TIFR Mumbai India Feb 12-14 2008 Ágnes Mócsy at RBRC 1 Quarkonium as Signal of Deconfinement...

Ágnes Mócsy at RBRC

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TIFR Mumbai India Feb 12-14 2008

Quarkonium as Signal of Deconfinement

Ágnes MócsyÁgnes MócsyQuickTime™ and a

TIFF (Uncompressed) decompressorare needed to see this picture.

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Thanks to Sourendu, Saumen, Rajeev, Rajiv!Thanks to Sourendu, Saumen, Rajeev, Rajiv!


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In this talk:In this talk:

• Why quarkonium at finite T interesting

• Initial interpretation of quarkonium lattice data

• Results from potential model. Comparison to lattice

• Upper limit binding energies. Estimates of upper

limit dissociation T

• Comments on the potential

• Conclusions

based on Á. Mócsy, P. Petreczky Phys. Rev. D 77, 014501 (2008)

Phys. Rev. Lett. 99, 211602 (2007)

based on Á. Mócsy, P. Petreczky Phys. Rev. D 77, 014501 (2008)

Phys. Rev. Lett. 99, 211602 (2007)


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can signal QGP formation in heavy ion collisionsMatsui and Satz (1986)

Screening in deconfined matter weakens potential (force) between heavy quark and antiquark.

Color ScreeningColor Screening J/ meltingJ/ melting

confined

deconfinedJ/

r

V(r)


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Screening in deconfined matter weakens potential (force) between heavy quark and antiquark.

Strong screening seen in Lattice Strong screening seen in Lattice

RBC-Bielefeld Collab.

(2007)

Free energy of a static Q-Qbar in Nf=2+1


Poster by K.Petrov Poster by K.Petrov

With increasing T screening sets in at shorter and shorter distances


Model independent statement Range of interaction between Q and Qbar is strongly reduced



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RBC-Bielefeld Collab.

(2007)

Free energy of a static Q-Qbar in Nf=2+1


QGP thermometer QGP thermometer

T/TC 1/r [fm-1]

(1S)

J/(1S)

c(1P)

’(2S)

b’(2P)

’’(3S)



Strong screening seen in Lattice Strong screening seen in Lattice Model independent statement Range of interaction between Q and Qbar is strongly reduced



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J/ suppression measured at SPS and RHIC

J/ suppression measured at SPS and RHIC


QGP thermometer QGP thermometer

T/TC 1/r [fm-1]

(1S)

J/(1S)

c(1P)

’(2S)

b’(2P)

’’(3S)

Must know quarkonia properties, dissociation temperatures!Must know quarkonia properties, dissociation temperatures!

NA50 at SPS (0<y<1)PHENIX at RHIC (|y|<0.35)

Bar: uncorrelated errorBracket : correlated errorGlobal error = 12% is not shown


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Potential ModelsLattice QCD


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Spectral Functions Extracted from Lattice Spectral Functions Extracted from Lattice

Common interpretation: 1S ground state survives (unaffected) well above TC

Common interpretation: 1S ground state survives (unaffected) well above TC

c

Would the J/ survive unaffected in the QGP up to 1.5-2Tc even though strong screening is

present ?

Would the J/ survive unaffected in the QGP up to 1.5-2Tc even though strong screening is

present ?

Jakovác,Petreczky,Petrov,Velitsky PRD (2007)

Started an avalanche of new potential model works to explain J/ survival Digal et al,Shuryak,Zahed,Blaschke,Wong, Rapp, Alberico,Manarelli, Cabrera, …

Unified treatment of bound-, scattering states, threshold effectsAsakawa, Hatsuda, Umeda, Datta et al, Iida, Jakovac et al, Aarts et al …


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Euclidean-time Correlators Euclidean-time Correlators

€

G τ ,T( ) = σ ω,T( )K τ ,ω,T( )dω∫

€

Grec τ ,T( ) = σ ω,T = 0( )K τ ,ω,T( )dω∫

3. In ratio lattice artifacts understood - Mócsy, Petreczky EJP 2007

€

G τ ,T( ) = σ ω,T( )K τ ,ω,T( )dω∫

to answer, Look at

1. Numerical results more reliable - directly measured on the LatticeBecause:

CorrelatorMEASURED

Spectral Function

EXTRACTED with MEM

Kernel cosh[(-1/2T)]/sinh[/2T]

2. Ratio of correlators eliminates trivial T-dependence of K

Mócsy, Petreczky PRD 2005


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Initial interpretation:

€

G τ ,T( ) = σ ω,T( )K τ ,ω,T( )dω∫

€

Grec τ ,T( ) = σ ω,T = 0( )K τ ,ω,T( )dω∫ 1spectral function modified,state melts

= 1 spectral function unchanged, state survives

J/(c) survives up to 1.5-2Tc and c melts by 1.1 Tc has been reported

Potential models must be checked for agreement with lattice data on correlators as wellPotential models must be checked for agreement with lattice data on correlators as well

calculate in potential model

compare to

lattice data

c

Datta et al PRD 04

c

Datta et al PRD 04


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in contradiction with statements made in the literature

Correlator at T=0

Correlator at T=0

Relativistic continuum seen on the lattice

Relativistic continuum seen on the lattice

Mócsy, Petreczky, PRD 08

Non-relativistic continuum

Relativistic continuum

Lattice data from Datta et al, PRD 05


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Potential Model with Nf=0

Potential Model with Nf=0

c

No resonance-like structures at 1.2Tc Seemingly contradicts

previous claims.

