Экзотические и стандартные векторные состояния...
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-. с. с. Галина Пахлова ИТЭФ , коллаборация Belle. Экзотические и стандартные векторные состояния чармония. c. c. Above open charm threshold five conventional states are measured broad states are expected. Conventional Charmonium in Quark Model. n (2S+1) L J - PowerPoint PPT PresentationTRANSCRIPT
Экзотические и стандартные векторные состояния чармония
Галина ПахловаИТЭФ, коллаборация Belle
сссс --
Семинар ИТЭФ, 11.11.09 Галина Пахлова
Conventional Charmonium in Quark Model c c
Above open charm thresholdfive conventional states are measured
• broad states are expected
Below open charm threshold all expected charmonium states are observed
• most are narrow
n(2S+1)LJ
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 + LP = (–1)L+1 parity
C = (–1)L+S charge conj.
Семинар ИТЭФ, 11.11.09 Галина Пахлова
Search for exotics: states with ... JPC forbidden for charmonium Extremely narrow width Non-zero charge [cucd], strangeness [cdcs] or both [cucs]
Obvious sign of multiquark states
─
─
─
Exotic charmoniumlike statesMultiquark states
• Molecular state
two loosely bound charm mesons• quark/color exchange at short distances
• pion exchange at large distance
• Tetraquark
tightly bound four-quark state
Charmonium hybridsStates with excited gluonic degrees of freedom
Hadro-charmonium • Specific charmonium state “coated” by excited
light-hadron matter
Threshold effects• Virtual states at thresholds
• Charmonium states with masses shifted by nearby D(*)D(*) thresholds
Exotics more easier to identify among cc and bb states ──
c c–g
u– cuc–
c c–π
π
March 1976
November 1976
πc c–uu–
Семинар ИТЭФ, 11.11.09 Галина Пахлова
X(3872)
Z(3930)
Y(3940)
X(3940)
Y(4350)
Y(4660)
Y(4260)
X(4360)
X(4160)
Y(3915)
Y(4140)Y(4350)
Z(4430)+
Z+1
Z+2
Y(4008)
Семинар ИТЭФ, 11.11.09 Галина Пахлова
Charm factoriesCLEO-c BES-IIe+e– →J/, (2S), (3770) scan 3.8-4.8 GeVL~1032/cm2/s
Belle
BaBar
TevatronD0 CDF pp collider E ~ 1.8 TeV
L~ 4fb–1 per experiment
─
B-factoriese+e–→(4S) and nearby continuum: Ecms ~ 10.6GeVL ~ 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
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
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)
ee––
ee++ee++
cc
γγs =(Ecm– Eγ)2 – p2
ccee––
ee++
Семинар ИТЭФ, 11.11.09 Галина Пахлова
PRL 99, 182004 (2007)
550 fb-1
2-BW fit with interference • two solutions: different peak cross sections
Y(4008)7.4σ Y(4260)
PRL 99, 182004 (2007)
550 fb-1
2-BW fit with interference • two solutions: different peak cross sections
Y(4008)7.4σ Y(4260)
e+e–→J/ψπ+π– γISR
Y(4260)... Y(4008)?Y(4260)
454 fb-1
344±39 ev
Y(4008)
arXiv:0808.1543
NEW
Absence of open charm production is inconsistent with conventional charmonium
< 0.7 90% CL
7.5±0.9±0.8
Br(J/ψπ+π–)Γee , eV
Solution1 Y(4008) Solution2
Solution1 Y(4260) Solution2
(2S)First Y(4260)PRL 95,142001(2005)
233 fb-1
8σ
(2S)First Y(4260)PRL 95,142001(2005)
233 fb-1
8σ
Confirmed PRL 96,162003(2006)
+ J/00 (5.1σ)
11σConfirmed PRL 96,162003(2006)
+ J/00 (5.1σ)
11σPRD74,091104R(2006)
13.3 fb-15.4σ
PRD74,091104R(2006)
13.3 fb-15.4σ
Семинар ИТЭФ, 11.11.09 Галина Пахлова
Y(4360)→ψ(2S)ππ
PRL 98, 212001 (2007)
298 fb-1
Y(4660)?
e+e–→ψ(2S) π+π– γISR
Y(4360), Y(4660) ...
