Ágnes Mócsy22 nd Winter Workshop. La Jolla. 03 15 061 Quarkonia Above Deconfinement Ágnes Mócsy 22 nd Winter Workshop. La Jolla. 03 11-19 06

Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06

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Quarkonia Above Quarkonia Above DeconfinementDeconfinement

Quarkonia Above Quarkonia Above DeconfinementDeconfinement

Ágnes Mócsy

22nd Winter Workshop. La Jolla. 03 11-19 06


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conclusion as outlineconclusion as outline

potential models with certain screened potentials can reproduce qualitative features of the lattice spectral function survival of 1S state and melting of 1P state BUT the temperature dependence of the meson correlators is not reproduced

our simple toy model is consistent with the lattice datasimple toy model is consistent with the lattice data

in collaboration with Péter Peterczkyin collaboration with Péter Peterczky


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why are heavy quarkonia interesting ?

why are heavy quarkonia interesting ?

modification of their properties in a hot medium can tell us about deconfinement

color screening length < size of resonance

sequential suppression

QGP Debye screening unbinding of heavy q states

J/ suppression

T

’(2S) c(1P) J/(1S)0.9fm0.9fm 0.7f0.7f

mm0.4f0.4fmm

Matsui, Satz 86Matsui, Satz 86

Karsch,Mehr,Satz 88Karsch,Mehr,Satz 88


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how we study quarkonia/deconfinement ?

how we study quarkonia/deconfinement ?

Experiment Theory Phenomenology

Potential modelsNRQCD, pNRQCD Lattice QCD

PHENIXSTAR

today: Potential model versus Lattice


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potential modelspotential models

( ) ( )

( )( )( )T TV ,T 1

Tr ra

r e er

μ μσ

μ− − = − + −

V( )a

r rr

σ=− +

success for quarkonia spectroscopyobtainable from QCDavailable on the lattice

predicted J/ disappears at 1.1Tc

T = 0

T > Tc

nonrelativistic. interaction of q and antiq mediated by a potential

we don’t knowwe don’t know

confined

deconfinedJ/

rr

V(r)V(r)

in context of deconfinement: can a T-dependent potential describe the medium modification and dissolution of quarkonia? and what is the potential?

Digal,Petreczky,Satz 01Digal,Petreczky,Satz 01


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from the latticefrom the lattice

€

G τ ,T( )Grecon τ ,T( )

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

no change in mass (amplitude) at least until 1.5 Tc

cspectral function σ(,T)

correlatorcorrelator

= 1 when = 1 when σ(,T) = = σ(,T=0)

MMEEMM

- correlation function of hadronic currents

c

UmedaUmedaHatsuda,AsakawaHatsuda,AsakawaDatta et al 04Datta et al 04Petreczky et al 06Petreczky et al 06


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c0

state disappearsstate disappears

reliable

1S exists at 1.5Tc 1P dissolved at 1.1Tc

not so reliable

++

c0


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model spectral functionmodel spectral function

€

σ(ω)

€

G τ ,T( ) = σ ω,T( )K τ ,ω,T( )dω∫

€

2M i∑ Fi2δ ω2 −M i

2( )

€

m0ω2 f ω,s0( )θ ω − s0( )

T = 0T Tc

++=

Mi bound state massFi decay constant energy above which no clear

resonance observed experimentallyabove which q travel freely with mass mq(T)

s0 continuum threshold


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screened potentialscreened potential

s0 decreases

asympotic value of the potentialdetermines the continuum threshold:

ss00(T) = 2m + V∞(T)

masses, amplitudes obtained solving the Schrödinger eq w/ masses, amplitudes obtained solving the Schrödinger eq w/ T-dependent screened Cornell potentialT-dependent screened Cornell potential

( ) ( )

( )( )( )T TV ,T 1

Tr ra

r e er

μ μσ

μ− − = − + −

gap between resonance and gap between resonance and threshold decreasesthreshold decreases


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quarkonia propertiesquarkonia properties

masses amplitudes

but lets look at the correlators …but lets look at the correlators …

no substantial changes sharp drop above Tc


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1P scalar charmonium 1P scalar charmonium

correlator increases at 1.1Tc qualitative agreement with lattice even though the state is melted the correlator is enhanced due to threshold reduction


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1S pseudoscalar charmonium1S pseudoscalar charmonium

lattice: no change until ~2Tc

potential model: moderate increase due to threshold reduction, then decrease due to amplitude reduction

no agreement with lattice


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include excited statesinclude excited states

10-20 % drop in the c correlator due to the melting of the 2S state

effect not seen on the lattice


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lattice internal energy as potential

lattice internal energy as potential

even worse!even worse!

disfavored by lattice

conceptually difficult to identifyconceptually difficult to identify

Shuryak, Zahed 04Shuryak, Zahed 04Wong 05Wong 05Alberico et al 05Alberico et al 05

large increase near Tc

leads to increase of mass and amplitude

&

Kaczmarek et al Kaczmarek et al


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what we learned sofarwhat we learned sofar

reduces the amplitudes reduces the threshold melts higher excited states

Screening in the plasma seems not to be responsible for quarkonia suppression

possible reason: time scale of screening is not small compared to the time scale of heavy quark motion

screening

c and c correlators don’t agree with lattice


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a toy modela toy model

€

G T > Tc( )G T = 0( )

no temperature dependent screening continuum threshold reduction no modification of the 1S properties - we use PDG melting of 2S and 3S states melting of the 1P state

determine

T = 0

T Tc

1S 2S 3S

T = 0

T Tc

1P


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appropriate choice of s0 can keep the c correlator unchanged and the c0 correlator increased

G/Grecon as seen on the lattice


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conclusionsconclusions

Temperature-dependence of heavy quarkonia lattice correlators are not explained with either screened Cornell potential or lattice internal energy as potential.

Screening likely not responsible for quarkonia suppression.

A simple toy model with no screening does a better job.

Ongoing: beyond simple toy model …Ongoing: beyond simple toy model …

a complete calculation of nonrelativistic Green functiona complete calculation of nonrelativistic Green function

Documents

Ágnes Mócsy22 nd Winter Workshop. La Jolla. 03 15 061 Quarkonia Above Deconfinement Ágnes Mócsy 22 nd Winter Workshop. La Jolla. 03 11-19 06