaBar results are in very good agreement
Семинар ИТЭФ, 11.11.09
Галина Пахлова
Three-body final states
γ
e
e
+
D(*
)
e–
D
D0 D(*)− π+
Full reconstruction of hadronic part
ISR photon detection is not required
• but used if it is in the detector acceptance
Translate measured DD(*)π mass spectrum to cross section
Семинар ИТЭФ, 11.11.09
Галина Пахлова
π
reconstructed
+
e+e−  D0D–+ at s ~ 4−5 GeV via ISR
Phys.Rev.Lett.100,062001(2008)
670 fb-1
Clear ψ(4415) →DDπ signal
Семинар ИТЭФ, 11.11.09
Галина Пахлова
Resonant structure in (4415)D0D–+
M(D0π+) vs M(D–π+) from ψ(4415) region
 Clear D*2(2460) signals
 No non-D*2(2460) contribution
Phys.Rev.Lett.100,062001(2008)
M = 4411 ± 7 MeV
Γtot = 77 ± 20 MeV
Nev= 109 ± 25
DD*2(2460)
670 fb-1
~10σ
DDπ non DD*2(2460)
Consistent with BES,
Phys.Lett.B660,315(2008)
PDG06, Barnes at.al
Phys. Rev. D72, 054026 (2005)
σ(e+e–→ψ(4415))×Br(ψ(4415)→DD*2(2460))×Br(D*2(2460) →Dπ) = (0.74 ± 0.17 ± 0.07)nb
Br((4415)  D(D)non D2(2460))/Br((4415) DD*2(2460))<0.22
Семинар ИТЭФ, 11.11.09
Галина Пахлова
The first
charm baryons
final state
Partial reconstruction
with anti-proton tag
e
+
e
+
Reconstruct Λc+
Use antiproton tag from
e
Λ c+
–
inclusive Λc–→p–X
Λ c–
–
p
X
Br(Λc+→pX) = (50±16)%
• combinatorial background suppressed by ≈ 10
Detect the high energy ISR photon
Translate measured mass recoil against γISR ≡ Λc+ Λc– mass
spectrum to cross section
Семинар ИТЭФ, 11.11.09
γ
Галина Пахлова
partial reconstruction with ─
p tag
no Σ–
Λc(2765)
Λc(2880)
Λc
Λc(2625)
Λc(2595)
e+e–→Λc+Λc– γISR
Clear peak in Mrec(Λc+γISR )
distribution at Λc mass
At mass > 2.5 GeV/c2
contributions from Λc+Λc–π0
• could proceed via Λc+Σ– ; violates
isospin and should be strongly
suppressed
and Λc+Λc–π π
• could proceed via Λc+Λc(2595)–,
Λc+Λc(2625)–, Λc+Λc(2765)–,
Λc+Λc(2880)–
Phys.Rev.Lett.101,172001(2008)
Mrecoil(Λc+γISR)
e+e–→Λc+Λc– γISR
Total refection contributions < 5%
(included in systematics)
Look at
Mrecoil(γISR) ≡ Mass spectra of Λc+Λc–
Семинар ИТЭФ, 11.11.09
Галина Пахлова
X(4630)
8.2σ
670 fb-1
Phys.Rev.Lett.101,172001(2008)
Interpretations for X(4630)
e+e–→Λc+Λc– γISR
• no peak-like structure
PRL 99,142002(2007)
PRD73,012005(2006)
ee→ΛΛ via ISR
ee→pp via ISR
• X(4630) ≡ Y(4660)? JPC=1– –
• dibaryon threshold effect?
• like in
• X(4630) = Y(4660) = charmonium state 53S1 or 43D1
J.Segovia, A.M.Yasser, D.R.Entem, F.Fernandez
• Charmonium state 63S1 B.Q.Li and K.T.Chao
• Threshold effect E.Beveren, G.Rupp
•Y(4660) =ψ(2S)f0(980) bound state
F.K.Gou,C.Hanhart, S.Krewald,U.G.Meissner
• Point-like baryons R.B.Baldini, S.Pacetti, A.Zallo
• X(4630) = Y(4660) D.V.Bugg
•Семинар
X(4630)ИТЭФ,
= Y(4660)
= tetraquark D.Ebert, R.N.Fausov,
V.O. Galkin
11.11.09
Галина Пахлова
B→pΛπ, J/ψ→γpp
PRL 97, 242001 (2006)
6.2σ
─ –
B–→Λc+p
π
Searching
for hybrids
via their
favorite decay
modes
Семинар ИТЭФ, 11.11.09
Галина Пахлова
e+e− D0D*–+
at s ~ 4−5 GeV via ISR
Full reconstruction
No extra tracks
Detection of γISR is not required
• if γISR is detected
• M(D0D*–+γISR) is required ~ Ecm
γISR is not detected
γISR is detected
arXiv:0908.0231
670 fb-1
Consistent with ISR production
Combinatorial bgs are estimated
from sidebands D and D*
Other bgs are small and taken
into account
Small efficiency at threshould
Семинар ИТЭФ, 11.11.09
Галина Пахлова
in e+e– → D0 D*–π+ γisr
D1(2420)0 → D*– π+ ← D2(2460)
D0 D*–π+ from D0D1(2420)0 & D0D2(2460)0
DD*π & DD1 &D*D2
Семинар ИТЭФ, 11.11.09
D*–π+
Галина Пахлова
2420
D0 π +
2460
e+e– →ψ(4415) → D0D2(2460)0 → D0 D–π+ is measured
Main problem is to separate D0D1(2420)0 from D0D2(2460)0
• D1(2420)0 : Γtot = 20.4 ± 1.7 MeV
• D2(2460)0 : Γtot = 43 ± 4 MeV (PDG08)
Both DD1 & D*D2 are seen ...