Absence of open charm production is inconsistent with conventional charmonium
Y(4360) 8σ
Y(4660) 5.8σ
670 fb-1
PRL 99, 142002 (2007)
2-BW fit with interference
Y(4660) 6.1σ
Y(4360)
PRD 78, 014032 (2008) Combined fit to BaBar&Belle data on e+e–→(2S) π+π– γISR
Assume all the cross sections are due to Y(4360) and Y(4660) added coherently
Br(ψ(2S)π+π–)Γee , eVSolution1 Solution2
Y(4360)
Y(4660)
Best measurements of Y(4360) and Y(4660)
Семинар ИТЭФ, 11.11.09 Галина Пахлова
Y states vs inclusive cross section e+e–→hadrons
Peak positions for M(J/) & M((2S)) significantly different
Y(4260) mass corresponds to dip in inclusive cross section
y(3
770)
if Ruds=2.285±0.03 Durham Data Base
Y(4
008)
y(4
040)
y(4
160)
Y(4
260)
Y(4
325) y
(441
5)
Y(4
660)
ψ(3
770)
if Ruds=2.285±0.03 Durham Data Base
Y(4
008)
ψ(4
040)
ψ(4
160)
Y(4
260)
Y(4
360) ψ
(441
5)
Y(4
660)
R(s) = σ(e+e–→hadrons)/σ(e+e–→μ+μ–) – Ruds
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)
masses of predicted
33D1 (4520)
53S1 (4760)
43D1(4810) are higher (lower)
4260
4660
4008
4350
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 Maiani L., Riquer V., Piccinini F., Polosa A.D. • DD1 or D*D0 molecules 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 Lui X.
Семинар ИТЭФ, 11.11.09 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
All possible two-body decays of ψ(3770), ψ(4040), ψ(4160), ψ(4415) are included
M, MeV Γtot , MeV Γee , keV δ, deg
ψ(3770) 3772.92 ± 0.35 27.3 ± 1.0 0.265 ± 0.018 PDG09
3772.0 ± 1.9 30.4 ± 8.5 0.22 ± 0.05 0 BES08
ψ(4040) 4039 ± 1 80 ± 10 0.86 ± 0.07 PDG09
4039.6 ± 4.3 84.5 ± 12.3 0.83 ± 0.20 130 ± 46 BES08
ψ(4160) 4153 ± 3 103 ± 8 0.83 ± 0.07 PDG09
4191.7 ± 6.5 71.8 ± 12.3 0.48 ± 0.22 293 ± 57 BES08
ψ(4415) 4421 ± 4 62 ± 20 0.58 ± 0.07 PDG09
4415.1 ± 7.9 71.5 ± 19.0 0.35 ± 0.12 234 ± 88 BES08
Significant effect of interference : model dependent!
To reduce model dependence
we need to measure exclusive cross sections to
open charm final states
Resonance shapes Interference term
Rres=RBW+Rint
Phys.Lett.B660,315(2008) BES fit to the inclusive R spectrum
Семинар ИТЭФ, 11.11.09 Галина Пахлова
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
?
?
?
Width, GeVWidth, GeV
E.Swanson, Phys.Reports 429(2006)
Семинар ИТЭФ, 11.11.09 Галина Пахлова
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
e+e– →DD via ISR with full reconstruction
e–
e+
not reconstructed
if undetectable
e+
DD
reconstructed
DD
γ
–
Семинар ИТЭФ, 11.11.09 Галина Пахлова
Phys.Rev. D76, 111105(2007)
σ(e+e− →DD)Phys.Rev.D77,011103(2008)
Phys.Rev. D80, 072001(2009)
• Broad structure around 3.9 GeV • in qualitative agreement with coupled-channel model?
• Some structure at 4.0-4.2 GeV • Statistics are small …ψ(4040)? ψ(4160)?
