ATHIC 2010 T. Umeda (Hiroshima Univ.) 1 Heavy Quarkonium in QGP on Heavy Quarkonium in QGP on the Lattice the Lattice Takashi Umeda Takashi Umeda 3rd Asian Triangle Heavy-Ion Conference 3rd Asian Triangle Heavy-Ion Conference CCNU, Wuhan, China, October 18-20, 2010 CCNU, Wuhan, China, October 18-20, 2010 /19
Heavy Quarkonium in QGP on the Lattice. Takashi Umeda. 3rd Asian Triangle Heavy-Ion Conference CCNU, Wuhan, China, October 18-20, 2010. /19. Contents of this talk. from the Phenix group web-site. Introduction -- J/ ψ suppression - PowerPoint PPT Presentation
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ATHIC 2010 T. Umeda (Hiroshima Univ.) 1
Heavy Quarkonium in QGP on Heavy Quarkonium in QGP on the Latticethe Lattice
Takashi UmedaTakashi Umeda
3rd Asian Triangle Heavy-Ion Conference3rd Asian Triangle Heavy-Ion ConferenceCCNU, Wuhan, China, October 18-20, 2010CCNU, Wuhan, China, October 18-20, 2010
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Contents of this talk
IntroductionIntroduction
-- J/-- J/ψψ suppression suppression
-- Lattice studies with Maximum Entropy Method (MEM)-- Lattice studies with Maximum Entropy Method (MEM)
Confined phase:Confined phase: linear raising potentiallinear raising potential bound state of c – cbound state of c – c
De-confined phase:De-confined phase: Debye screeningDebye screening scattering state of c - cscattering state of c - c ( J/ψ dissociation )( J/ψ dissociation )
T.Hashimoto et al.(’86), T.Hashimoto et al.(’86), Matsui&Satz(’86)Matsui&Satz(’86)
J/ψ & ηJ/ψ & ηcc survive till 1.62 Tsurvive till 1.62 Tcc
dissociate at 1.87Tdissociate at 1.87Tcc
Charmonium correlator on the lattice Spectral function (SPF)
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Results on P-wave states Results on P-wave states A.Jakovac et al. (’07)A.Jakovac et al. (’07)
Drastic change in Drastic change in χχcc correlator above T correlator above Tcc
MEM results indicateMEM results indicate
χχcc dissociation just above Tdissociation just above Tcc (?) (?)
P-wave states (χc) in charmonium
Grecon is a charmonium correlator constructed with SPF at T=0. No change in SPF at T>0
leads to G/Grecon = 1
““Default model” is Default model” is input information for MEM analysisinput information for MEM analysisDefault model dependence is Default model dependence is one of systematic errors one of systematic errors
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Possible J/ψ suppression scenario
E705 Collab.(’93) E705 Collab.(’93)
When When χχcc or/and ψ’ dissociate just above T or/and ψ’ dissociate just above Tcc, ,
part of J/part of J/ψψ suppression occurs suppression occurs even if J/even if J/ψψ survives in QGP. survives in QGP.
Sequential charmonium dissociationSequential charmonium dissociationF. Karsch et al. (’05)F. Karsch et al. (’05)
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Contents of this talk
IntroductionIntroduction
-- J/-- J/ψψ suppression suppression
-- Lattice studies with Maximum Entropy Method (MEM)-- Lattice studies with Maximum Entropy Method (MEM)
Other approaches to study charmonium dissociationOther approaches to study charmonium dissociation
SummarySummary
from the Phenix group web-site
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infinite volume case finite volume case
In a finite volume (e.g. Lattice simulations), In a finite volume (e.g. Lattice simulations), discrete spectra does not always indicate bound states !discrete spectra does not always indicate bound states !
Spectral functions in a finite volume
Momenta are discretized in finite (V=LMomenta are discretized in finite (V=L33) volume) volume
ppii/a = 2n/a = 2niiππ/L (n/L (nii=0,±1,±2,…) for Periodic boundary condition=0,±1,±2,…) for Periodic boundary condition
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H. Iida et al. (’06)
M
BC BC’
bound
M
BC BC’
scattering
r
φ(r)bound
0
r
φ(r)scattering
0
The wave functions are localized,their energies are insensitive to B.C.
