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Quarkonium as Signal of Deconfinement. Ágnes Mócsy. Thanks to Sourendu, Saumen, Rajeev, Rajiv!. In this talk:. Why quarkonium at finite T interesting Initial interpretation of quarkonium lattice data Results from potential model. Comparison to lattice

Quarkonium as Signal of Deconfinement

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Quarkonium as Signal of Deconfinement

Ágnes Mócsy

Thanks to Sourendu, Saumen, Rajeev, Rajiv!

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 onÁ. Mócsy, P. PetreczkyPhys. Rev. D 77, 014501 (2008)

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

Color Screening

J/ melting

V(r)

confined

deconfined

J/

r

can signal QGP formation in heavy ion collisions

Matsui and Satz (1986)

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

Color Screening

J/ melting

RBC-Bielefeld Collab. (2007)

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

can signal QGP formation in heavy ion collisions

Matsui and Satz (1986)

Poster by K.Petrov

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

Strong screening seen in Lattice

Model independent statement

Range of interaction between Q and Qbar is strongly reduced

With increasing T screening sets in at shorter and shorter distances

Color Screening

J/ melting

T/TC

1/r [fm-1]

(1S)

J/(1S)

b’(2P)

c(1P)

’’(3S)

RBC-Bielefeld Collab. (2007)

’(2S)

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

can signal QGP formation in heavy ion collisions

Matsui and Satz (1986)

Strong screening seen in Lattice

QGP thermometer

Model independent statement

Range of interaction between Q and Qbar is strongly reduced

With increasing T screening sets in at shorter and shorter distances

Color Screening

J/ melting

T/TC

1/r [fm-1]

NA50 at SPS (0<y<1)

PHENIX at RHIC (|y|<0.35)

(1S)

J/(1S)

Bar: uncorrelated error

Bracket : correlated error

Global error = 12% is not shown

b’(2P)

c(1P)

’’(3S)

’(2S)

can signal QGP formation in heavy ion collisions

Matsui and Satz (1986)

J/ suppression measured at SPS and RHIC

QGP thermometer

Must know quarkonia properties, dissociation temperatures!

Potential Models

Lattice QCD

c

Spectral Functions Extracted from Lattice

Unified treatment of bound-, scattering states, threshold effects

Asakawa, Hatsuda, Umeda, Datta et al, Iida, Jakovac et al, Aarts et al …

Common interpretation:

1S ground state survives (unaffected) well above TC

Started an avalanche of new potential

model works to explain J/ survival

Digal et al,Shuryak,Zahed,Blaschke,Wong, Rapp, Alberico,Manarelli, Cabrera, …

Jakovác,Petreczky,Petrov,Velitsky PRD (2007)

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

to answer, Look at

Euclidean-time Correlators

Because:

Mócsy, Petreczky PRD 2005

1. Numerical results more reliable - directly measured on the Lattice

Correlator

MEASURED

Spectral Function

EXTRACTEDwith MEM

Kernel

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

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

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

= 1

spectral function unchanged, state survives

- 1
spectral function modified,

state melts

c

c

Datta et al PRD 04

Datta et al PRD 04

compare to lattice data

calculate in potential model

Initial interpretation:

J/(c)survives up to1.5-2Tcand cmelts by 1.1 Tchas been reported

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

Correlator at T=0

Lattice data from Datta et al, PRD 05

Relativistic continuum

Non-relativistic continuum

Mócsy, Petreczky, PRD 08

Relativistic continuum seen on the lattice

in contradiction with statements made in the literature

~ 2%

Lattice data

Potential Model with Nf=0

Pseudoscalarresults with potential constrained by lattice free energy data

c

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

No resonance-like structures at 1.2Tc Seemingly contradicts previous claims.

Details cannot be resolved

Jakovác et al PRD (07)

Lattice data is consistent with J/ melting above Tc

Near threshold there is an enhancement above free quark propagation. Indicates correlation.

Threshold enhancement compensates for melting of states

1.5 Tc

Zero mode is not present in the derivative of correlator

followingUmdeda, PRD 07

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

Zero-mode contribution

Scalar channel contains low frequency contribution at finite temperature

Bound and unbound

Q-Qbar pairs (>2mQ)

Quasi-free heavy quarks interacting with the medium

Constant contribution in the correlator

quark number susceptibility

Threshold enhancement compensates for dissolution of states

Potential Model with Nf=2+1

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

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

{

Ebin = 2mq+V∞(T)-M

distance between peak position and continuum threshold

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.

strong binding

weak binding

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

followingKharzeev,McLerran,Satz, PLB 95

3. Ad hoc choice dissociation condition: Thermal width > 2 x Binding energy

T/TC

1/r[fm-1]

(1S)

2

b(1P)

1.2

J/(1S) ’(2S)

b’(2P)

’’(3S)

TC

c(1P)

’(2S)

Dissociation Temperatures in QCD Upper Bound estimate

Mócsy, Petreczky PRL (2007)

Calibration of the QGP thermometer

- Implications for heavy ion phenomenology to consider
- Similarity of J/ RAA at SPS and RHIC?
- Upsilon suppression at RHIC?

T=0 potential

lattice internal energy

lattice free energy

Comment on the potential

Set of potentials at 1.2Tc

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

pseudoscalar

Summary

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

- 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.

Estimate of upper limit on dissociation temperatures indicate that most states except the andbare dissolved close to Tc