• Hint of ψ(4415)
σ(ee D0D0)/σ (eeD+D−) at MDD≈M(3770)
Belle: 1.390.310.12 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 Галина Пахлова
Anomalous line-shape of σ(e+e–→hadrons) around 3.77 GeV
(3770) is assumed to be a mixture of 3D1 – 23S1 cc eigenstates
Re-analysis of BES 2003 data between 3.65 and 3.872 GeV
observed cross section - fit with one (3770) error of the observed cross section
arXiv:0807.0494
Two states or DD production dynamics? ─
• 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
─
BES: B((3770)→non-DD )=(14.5±1.7±5.8)%Sum of measured non-DD < 2%Theory non-DD < 5%
Семинар ИТЭФ, 11.11.09 Галина Пахлова
New study of ψ(3770) →DD
in e+e− →DD
Fit to BES, Belle, BaBar e+e− →DD cross section data from 3.74 to 4.4 GeVInclude 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
M ψ(3770) 3776 ± 1 MeVPDG08 fit 3772.92 ± 0.35 MeVΓ ψ(3770) 28.5 ± 2.2 MeV PDG08 fit 27.3 ± 1.0 MeV
M G(3900) 3900 ± 20 MeVΓ G(3900) 52 ± 23 MeV
H.B.Li, X.S.Qin, M.Z.Yang; arXiv 0910.4278[hep-ph]
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
D+D*– & D*+D*– 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
e+e– →D(*)+D*–
via ISR with partial reconstruction
D(*)
+
γe–
D0
D*–π–
e+
e–
reconstructed
not reconstructed
but constrained
Семинар ИТЭФ, 11.11.09 Галина Пахлова
Exclusive e+e–→D(*)D* cross-sectionsPhys.Rev. D80, 072001(2009)
ψ(4160)
ψ(4040)
ψ(4160)
ψ(4040)
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)
Only statistical errors Systematic errors are similar
D*+D*-
D+D*-
Phys. Rev. Lett. 98, 092001 (2007)
Y(4260)
ψ(4160)
ψ(4040)
ψ(4415)
550fb–1
Семинар ИТЭФ, 11.11.09 Галина Пахлова
• 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)
BaBar: e+e−→D(*)D*
No evidence is found for Y(4260)→ DD, DD*,D*D*
DD
DD*
D*D*
384 fb-1
Phys.Rev. D79, 092001(2009)
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. D79, 092001(2009)
Phys. Rev. Lett. 98, 092001 (2007)
Sum of two body open charm final states
Belle & BaBar results are in very good agreement
Семинар ИТЭФ, 11.11.09 Галина Пахлова
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
Three-body final states
DD(*(*
))
e–
e+
not reconstructed
if undetectable
e+
DD
ππ
reconstructed
γ
Семинар ИТЭФ, 11.11.09 Галина Пахлова
e+e− D0D–+ at s ~ 4−5 GeV via ISR
Clear ψ(4415) →DDπ signal
Consistent with ISR production
670 fb-1
Phys.Rev.Lett.100,062001(2008)
Семинар ИТЭФ, 11.11.09 Галина Пахлова
Resonant structure in (4415)D0D–+
Br((4415) D(D)non D2(2460))/Br((4415) DD*2(2460))<0.22
M(D0π+) vs M(D–π+) from ψ(4415) region Clear D*
2(2460) signals No non-D*
2(2460) contribution
DDπ non DD*2(2460)
DD*2(2460)
~10σ
670 fb-1
Phys.Rev.Lett.100,062001(2008)
σ(e+e–→ψ(4415))×Br(ψ(4415)→DD*2(2460))×Br(D*
2(2460) →Dπ) = (0.74 ± 0.17 ± 0.07)nb
M = 4411 ± 7 MeVΓtot = 77 ± 20 MeV
Nev= 109 ± 25
Consistent with BES,Phys.Lett.B660,315(2008)
PDG06, Barnes at.al Phys. Rev. D72, 054026 (2005)
Семинар ИТЭФ, 11.11.09 Галина Пахлова
Reconstruct Λc+
Use antiproton tag from inclusive Λc–→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
Partial reconstruction with anti-proton tag
The first charm baryons
final state
p–
X
reconstructede–
e+
not reconstructed
Λc–
e+
γ
X
Λc+
Семинар ИТЭФ, 11.11.09 Галина Пахлова
e+e–→Λc+Λc
– γISR
Λ c sidebands
Mrecoil(Λc+γISR)
Λc
Λc(2625)Λc(2595)
Λc(2765)Λc(2880)
no Σ–
partial reconstruction with p tag ─
Clear peak in Mrec(Λc+γISR )
distribution at Λc massAt 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)–
Total refection contributions < 5% (included in systematics)