No resonance-like structures at 1.2Tc Seemingly contradicts

previous claims.

Near threshold there is an enhancement above free quark

propagation. Indicates correlation.

Near threshold there is an enhancement above free quark

propagation. Indicates correlation.

Pseudoscalar results with potential constrained by lattice free energy data

Threshold enhancement compensates for melting of

states

Threshold enhancement compensates for melting of

states

Lattice data

~ 2%For the First Time Agreement between potential model and lattice correlators to few % and for all states

For the First Time Agreement between potential model and lattice correlators to few % and for all states

Jakovác et al PRD (07)

Lattice data is consistent with J/ melting above Tc

Lattice data is consistent with J/ melting above Tc

Details cannot be resolved Details cannot be resolved


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Constant contribution in the correlator

quark number susceptibility

1.5 Tc

Zero-mode contributionZero-mode

contribution

Threshold enhancement compensates for dissolution of states

Threshold enhancement compensates for dissolution of states

Scalar channel contains low frequency contribution at finite temperature

Bound and unbound Q-Qbar pairs

(>2mQ)

Bound and unbound Q-Qbar pairs

(>2mQ)

Quasi-free heavy quarks interacting with the medium

Quasi-free heavy quarks interacting with the medium

following Umdeda, PRD 07

Zero mode is not present in the derivative of correlator

Dissolution of the c does not lead to large increase in the correlator


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When Ebin < T, state is waekly bound and thermal fluctuations can destroy it. Do not need to reach the usual Ebin=0 to dissociate a state.

When Ebin < T, state is waekly bound and thermal fluctuations can destroy it. Do not need to reach the usual Ebin=0 to dissociate a state.

Potential constrained by lattice free energy data w. realistic quark masses

Ebin = 2mq+V∞(T)-M distance between peak position and continuum threshold

Spectral function may show resonance-like peak structures but binding energy can be small

Spectral function may show resonance-like peak structures but binding energy can be small

{

Potential Model with Nf=2+1

Potential Model with Nf=2+1


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€

Ebin < Tweak binding

€

Ebin > Tstrong binding

Binding Energy Upper Limit Binding Energy Upper Limit 1. Use the most confining potential still consistent with full QCD lattice data on static Q-antiQ energies

2. Estimate dissociation rate due to thermal activation (width) Ebin< T following Kharzeev,McLerran,Satz, PLB 953. Ad hoc choice dissociation condition: Thermal width > 2 x Binding energy


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Dissociation Temperatures in QCD Upper Bound estimateDissociation Temperatures in QCD Upper Bound estimate

Mócsy, Petreczky PRL (2007)

Implications for heavy ion phenomenology to consider

• Similarity of J/ RAA at SPS and RHIC?• Upsilon suppression at RHIC?

Calibration of the QGP thermometerCalibration of the QGP thermometer

T/TC 1/r [fm-1]

(1S)

J/(1S) ’(2S)

c(1P) ’(2S)b’(2P) ’’(3S)TC

2

1.2

b(1P)


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Set of potentials at 1.2Tc

T=0 potential

lattice internal energy

lattice free energy

pseudoscalar

G/Grec from set of potentials all agree with correlator lattice data

G/Grec from set of potentials all agree with correlator lattice data

Comment on the potentialComment on the potential


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For the first Time agreement is found between a potential model and lattice correlators for all

states

For the first Time agreement is found between a potential model and lattice correlators for all

states

SummarySummary

Lattice data are consistent with J/ dissociation just above Tc

what has changed? Flatness of G/Grec and lattice spectral function peak does not necessarily imply survival, as it was thought before.Increase in correlators is due to different physics, not dissociation. G/Grec are flat in all channels. Indication of Q-Qbar correlation.

Lattice data are consistent with J/ dissociation just above Tc

what has changed? Flatness of G/Grec and lattice spectral function peak does not necessarily imply survival, as it was thought before.Increase in correlators is due to different physics, not dissociation. G/Grec are flat in all channels. Indication of Q-Qbar correlation.

Determined upper limit on binding energies using lattice data on free and internal energy together

with potential model.

Determined upper limit on binding energies using lattice data on free and internal energy together

with potential model. Estimate of upper limit on dissociation temperatures indicate that most states except the and b are

dissolved close to Tc

Estimate of upper limit on dissociation temperatures indicate that most states except the and b are

dissolved close to Tc


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****The END****

TIFR Mumbai India Feb 12-14 2008 Ágnes Mócsy at RBRC 1 Quarkonium as Signal of Deconfinement...

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