Ágnes mócsy22 nd winter workshop. la jolla. 03 15 061 quarkonia above deconfinement Ágnes mócsy...
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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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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c0
state disappearsstate disappears
reliable
1S exists at 1.5Tc 1P dissolved at 1.1Tc
not so reliable
++
c0
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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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
Ágnes Mócsy 22nd Winter Workshop. La Jolla. 03 15 06
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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