Look at Mrecoil(γISR) ≡ Mass spectra of Λc
+Λc–
670 fb-1
X(4630) 8.2σ
Phys.Rev.Lett.101,172001(2008)
e+e–→Λc+Λc
– γISR
Семинар ИТЭФ, 11.11.09 Галина Пахлова
PRL 99,142002(2007)
ee→ΛΛ via ISR
PRD73,012005(2006)
ee→pp via ISR
PRL 99,142002(2007)
ee→ΛΛ via ISR
PRD73,012005(2006)
ee→pp via ISR
• no peak-like structure
• 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
• X(4630) = Y(4660) = = tetraquark D.Ebert, R.N.Fausov, V.O. Galkin
• X(4630) ≡ Y(4660)? JPC=1– –
e+e–→Λc+Λc
– γISR
Phys.Rev.Lett.101,172001(2008) Interpretations for X(4630)
PRL 97, 242001 (2006)
6.2σ B–→Λc+p π–─
PRL 97, 242001 (2006)
6.2σ B–→Λc+p π–─
• dibaryon threshold effect?• like in B→pΛπ, J/ψ→γpp
Семинар ИТЭФ, 11.11.09 Галина Пахлова
Searching for hybridsvia their
favorite decay modes
Семинар ИТЭФ, 11.11.09 Галина Пахлова
e+e− D0D*–+ at s ~ 4−5 GeV via ISR
Combinatorial bgs are estimated from sidebands D and D*
Other bgs are small and taken into account
Small efficiency at threshould
Full reconstructionNo extra tracksDetection of γISR is not required • if γISR is detected • M(D0D*–+γISR) is required ~ Ecm
Consistent with ISR production
γISR is not detected
γISR is detected
670 fb-1
arXiv:0908.0231
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
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!
DD*π & DD1 &D*D2
2420
2460
D0 π + D*–π+
Семинар ИТЭФ, 11.11.09 Галина Пахлова
ψ(4415)
Upper Limit 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 XD0D*–+, X=Y(4260), Y(4360), Y(4660), X(4630)
perform four fits each with one of the X states, (4415) and non-resonant contribution
Fix masses and total widths from PDG
Exclusive e+e− D0D*–+ cross-section
σ(e+e–→ψ(4415))×Br(ψ(4415)→D0D*–π+)< 0.76 nb at 90% CLBr(ψ(4415)→ D0D*–π+) < 10.6 % at 90% CL
Interference could increase these UL’s by factors of 2−4 depending on the final state (for destructive solutions)
UL at 90% CL
Y(4260)
ψ(4415)
arXiv:0908.0231
Семинар ИТЭФ, 11.11.09 Галина Пахлова
Contribution to the
inclusive cross section
D*D*
DDπ
DD*
DD
Λ c+ Λ c
–
DD* π
Семинар ИТЭФ, 11.11.09 Галина Пахлова
Y states vs exclusive cross sectionsY(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
σ(e+e–→open charm) via ISRD*D*
DD*
ψ(4
040)
ψ(4
160)
Y(4
008)
ψ(4
415)
Y(4
660)
Y(4
260)
Y(4
360)
DD
DDπ
Λc+Λc
–
?
PRD77,011103(2008)
PRL100,062001(2008)
PRL98, 092001 (2007)
PRL101,172001(2008)
DD*π arXiv:0908.0231
E.Eichten, et al Phys.Rev D21, 203,(1980)
coupled channel effect? or something else?
30 years ago!
Семинар ИТЭФ, 11.11.09 Галина Пахлова
DD DD* D*D*
DDπ
DD*π
Λ+c Λ–
c
Sum of all exclusive contributions
Only small room for unaccounted contributions• Charm strange final states
Limited inclusive data above 4.5 GeV• Charm baryons final states
Семинар ИТЭФ, 11.11.09 Галина Пахлова
How to fit measured
cross section?
Four (five?) ψ states, five (three?) Y states
and at least11 open charm
thresholds!
S.Godfrey, arXiv:0910.3409 [hep-ph]
Семинар ИТЭФ, 11.11.09 Галина Пахлова
Cornell Coupled Channel model: R in the threshold region E.Eichten QWG08
Complicated thresholds behaviourNeed improved model to describe standard and to search for new states
arXiv:0801.3418
Семинар ИТЭФ, 11.11.09 Галина Пахлова
In conclusion
cc
Семинар ИТЭФ, 11.11.09 Галина Пахлова
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 ...
Experiment
Семинар ИТЭФ, 11.11.09 Галина Пахлова
Theoretical efforts to describe charm components of inclusive cross section are kindly requested!
All presented cross sections can be
found in Durham Data Base
Семинар ИТЭФ, 11.11.09 Галина Пахлова
Спасибо