The momenta depends on BC,the scattering state energies are sensitive to B.C.
Other approaches to study charmonium dissociation
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Quark boundary conditions (B.C.) in space (finite volume on the lattice)
Clear signals of bound states even at T=2.3TClear signals of bound states even at T=2.3Tcc
χχc1c1(1P)(1P)
χχc1c1(2P)(2P)
H. Ohno et al. (’08)H. Ohno et al. (’08)
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(Bethe-Salpeter) (Bethe-Salpeter) “Wave function” at T=2.3T“Wave function” at T=2.3Tcc
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Summary on lattice studies of charmonium dissociations
Because of MEM results on the lattice,Because of MEM results on the lattice,- J/ψ state survives till 1.5T- J/ψ state survives till 1.5Tcc or more or more
and, dissociates around 1.5-2.0Tand, dissociates around 1.5-2.0Tcc
-- χ χcc states dissociate just above T states dissociate just above Tcc
are widely believed.are widely believed.
Analysis taking the zero mode into accountAnalysis taking the zero mode into accountNo significant spectral changes in QGP (except for zero mode)No significant spectral changes in QGP (except for zero mode)
MEM results include large default model dependenceMEM results include large default model dependence
Other approaches to study charmonium dissociationOther approaches to study charmonium dissociation
indicate no clear signal of dissociationindicate no clear signal of dissociation
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Summary and Outlook
Puzzle of J/ψ suppression in QGPPuzzle of J/ψ suppression in QGP
J/ψ should dissociate at very high temperatureJ/ψ should dissociate at very high temperature
because of the asymptotic freedom.because of the asymptotic freedom.
Lattice QCD has never seen such evidences yet (except for MEM).Lattice QCD has never seen such evidences yet (except for MEM).
High temperature calculations are time consuming on the lattice.High temperature calculations are time consuming on the lattice.
Non-MEM studies at very high temperature (T/TNon-MEM studies at very high temperature (T/Tcc=3~5) are desired.=3~5) are desired.
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Thank you for your attention !
Buckup slides
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Temp. dependence of ( Bethe-Salpeter ) Temp. dependence of ( Bethe-Salpeter ) “Wave function” “Wave function”
Wave functions at finite temperature
using the eigen functions of the variational methodusing the eigen functions of the variational method
we can extract the wave functions of each stateswe can extract the wave functions of each states
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Summary and future plan
We investigated TWe investigated Tdisdis of charmonia from Lattice QCD of charmonia from Lattice QCD
using another approach to study charmonium at T>0 using another approach to study charmonium at T>0
without Bayesian analysiswithout Bayesian analysis
- Wave function (Volume dependence)- Wave function (Volume dependence)
The result may affect the scenario of J/The result may affect the scenario of J/ψψ suppression. suppression.
Future planFuture plan Interpretations of the experimental results on J/Interpretations of the experimental results on J/ψψ suppression suppression Higher Temp. calculations ( T/Tc=3~5 )Higher Temp. calculations ( T/Tc=3~5 )
Full QCD calculations ( Nf=2+1 Wilson is now in progress )Full QCD calculations ( Nf=2+1 Wilson is now in progress )
No evidence for unbound c-c quarks up to T = 2.3 TcNo evidence for unbound c-c quarks up to T = 2.3 Tc
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Maximum Entropy Method (MEM)
Other lattice studies:Other lattice studies:
T.Umeda et al.(’02), S.Datta et al.(’04), T.Umeda et al.(’02), S.Datta et al.(’04),
Asakawa&Hatsuda(’04), A.Jakovac et al.(’07), G.Aatz et al.(’06)Asakawa&Hatsuda(’04), A.Jakovac et al.(’07), G.Aatz et al.(’06)
all calculations conclude thatall calculations conclude that J/J/ψψ survives till 1.5T survives till 1.5Tcc or higher or higher