but the statistics is not enough to study their mass spectra!
Exclusive e+e− D0D*–+ cross-section
arXiv:0908.0231
Upper Limit
Y(4260)
ψ(4415)
ψ(4415)
No evident structures: only UL’s !
Baseline fit:
• RBW for (4415) & threshold
function for non-resonant contribution
without interference between
amplitudes
To obtain limits on XD0D*–+,
X=Y(4260), Y(4360), Y(4660), X(4630)
perform four fits each with one of the
X states, (4415) and non-resonant
contribution
Interference could increase these UL’s by
factors of 2−4 depending on the final state
Fix masses and total widths from PDG
(for destructive solutions)
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
Семинар ИТЭФ, 11.11.09
Галина Пахлова
DDπ
Contribution
to the
inclusive
cross section
D*D*
DD
Семинар ИТЭФ, 11.11.09
DD*
Галина Пахлова
Y(4260)
Y(4360)
ψ(4040)
ψ(4160)
Y(4008)
D*D*
PRL98, 092001 (2007)
DD*
PRD77,011103(2008)
DD
PRL100,062001(2008)
ψ(4415)
?
DDπ
σ(e+e–→open charm) via
Y states vs exclusive cross sections
ISR
Y(4008) mass coincides with DD* peak
Y(4260) mass corresponds to dip in D*D*
cross section
Around Y(4360) mass all measured cross
sections are smooth
Y(4660) mass is close to Λc+Λc– peak
Signigicant “peak-like” enhancement
near 3.9 GeV in ee→DD
coupled channel effect? or something else?
PRL101,172001(2008)
Λc+Λc–
Семинар ИТЭФ, 11.11.09
Y(4660)
arXiv:0908.0231
DD*π
Галина Пахлова
E.Eichten, et al Phys.Rev D21, 203,(1980)
DD
DDπ
DD*
D*D*
Sum of all exclusive contributions
DD*π
Λ+c Λ–c
Семинар ИТЭФ, 11.11.09
Only small room for unaccounted contributions
• Charm strange final states
Limited inclusive data above 4.5 GeV
• Charm baryons final states
Галина Пахлова
S.Godfrey, arXiv:0910.3409 [hep-ph]
How to fit
measured
cross section?
Four (five?) ψ states,
five (three?) Y states
and at least
11 open charm
thresholds!
Семинар ИТЭФ, 11.11.09
Галина Пахлова
Cornell Coupled Channel model: R in the threshold region
arXiv:0801.3418
E.Eichten QWG08
Complicated thresholds behaviour
Need improved model to describe standard and to search for new states
Семинар ИТЭФ, 11.11.09
Галина Пахлова
c
c
In conclusion
Семинар ИТЭФ, 11.11.09
Галина Пахлова
Experiment
Six exclusive open charm final states are measured
DD, D*D, D*D*, DDπ, DD*π, ΛcΛc
Their sum is close to e+e– → hadrons
Belle & BaBar & Cleo cross section measurements are nicely consistent
with each other
In charm meson final states no evident peaks corresponding to members of
charmoniumlike 1– – family are found !
ΛcΛc
•
enhancement at threshold, quantum numbers, mass and width are consistent
with Y(4660)
• Various interpretations
... it’s time to describe these data by realistic common fit and
to extract realistic parameters of ψ states ...
Семинар ИТЭФ, 11.11.09
Галина Пахлова
All presented cross
sections can be
found in Durham
Data Base
Theoretical efforts to describe charm components of
inclusive cross section are kindly requested!
Семинар ИТЭФ, 11.11.09
Галина Пахлова
Спасибо
Семинар ИТЭФ, 11.11.09
Галина Пахлова