Nuclear Equation of State

1
Chiral Symmetry Restoration and J/?
Suppressionas probes of Phase Transition
2
Chiral Symmetry Restoration and J/?
/SUPPRESSIONPapers

• Aspects of Chiral Symmetry
• Volker Koch nucl-th/9706075
• Journal-ref Int.J.Mod.Phys. E6 (1997) 203-250
• Asymptotic Freedom
• Frank Wilczek hep-ph/0502113
• Why is a nucleon bound?
• Edward Shuryak hep-ph/9603354
• Journal-ref Nucl.Phys. A606 (1996) 201-214
• --------------------------------------------------
  ------------------------------------
• J/? /SUPPRESSION BY QUARK-GLUON PLASMA FORMATION
• T. MATSUI and H. SATZ
• Volume 178, number 4 PHYSICS LETTERS B 9 October
  1986
• J/? /SUPPRESSION (Experimental paper)
• M.C. Abreu et al. Physics Letters B
  450(1999)456466

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Chiral Symmetry Restoration

• Is a symmetry of QCD in the limit of vanishing
  quark masses.
• Current quark mass is finite, but small
• ? chiral symmetry are approximate symmetry of
  strong interactions

4
Resonance Response to Medium

• Resonances below and above Tc
• Gluonic bound states
• (e.g. Glueballs) Shuryak hep-ph/0405066
• Initial deconfinement conditions Determine T
  initial through
• J/Y and ? state dissociation
• Chiral symmetry restoration
• Mass and width of resonances
• ( e.g. f leptonic vs hadronic decay,
• chiral partners r and a1)
• Hadronic time evolution
• From hadronization (chemical
• freeze-out) to kinetic freeze-out.

LHC?
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Resonances are the Key Probe for QCD Phase
Transition(s)
BR KK-/BR ee-
Because of lifetime and strong interactions with
the medium, light vector mesons are the only
probe of chiral symmetry restoration
Because of color screening in the medium, heavy
vector mesons are the most sensitive probe of
deconfinement conditions
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Chiral Symmetry Restoration
Leptonic and hadronic decay f(1020) ? e e- ,
mm- BR 0.0003 f(1020) ? K K-
BR 0.50 Mass (e e-)
0.001 GeV Mass (K K- ) 0.987 GeV Effective
mass drops ? hadronic decay closes up. ?
Increase of BR ratio
We expect a initial density in a heavy ion
reaction of 5-20 times of r0
T. Hatsuda and S. Lee Phys. Rev. C46 (1992) 34
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f Meson at SPS
CERES f ? KK-, ee- A. Marin SQM2004
f ? m m-
Hadronic channel less signal in low pt lower
yield (factor 42)
Rob Veenhof
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CERES low-mass ee mass spectrum
Almost final results from the 2000 run PbAu at
158 GeV per nucleon
comparison to the hadron decay cocktail
Enhancement over hadron decay cocktail for mee
gt 0.2 GeV 2.43?0.21 (stat) for 0.2 GeVltmeelt 0.6
GeV 2.8?0.5 (stat)

• Absolutely normalized spectrum
• Overall systematic uncertainty of
• normalization 21

9
NA60 f and r from Leptonic Decay
NA60 (mm-) Data
A. Falco QM2005
w
f

• NA60 f shows no mass shift or
• width broadening
• ? Medium ?

J. Ruppert HotQuarks 2006
Only broadening of ? observed but no mass shift
Regeneration in hadronic phase feeds into
leptonic decay as well
10
Chiral Symmetry Restoration
Vacuum
At Tc Chiral Restoration
Data ALEPH Collaboration R. Barate et al. Eur.
Phys. J. C4 409 (1998)
Measure chiral partners Near critical temperature
Tc (e.g. r and a1)
a1 ?p g
Ralf Rapp (Texas AM) J.Phys. G31 (2005)
S217-S230
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Sensitivity to Deconfinement Conditions
Matsui Satz (1986) (Phys. Lett. B178 (1986)
416) Color screening of heavy quarks in QGP leads
to heavy resonance dissociation.
Thermometer for early stages Tdis(Y(2S)) lt
Tdis(?(3S))lt Tdis(J/Y) ? Tdis(?(2S)) lt Tdis(?(1S))
Lattice QCD predictions
Decay modes ?c ? J/Y g ?b ? ? g
Lattice QCD SPS TInitial 1.5 Tc RHIC
TInitial 2 Tc LHC T Initial ? Tc
The suppression of heavy quark states signature
of deconfinement at QGP.
J/Y (cc-bar) ? e e-, m m- ? (bb-bar)
? e e-, m m-
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Signal Extraction
Proton-Proton Data
Proton-Proton Data
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Gold-Gold Central Case
J/y ? mm AuAu 20 Central S/B 0.1
J/y ? ee AuAu 10 Central S/B 0.25
Detailed event mixing background subtraction,
modified log likelihood fitting, and careful
systematic error determination.
No signal in North Muon Arm 0-10 central AuAu
(only signal in South Arm). Detector occupancy
more than 2 x HIJING! PHENIX CDR expected S/Bgt1.

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Probing initial temperature
NA38 / NA50
At the CERN-SPS the y is suppressed much more
than the J/y. At RHIC we expect larger J/y
suppression. Recombination of J/y ?
J/y
y
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The Central Regionin Drell-Yan Production